Low-side intakes for downhole pumps, and related apparatuses and methods

Abstract

Various downhole tools are discussed, including intakes for downhole pumps to avoid and separate gas and solids. Low-side intakes with external baffles are discussed. Long low-side intakes with increasing size inlet openings along an inner housing provide a more uniform inflow profile over an extended length to improve efficiency of gas avoidance. A tubular for use in a low-side intake, eccentrically weighted with one edge of a flat plate rolled inside the other to form an overlapping portion. Low-side intakes with eccentric external baffles to orient an inner housing with its inlet openings toward the low-side. A permeable baffle to isolate the turbulent and gassy wellbore flow from the liquid gathering space below the permeable baffle nearby low-side inlet openings. A multistage intake with stages comprising both low-side and dip-tube geometries – first where an inner housing comprises low-side inlet openings and inner and outer housings are rigidly connected and orient as-one in the wellbore – or second where a swivelling inner eccentrically weighted baffle orients an opening within the separation chamber of each stage toward a low-side. An articulating swivel that allows free rotation of an eccentrically weighted low-side intake and angular misalignment of the axes. Flex joints or articulating swivels between stages of a low-side intake. A liner with a low-side intake. Related apparatuses and methods are discussed.

Description

LOW-SIDE INTAKES FOR DOWNHOLE PUMPS, AND RELATED APPARATUSES AND METHODS TECHNICAL FIELD

[0001] This document relates to intakes and gas separators for downhole pumps, and related apparatuses and methods. The present disclosure relates generally to the separation of gas and liquid phases of downhole fluids at or near the intake of a downhole pumps to maximize pump efficiency and drawdown and production rates, especially in gassy wellbores, and high deviation or horizontal wellbores with unstable flow regimes. Configurations with filters, solids separation, articulating swivels, deployment as a liner, and multistage low-side intakes are disclosed.BACKGROUND

[0002] The following paragraphs are not an admission that anything discussed in them is prior art or part of the knowledge of persons skilled in the art. Hydrocarbons, such as oil and gas, are produced or obtained from subterranean reservoir formations that may be located onshore or offshore through wells. Pump systems, for example, reciprocating pumps (of which most are rod-driven and in industry the acronym used is Sucker Rod Pumps (SRP)), progressive cavity pump (PCP), electrical submersible pump (ESP) may be used when reservoir pressure alone is insufficient to produce hydrocarbons from a well. Presence of free gas in a fluid being pumped and the resulting multiphase flow behavior of the fluid has a detrimental effect on pump performance, reliability, and efficiency. In extreme situations, high concentrations of gas within a pump result in a condition commonly referred to as “gas lock”, where gas is so prevalent within the pump, that flow ceases in the intended direction. SPR’s may re-prime themselves in operation, while ESPs typically require a shut-down and re-start in response to a gas lock event; in all systems efficiency is lost and wear on pump components is accelerated during gas lock events. Reducing the concentration of gas improves pump performance and for ESPs, may improve the operating temperature and stability of the motor. Low-side intakes (sometimes known as gas-avoider intakes) have been used effectively for pumps installed at high inclinations (typically above 60°).

[0003] SUMMARY

[0004] A downhole low-side intake is disclosed comprising: a tubular, which has an eccentric center of mass that is configured to rotate within the wellbore to align inlet openings in the tubular toward a low-side of the wellbore; and an external crosswise baffle on the tubular.

[0005] A downhole low-side intake is disclosed comprising: a tubular, which is eccentrically weighted to allow free axial rotation of the tubular relative to a downstream end of the downhole low-side intake to align one or more inlet openings in the tubular toward a low-side of the downhole low-side intake; and a crosswise baffle on the tubular.

[0006] Long low-side intakes may be more effective with a tapered flow area of the inlet openings, with restricted inlet openings toward the downstream end. The tapered flow area of inlet openings providing a more uniform inflow profile thereby reducing the downwards velocity in the annular space between the intake the casing where gas separation / avoidance occurs.

[0007] An improved design for orienting an inner housing with its inlet openings toward the low-side is proposed with eccentric crosswise baffles. A downhole low-side intake is disclosed comprising: an inner housingthat is rigidly coupled to eccentric crosswise baffles, and configured with at least one row of inlet openings oriented toward the low-side.

[0008] An improved design is proposed for eccentric weighting of tubular for use in a low-side intake, with one edge of a flat plate rolled inside the other to form an overlapping portion of the tubular. An improved design is proposed with a telescoping tubular component, which reduces the fluid velocity in the annulus toward the upstream end of the intake device.

[0009] An improved design for isolating the turbulent and gassy wellbore flow in the wellbore from the low-side liquid gathering space near low-side inlet openings is proposed using a permeable baffle extending the length of an intake stage.

[0010] An improved design is proposed for multistage combination low-side and dip-tube intake apparatus where the inner and outer housings are rigidly connected and orient as-one in the wellbore.

[0011] A downhole low-side intake is disclosed comprising: an inner housing and an outer housing that are rigidly connected and orient as-one in a wellbore; two or more intake stages, each stage: being bounded by a crosswise baffle on an uphole and a downhole end, the inner housing comprising low-side oriented inlet openings that are located toward a downhole end of a stage, and comprising an outer housing having at least one opening to make it permeable, the at least one opening being located toward an uphole end of a stage.

[0012] A multistage low-side combination low-side and dip-tube intake apparatus is proposed where a crosswise baffle orients an opening within each stage toward a low-side. In embodiments the opening may allow for radial flow or axial flow.

[0013] A downhole low-side intake is disclosed comprising: an inner housing and an outer housing, and two or more intake stages, each stage: being bounded by a crosswise baffle on an uphole and a downhole end, comprising an inner housing with inlet openings that are located toward a downhole end of a stage comprising a permeable outer housing having at least one opening, the at least one opening being located toward an uphole end of a stage, and an inner eccentric weighted baffle located at an axial position between openings of an outer housing and inlet openings of an inner housing, and the inner eccentric weighted baffle configured to rotate freely within the annulus between the inner housing and the outer housing to align an opening toward the low-side.

[0014] An articulating downhole swivel is disclosed that is configured to allow free rotation of an eccentrically weighted downhole low-side intake coupled thereto, and to allow relative movement to cause angular misalignment of axes of the downhole low-side intake and a tubular located uphole of the swivel.

[0015] A downhole low-side intake is disclosed with a flexible connection between intake stages.

[0016] Previously proposed low-side intakes typically contain a rotational swivel to allow an eccentrically weighted component to correctly orient in the well. For short eccentrically weighted components, or for those housed within an outer housing, this one-dimensional (rotational) swivel is effective. However, for very long eccentrically weighted components that are typically installed in deviated sections of horizontal wells, the doglegs (bends) in the well will cause a bending moment across the swivel. This bending moment may cause a conventional swivel with reasonably tight clearances (or seals) to bind and not allow free rotation of the eccentrically weighted component. The eccentric weighted component provides a relatively small eccentric moment, and therefore the swivel must be able to rotate freely under a very low torque generated by eccentric weighting. An articulatingswivel is proposed, which allows free rotation despite angular misalignment of the axis, which is also advantageous to remove bending loads from the lower end of a pump and an upper end of a low-side intake. An optimal articulating swivel is a ball joint which allows for a low amount of axial movement (backlash) and a higher degree of sealability with the lowest torque, even without seal elements.

[0017] An articulating swivel is proposed that allows free rotation of an eccentrically weighted low-side intake and angular misalignment of the axes.

[0018] A flex joints or articulating swivel is proposed for use between sections of a low-side intake.

[0019] Various liner configurations with a low-side intake are proposed.

[0020] A downhole low-side intake is disclosed comprising: a wellbore liner; an intake stage with low- side oriented inlet openings uphole of a plug or bullnose; and a pump receptacle or pump connector at a downstream end of the wellbore liner.

[0021] A downhole low-side intake is disclosed installed as a liner in a wellbore in which: the liner comprises a plug or bullnose toward a downhole end, and an intake stage with low-side oriented inlet openings, and a receptacle for a pump, in which a production tubing string comprising a downhole pump is installed after the low- side intake, and the intake of the downhole pump is hydraulically coupled to the outlet of the low-side intake stage.

[0022] Related apparatuses and methods are proposed.

[0023] A low-side intake for a downhole pump is disclosed comprising: A tubular with one or more inlet openings oriented toward a low-side, the one or more inlet openings connected to feed a fluid outlet at the downstream end.

[0024] An intake is disclosed for a downhole pump comprising: an eccentrically weighted component that freely rotates to orient inlet openings toward the low-side of the wellbore, with an articulated swivel at the downstream end; the articulated swivel allows angular misalignment of the axis of the intake and the axis of the component above it.

[0025] An intake is disclosed for a downhole pump comprising: an eccentrically weighted component that freely rotates to orient inlet openings toward the low-side of the wellbore, with inlet openings of a reduced flow area to restrict flow toward the downstream end to provide a more uniform inflow profde along its length thereby improving gas avoidance efficiency and in which an eccentric weighting is provided by rolling one edge of a flat plate inside the other edge to form a tubular with an overlapping portion, with a seam weld.

[0026] A downhole low-side intake comprising a tubular, which is eccentrically weighted by having one longitudinal edge rolled inside another longitudinal edge to form an overlapping portion that is sealed together to allow rotation of the downhole low-side intake within the wellbore to align one or more inlet openings in the tubular toward a low-side of the wellbore.

[0027] An intake is disclosed for a downhole pump comprising: an eccentrically weighted component that freely rotates to orient inlet openings toward the low-side of the wellbore, in which the weighted component comprises crosswise baffles external to a tubular housing; these baffles may function to maintain standoff from the casing, to create an eccentric center of mass, and / or to affect the flow patterns in the annulus.

[0028] A downhole low-side intake is disclosed comprising: a tubular, eccentrically weighted to orient at least one row of inlet openings toward the low-side, and in which inlet openings are louvered to direct flow that passes through the inlet openings, to align with direction within the tubular.

[0029] An intake is disclosed for a downhole pump comprising: an eccentrically weighted component that freely rotates to orient inlet openings toward the low-side of the wellbore, in which the weighted component comprises telescoping tubulars of decreasing diameter toward an upstream end with crosswise external eccentric baffles.

[0030] An intake is disclosed for a downhole pump comprising: an eccentrically weighted component that freely rotates to orient inlet openings toward the low-side of the wellbore, in which the weighted component comprises a lengthwise permeable baffle external to the intake tubular and extending at least most of the length of the intake.

[0031] An intake is disclosed with multiple stages, each stage comprising a low-side inlet opening of an inner housing located downhole of openings in a permeable baffle, in which the inner and outer housings are rigidly connected, eccentrically weighted, and orient as-one in the wellbore.

[0032] An intake is disclosed with multiple stages, each stage comprising an inlet openings of an inner housing located downhole of openings in a permeable baffle, in which a swivelling eccentrically weighted baffle is located between the openings of an inner housing and permeable baffle, and the eccentrically weighted baffle orients an opening toward a low-side.

[0033] An eccentrically weighted low-side intake is disclosed with an articulating swivel that allows free rotation of an eccentrically weighted low-side intake and angular misalignment of the axes.

[0034] An intake is disclosed for a downhole pump comprising: an eccentrically weighted tubular component that freely rotates to orient inlet openings toward the low-side of the wellbore, in which the weighted component comprises two or more sections separated by a flexible joint, the flexible joint being configured to allow relative movement to cause angular misalignment between the axis of each of the two or more stages. The flexible joint may also allow independent rotation of adjacent intake stages (an articulated swivel).

[0035] A method is disclosed of landing a low-side intake assembly into a well as a liner then installing a pump intake which resides within the intake liner.

[0036] A downhole pump is disclosed comprising: a downhole pump; and a low-side intake stage or a multi-stage low-side intake located upstream of the pump intake.

[0037] A multi-stage downhole low-side intake comprising: an outer housing; a plurality of intake stages that each: are formed of a tubular within the outer housing and are separated from adjacent intake stages by external crosswise baffles; have one or more inlet openings distributed circumferentially around the tubular; and have an eccentrically weighted baffle residing within the annular space between the outer housing and the tubular that defines a baffle inlet opening and is configured to rotate relative to the tubular to orient the baffle inlet opening toward a low-side of the wellbore.

[0038] Embodiments of gas avoiders of the present disclosure provide a more uniform inflow profile along its length that improves gas avoidance effectiveness by reducing the velocity of liquid toward a low-side inlet opening below a bubble rise velocity. This velocity reduction occurs in a separation region toward a low-side, theseparation region may comprise an eccentric annulus between an intake tubular and the casing, or the separation region may comprise a space below a permeable baffle, or the separation region may comprise a space within a permeable baffle.

[0039] Embodiments of gas avoiders of the present disclosure enable a longer overall intake stage to be utilized. The length-to-housing diameter (L:D) ratio of the overall intake stage may be greater than 40: 1, by combining the eccentric weighting and the intake stage within the same stage of an intake. A high intake stage L:D ratio may be enabled by an articulated swivel that allows for more than one degree of freedom, to reduce bending forces within the swivel, pump, and the intake stage that may otherwise be caused by doglegs in the wellbore. A large number of low-side dip tube stages may be economically achieved using in each stage swivelling eccentrically weighted baffles.

[0040] While the simplest use cases of many of the embodiments claimed may be in pumps with an intake at a downhole end such as SRP and PCPs, it should be interpreted to be applicable to any downhole pump including: ESPs with a shroud over the motor section, vane pumps, twin screw pumps, hydraulic rotary pumps, hydraulic positive displacement pumps, jet pumps, gas driven positive displacement pumps, etc. With certain liner type installations, it may not be necessary for a pump to have an intake located, or relocated with a shroud, to a downhole end.

[0041] While the main use case may be in horizontal wells with the pump intake installed in a portion of the wellbore with an inclination between 70° and 92°, and with the intake located uphole of the perforated section of the wellbore, the applications may also extend to deviated wells, pump intakes installed in a portion of the wellbore with an inclination between 45° and 70°, and wells where the pump intake is installed within the perforated section of the wellbore.

[0042] Embodiments of intakes of the present disclosure improve the efficiency and reliability of pumping a gas laden fluid, for example, one or more downhole fluids associated with a hydrocarbon recovery or production operation. It is designed to ingest and process larger total volumes of fluid while allowing larger total volumes of gas to be vented past the pump up the casing annulus in order to provide higher levels of drawdown and production, while improving reliability and efficiency of the pump.

[0043] Illustrative embodiments of the present disclosure are described in detail herein. In the interest of clarity, not all features of an actual implementation may be described. It will of course be appreciated that in the development of any such actual embodiment, numerous implementation-specific changes will be made to achieve the specific implementation goals, and will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of the present disclosure.

[0044] In various embodiments, there may be included any one or more of the following features: The one or more inlet openings decrease in size toward the downstream end. The one or more inlet openings comprise plural inlet openings that are uphole of and spaced in relatively close proximity to an external crosswise baffle. An inlet section defines the inlet openings, with the inlet section having an inlet section length to outside tubular diameter ratio of greater than 10:1. The one or more inlet openings are structured to relatively progressively increase a restriction to intake flow, through the inlet openings, toward the downstream end. The inlet openings are structuredto equalize inflow along a longitudinal length of an inlet section of the downhole low-side intake that defines the inlet openings. The inlet openings are one or more of shaped, patterned, or arranged to progressively decrease intake flow area per longitudinal unit length toward the downstream end. The tubular is eccentrically weighted by having one longitudinal edge rolled inside another longitudinal edge to form an overlapping portion that is sealed together. An exterior low-side profile of the overlapping portion is shaped to define a larger radius than an average radius of the tubular. The inlet opening comprise two or more rows of inlet openings along a longitudinal length of the downhole low-side intake, with each row at or adjacent a respective longitudinal edge of the overlapping portion. A swivel is at or adjacent the downstream end. A swivel is downstream of the tubular and about which the tubular is eccentrically weighted to rotate within the wellbore. The swivel is configured to articulate. The swivel is configured to allow relative movement to cause an angular or parallel misalignment of axes of the tubular and an uphole portion of the swivel. A pump intake is coupled in an uphole direction to the swivel. The tubular comprises a pump motor shroud coupled to an uphole end of the swivel to define the downstream end of the downhole low-side intake. The tubular comprises a liner coupled to the swivel. The swivel comprises a flexible connection. A flexible connection is downstream of at least a section of the tubular and is connected to rotate together with the tubular within the wellbore. The flexible connection or swivel comprises a plurality of tubular housings that are one or more of nested or linked together to pivot. The flexible connection is one or more of: at or adjacent the downstream end; and between plural intake stages of the downhole low-side intake. The flexible connection comprises a flex joint that is configured to allow relative movement to cause angular or parallel misalignment of axes of adjacent intake stages, of the downhole low-side intake, upstream and downstream of the flexible connection without allowing relative rotation of upstream and downstream ends of the flex joint. The flex joint is non-sealing. An external crosswise baffle is located within close proximity in a downhole direction from the flex joint. The external baffle comprises a lengthwise baffle. The lengthwise baffle at least partially encircles the tubular. The lengthwise baffle comprises a permeable portion. The flexible connection comprises a flex joint that is configured to not seal, and in which a crosswise baffle is located within close proximity in downhole direction from the flex joint, and a non-permeable portion of a lengthwise baffle covers a high-side above the flex joint. The flex joint is non-sealing; an external crosswise baffle is located within close proximity in a downhole direction from the flex joint; and a non-permeable portion of an external lengthwise baffle covers a high-side of the flex joint. A non-permeable portion of the lengthwise baffle covers a high-side of the flex joint. The swivel comprises a plurality of tubular housings that are one or more of nested or linked together to pivot. The swivel comprises a ball joint. The crosswise baffle comprises a closed bullnose at an upstream end of the downhole low-side intake. The bullnose comprises a drain hole. The bullnose comprises a removeable drain plug. The inlet openings are louvered to direct flow that passes through the inlet openings to align with an axis of the tubular. Inlet openings are louvered via a punching process. Louvered inlet openings are formed inwards in a square or rectangular tube and direct the flow towards a comer or a side wall of the flowpath within the tubular and in a direction that is aligned with flow in the tubular. The inlet openings that are louvered are punched outwards and have a rounded surface on an inner downstream edge. The intake has an external lengthwise baffle. The tubular comprises an inner housing that is rigidly coupled to the lengthwise baffle. The external lengthwise baffle comprises an eccentric external lengthwise baffle. The lengthwise baffle has a permeable portion. The inlet openings define an inlet section, and the permeable portion extends a longitudinal length of the inlet section. The permeable portion is supported eccentrically over the tubular by eccentric crosswisebaffles. The lengthwise baffle comprises a non-permeable portion adjacent to the inlet openings of the tubular. Inlet openings are located in close proximity in a downstream direction of the crosswise baffle. The permeable portion is structured to, in operation, isolates turbulent and gassy wellbore flow from low-side liquid gathering space (in some embodiments a separation chamber) below the permeable portion. The permeable portion comprises a perforated panel. The lengthwise baffle comprises a shroud that at least partially encircles the tubular and is configured to hook via tabs to the tubular and / or to crosswise baffles. The external baffles are configured to one or more of: maintain a standoff from a well casing; define an eccentric center of mass to eccentrically weight the tubular; or direct flow patterns around the downhole low-side intake and the inlet openings. The external baffles comprise a plurality of eccentric external baffles spaced in a longitudinal direction along the downhole low-side intake. The plurality of eccentric external baffles comprise crosswise baffles. The plurality of eccentric external baffles comprise a plurality of tubular outer housings or lengthwise baffles. The plurality of eccentric external baffles comprises crosswise baffle plates oriented transverse to an axis of the tubular. The tubular has a varying diameter along a longitudinal length of the tubular. The tubular is formed of plural inner housings of different diameters. The external baffle comprises an eccentric crosswise baffle located at a junction between the inner housings of the tubular, the inner housings having different diameters. The external baffle comprises a plurality of external baffles; and the tubular forms an inner housing and the external baffle forms an outer housing, which is rigidly connected to the inner housing. The downhole low-side intake is formed of two or more intake stages connected end-to-end. Each intake stage is bounded by an external baffle of the plurality of external baffles at an uphole end and a downhole end of the intake stage. For each stage: the inlet openings comprise low-side oriented inlet openings that are located toward a downhole end of the intake stage, and the outer housing has at least one opening to make it permeable, with the at least one opening being located toward an uphole end of the intake stage. Fluid flow paths of the intake stages connect in parallel to collectively pass fluids from the intake stages downstream through the tubular. The lengthwise baffle comprises a plurality of tubular outer housings. The external baffle comprises a crosswise baffle. An inner eccentric weighted baffle rotates relative to a tubular and external baffle to low-side-orient an opening of the inner baffle to substantially cover inlet openings of the tubular and permits radial flow into the inlet openings of the tubular. The inner eccentric weighted baffle low-side-oriented opening permits axial flow in a downhole direction within an annulus between the tubular and the outer housing. A rotatable thru-shaft part extends between downstream and upstream ends of the downhole low-side intake. One or more impellers are between adjacent intake stages, and that are structured to convey fluid from a separation chamber of each intake stage into an inner common fluid flow path of the intake stage, the inner common fluid flow path defined by the tubular. The inlet opening from a separation chamber into the inner common fluid flow path may be substantially axial in nature, and in close proximity to an impeller. The inner common fluid flow path may comprise sections of diffusers, couplers, shaft support bearings, and tubular sleeves, typically axially compressed within an outer housing. The inner housing and outer housing are arranged concentrically relative to one another. The downhole low-side intake is installed as or coupled to a liner in a wellbore. The liner defines a liner receptacle that defines a bore. A pump intake is coupled in an uphole direction of the downhole low-side intake. A pump motor shroud is coupled in an uphole direction of the downhole low-side intake. A production tubing string is installed, with a pump intake of a downhole pump hydraulically coupled to an outlet of the downhole end of the liner. A packoff is installed in the bore to provide a hydraulic coupling. A non-sealing restriction is achieved at a packoff between the production string and the liner ofthe downhole low-side intake. A packoff is located above the pump intake. An intake stage of the downhole low- side intake is downhole of the pump intake. Flow inside the downhole low-side intake is primarily in an uphole direction. A packoff is located below the pump intake. An intake stage of the downhole low-side intake is uphole of the pump intake. Flow inside the downhole low-side intake is primarily in a downhole direction. Intake stages of the downhole low-side intake are both downhole and uphole of the pump intake. The downhole low-side intake is configured such that flow inside portions of the downhole low-side intake is in a downhole direction and flow inside other portions of the low-side intake is in an uphole direction. An intake stage of the downhole low-side intake is oriented manually during installation, the orientation being measured during the installation process. A pump receptacle is present, in which a production tubing string comprising a downhole pump is installed in the wellbore, with an intake of the downhole pump hydraulically coupled to an outlet of the downhole low-side intake. A liner comprising the downhole low-side intake. A production string comprising the downhole low-side intake. A multistage downhole low-side intake for a downhole rotary pump comprising a plurality of the downhole low-side intakes coupled together. Using the downhole low-side intake to produce fluids from a wellbore. The downhole low-side intake is installed at an inclination between 45 and 100 degrees. The low-side intake is structured to relatively progressively increase a restriction to intake flow, through the inlet openings, toward the downstream end. The low- side intake is structured to relatively progressively increase the restriction to intake flow to equalize inflow along an axial length of the inlet openings. The inlet openings are one or more of shaped, patterned, or arranged to progressively decrease intake flow area per axial unit length toward the downstream end. A ratio of decreasing intake flow area per axial unit length is greater than 2:1. An intake may have a length to outside tubular diameter ratio of greater than 10:1. The inlet openings each comprise a hole, slot, tapered slot, or punched louvered opening. The eccentrically weighted part has a tubular housing or inner tubular housing that is hollow and defines a fluid flow path to the fluid outlet. The inlet openings are defined through a wall of the tubular housing. An intake part of the low-side intake defines the inlet openings. A ratio of the overall length of the intake part to an outer diameter of the tubular housing is greater than 20:1. An eccentrically weighted tubular of a low-side intake with one edge rolled inside the other to form an overlapping portion. An eccentrically weighted tubular may comprise a higher radius portion its exterior profile toward a low-side. The diameter of the low-side intake decreases in diameter from a larger diameter upper end to a smaller diameter lower end. The diameter may decrease gradually - a tapered tube. The diameter may decrease at a step between tubes of different diameters. A baffle external to a tubular housing, such as the crosswise baffle, functions to maintain standoff from the casing, to define or create an eccentric center of mass to eccentrically weight the tubular, and / or to affect, for example direct, the flow patterns around the downhole low-side intake and the inlet openings, for example in the annulus. The crosswise baffle comprises a plurality of eccentric crosswise baffles spaced in a longitudinal direction along the downhole low-side intake. The plurality of eccentric crosswise baffles comprises crosswise baffles at an upstream end and the downstream end of the downhole low-side intake. The plurality of eccentric crosswise baffles comprise baffle plates oriented transverse to an axis of the tubular. The tubular has a varying diameter along a longitudinal length of the tubular. The tubular is formed of plural inner housings of different diameters. The external baffle comprises an eccentric crosswise baffle located at a junction between the inner housings of different diameters. External baffles may comprise eccentric rings with a diameter larger than a tubular housing. External baffles may comprise a higher radius portion of their outer profile toward a low-side. A permeable lengthwise baffle external to the intake tubular and extending at least most of thelength of the intake stage separates a path for gas and slugs to pass over the high-side of the intake while maintaining a low-turbulence liquid zone toward the low-side of the annulus. A low-side intake where a non- permeable portion of an outer housing spans an axial position adjacent to low-side inlet openings of an inner housing, where the inner and outer housings are rigidly connected and orient as-one in the wellbore. A low-side intake where a non-permeable portion of an outer housing spans an axial position adjacent to low-side inlet openings of an inner housing, and where a swivelling eccentrically weighted baffle orients an opening toward a low- side. A stage of a low-side intake with a crosswise baffle comprising a low-side inlet opening. A stage of a low-side intake with a secondary weir crosswise baffle comprising a high-side opening. A stage of a low-side intake with a crosswise baffle comprising a low-side inlet opening defining a separation chamber for gas at the upstream end and a separation chamber for solids at the downstream end. A stage of a low-side intake with a separation chamber for solids with a strainer or filter located within it. A stage of a low-side intake with a separation chamber for solids with a lengthwise strainer or filter located within it defining a channel for filtered fluids to an inlet opening of an inner housing. The tubular comprises low-side inlet openings. A crosswise baffle is present and comprises low-side inlet openings. The external lengthwise baffle fully encircles the tubular, and a gas separation chamber is defined between a permeable portion of the external lengthwise baffle and the crosswise baffle with low-side inlet openings. A solids separation chamber is defined between the crosswise baffle with low-side inlet openings and the external crosswise baffle, which is at the downhole end of an intake stage of the downhole low-side intake. A strainer or filter is within the solids separation chamber. A crosswise baffle with a high-side opening is within the solids separation chamber. Inlet openings of a tubular are high-side within the solids separation chamber. An articulating swivel of an eccentrically weighted low-side intake. Flex joints, articulation joints, or swivels are located between stages of the low-side intake and allow the intake to orient correctly and to sit low-side over an extended length (e.g. >9m), despite doglegs and complex wellbore trajectories. The swivel is configured to cause a non-zero distance of misalignment between an axis of an inner housing of the low-side intake and an axis of an overlapping portion of the swivel. A method of landing a low-side intake assembly into a well as a liner then installing a pump intake that resides within the intake liner; a packoff may seal between a production tubing or pump and the liner receptacle; or a packoff may restrict flow between the production tubing and the intake liner; or a packoff may not be required. A liner configuration for use with ESPs (which require a flow path directly past the motor for cooling) avoids the need to handle a shroud each time the ESP is replaced. A liner configuration may also be preferred for long or complex intake assemblies to avoid the need to re-install the intake device every time the production string is removed from the well. A plug or bullnose is toward or at a downhole end of the wellbore liner. The intake comprises a tubular, which is eccentrically weighted by having one longitudinal edge rolled inside another longitudinal edge to form an overlapping portion that is sealed together to allow rotation of the downhole low-side intake within the wellbore to align inlet openings in the tubular toward a low-side of the wellbore. For one or more of the plurality of intake stages, the eccentrically weighted baffle is configured to substantially cover the inlet openings of the tubular and permit flow into a low-side-oriented inlet opening, or portion thereof, of the inlet openings of the tubular. For one or more of the plurality of intake stages, the tubular and the outer housing are arranged concentrically relative to one another. For one or more of the plurality of intake stages, the low-side-oriented inlet opening is oriented to permit axial flow in a downhole direction within an annulus between the tubular and the outer housing. An inner eccentric weighted baffle comprises low-side inlet openings and a low-side strainer or filter. Fluid flow paths of the intakestages connect in parallel to collectively pass fluids from the intake stages downstream. A rotatable thru-shaft part extends between downstream and upstream ends of the multi-stage downhole low-side intake. For one or more of the plurality of intake stages, the intake stage comprises one or more impellers that are structured to convey fluid from a separation chamber of the intake stage into an inner common fluid flow- path of the intake stage, the inner common fluid flow path being defined by the tubular For one or more of the plurality of intake stages, tire intake stage comprises a strainer or filter within tire separ ation chamber. Inlet openings define a strainer or filter, or in which a strainer or filter is coupled to the eccentrically weighted baffle. An annular gas separation chamber is defined between the permeable portion of the outer housing and tire eccentrically weighted baffle and a strainer or filter is within the gas separation chamber.

[0045] The foregoing summary is not intended to summarize each potential embodiment or every aspect of the subject matter of the present disclosure. These and other aspects of the device and method are set out in the claims.BRIEF DESCRIPTION OF TI IE FIGURES

[0046] Embodiments will now be described w'ith reference to the figures, in which like reference char acters denote like elements, by way of example, and in which: Fig. 1 A is a side elevation view of a low-side intake disposed below a pump, on the end of a production tubing string in a wellbore that penetrates an underground formation substantially horizontally. Fig. IB is a cross-section view, taken along the IB section lines of Fig. 1 A, of a wellbore through a low-side oriented intake with a fluid level showing vertical velocity vectors of the liquid and gas. Fig. 1C is a side elevation view of a long low-side intake in a curved portion of the wellbore. Fig. ID is a side elevation view of a long low-side intake comprising an articulated swivel and a flex joint between multiple stages the same curved wellbore Fig. IE is a side elevation view of an intake installed as a liner in a wellbore. Fig. IF is a side elevation view of an intake installed as a liner with a retrievable plug, a hanger at the upper end with a perforated portion. Fig. 1G is a side elevation view of an intake installed as a liner with a retrievable plug, a hanger at the lower end with a perforated portion. Fig. 1H is a side elevation view of an intake installed as a liner with inlet openings positioned above an ESP intake. Fig. 11 is a side elevation view of intakes installed as a liner positioned above and below an ESP intake and no packoff. Fig. 1 J is a side elevation view of an intake installed below an ESP with a motor shroud and a parallel tubular. Fig. IK is a side elevation view of an intake installed above an ESP with a shroud comprising a low-side intake. Fig. 2 is a side elevation view of an embodiment of a low-side intake device with external baffles. Fig. 3A is a cross-section view of an intake device taken along the 3A section lines of Fig. 2. Fig. 3B is a cross-section view of an intake device taken along the 3B section lines of Fig. 2. Fig. 3C is a crosssection view of an alternative embodiment of a low-side intake device with an eccentric weighted cross-section. Fig. 3D is a cross-section view of an embodiment of an intake device with an alternate eccentric weighted cross-section. Fig. 3E is a cross-section view of an embodiment of an intake device with an alternate eccentric weighted crosssection. Fig. 3F is a cross-section view of an embodiment of an intake device with an alternate eccentric weighted cross-section. Fig. 4A is a side elevation view of an embodiment of an intake device that telescopes in size without a step. Fig. 4B is a perspective view of an embodiment of an intake device with an external baffle comprising a midbody centralization ring. Fig. 4C is a side perspective view of an embodiment of an intake device with mid-body centralization rings at a junction between inlet sections with varying diameter. Fig. 5 A is a perspective view of anembodiment of an intake device with permeable baffle external to the intake tubular and extending at least most of the length of the intake. Fig. 5B is a cross-section view, taken along the 5B section lines of Fig. 5A, including the casing, which was not shown in Fig. 5A. Fig. 6A is a cross-section view similar to Fig. 5B showing an alternative embodiment in which the permeable baffle is curved in an elliptical shape. Fig. 6B is a cross-section view similar to Fig. 6A showing an alternative embodiment in which the permeable baffle is a complete tube. Fig. 6C is a crosssection view similar to Fig. 6B showing an alternative embodiment in which the inner housing has a rectangular tubular section, and a permeable baffle has a non-permeable portion over inlet openings. Fig. 7A is a bottom plan view of a portion of an intake device similar to Fig. 6A with a permeable baffle having continuous permeable portion and regularly spaced inlet openings. Fig. 7B is a bottom plan view of a portion of an intake device similar to Fig. 7A with inlet openings spaced uphole from crosswise baffles in relatively close proximity. Fig. 7C is a longitudinal cross-section view cut external to the inner housing of a portion of an intake device similar to Fig. 7B showing a liquid level in the annulus external to an inner housing. Fig. 7D is a bottom plan view of a portion of an intake device similar to Fig. 7B with an impermeable portion of the permeable baffle spaced relatively to cover over inlet openings. Fig. 7E is a longitudinal cross-section view cut external to the inner housing of a portion of an intake device similar to Fig. 7D showing a liquid level in the annulus external to an inner housing. Fig. 8A is a crosssection view similar to Fig. 6A showing an alternative embodiment in which external baffles and bullnose comprise a slot for a parallel string. Fig. 8B is a detail cross-section view, from the 8B detail area denoted by a dashed circle in Fig. 8A, of a junction between a crosswise baffle and a lengthwise baffle. Fig. 8C is a cross-section view similar to Fig. 8A showing an alternative embodiment in which a permeable baffle is a polygonal shape. Fig. 9A is a perspective cutaway view of a distal end of an intake device illustrating a bullnose, spiral centralizer, and a parallel string. Fig. 9B is a perspective cutaway view of a stage of an intake device illustrating features that may be incorporated by sheet metal fabrication techniques. Fig. 9C is a perspective cutaway base view of the lower side of the stage of Fig. 9B. Fig. 9D is a perspective cutaway view of a stage of an embodiment of an intake device illustrating sheet metal assembly features. Fig. 9E is an end view of a crosswise baffle with sheet metal assembly features. Fig. 9F is a perspective cutaway view of a stage of an alternate embodiment of an intake device. Fig. 9G is a perspective wireframe / transparent view of multiple stages of an intake device with a discontinuous permeable baffle comprising discrete sections. Fig. 9H is a perspective wireframe / transparent view of multiple stages of an intake device with a tubular permeable baffle comprising a single opening of each stage. Fig. 91 is a side / transparent view of a stage of an alternate embodiment of an intake device. Fig. 9J is a perspective view inside the separation chambers of an intake device with a strainer. Fig. 9K is a perspective view inside the separation chambers of an alternate embodiment of an intake device with a strainer. Fig. 9L is a perspective view inside the separation chambers of an alternate embodiment of an intake device with a strainer. Fig. 9M is a perspective longitudinally cut view of an alternate embodiment of an intake device. Fig. 10A is a longitudinal cross-section view of a swivel that allows rotation and angular misalignment of the axis of the intake with the component above, and a distance of misalignment between the swivel and tubular below. Fig. 1 OB is a perspective longitudinally cut view of a ball-joint swivel that allows rotation and angular misalignment of the axis of the intake with the component above. Fig. 11A is a perspective view of an embodiment of a flexible joint between two tubular members that allows articulation (angular misalignment of the axis of adjacent tubular members) without allowing independent rotation. Fig. 1 IB is a longitudinal cross-section view of Fig. 11 A. Fig. 11C is a perspective view of an alternative embodiment of atubular link with elongated holes for link pins. Fig. 1 ID is a is a longitudinal cross-section view similar to Fig. 11 A with a straight link. Fig. 1 IE is a longitudinal cross-section view of a flex joint with rectangular section tubulars, and a non-permeable portion of a permeable baffle covering the flex joint, axes of the tubular components are misaligned by both an angle and a distance. Fig. 1 IF is a perspective wireframe view of the flex joint of Fig. 1 IE. Fig. 11G is a perspective longitudinally cut view of a flex joint of an intake apparatus having an eccentric lengthwise baffle with a non-permeable portion extending in an uphole direction to cover the flex joint. Fig. 11H is a perspective longitudinally cut view of an alternate embodiment of a louvered inlet opening. Fig. 12A is a longitudinal cross-section view of a multistage intake apparatus with a swivelling eccentrically weighted baffle. Fig. 12B is a perspective view of an embodiment of an inner eccentric weighted baffle. Fig. 12C is a perspective longitudinally cut view of an alternate embodiment of an inner eccentric weighted baffle. Fig. 13A is a longitudinal cross-section view of a multistage intake apparatus with a swivelling eccentrically weighted baffle and an impeller. Fig. 13B is a perspective detail view of a portion of a stage of Fig 13A, with the lengthwise baffle hidden. Fig. 13C is a perspective view an inner eccentric weighted baffle with a strainer.DETAILED DESCRIPTION

[0047] Immaterial modifications may be made to the embodiments described here without departing from what is covered by the claims. In the claims, the word “comprising” is used in its inclusive sense and does not exclude other elements being present. The indefinite articles “a” and “an” before a claim feature do not exclude more than one of the feature being present. Each one of the individual features described here may be used in one or more embodiments and is not, by virtue only of being described here, to be construed as essential to all embodiments as defined by the claims. Features and their benefits are only discussed in detail for the first figure for which they are shown. In general, the complexity of embodiments increases sequentially through the Figs, and for the sake of clarity and brevity. In order to understand the configuration and benefits of features shown in certain figures, it may be necessary to read the entire description to that point and applying the understanding of features, configurations, and benefits from previous Figs, into the reading of subsequent figures.

[0048] The terms “couple” or “couples,” as used herein are intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection such as a shaft, flange or weld connection, or through an indirect electrical or fluid connection or coupling via other devices and connections.

[0049] The term “rigid” or “rigidly” refers to a connection that does not in use allow independent rotation of connected components. In other contexts, it is also used to refer to a connection that does not in use allow angular or a distance of misalignment of the axes of connected components.

[0050] The term “fluid” is used to refer to generally liquids or gasses or mixtures thereof.

[0051] The term “liquid” refers to a fluid which is primarily, or primarily intended, to be composed of liquid and typically includes the presence of some gas which may be dissolved or entrained in the liquid as bubbles.

[0052] The term “gas” refers to a fluid which is primarily, or primarily intended, to be composed of gas and typically includes the presence of some liquid which may be carried with the gas as mist, droplets, foam, a film, or even as slugs or waves. Gas may be wet, and for thermal operations may be primarily composed of water vapor (steam) or solvent vapor.

[0053] The term “uphole” is used to refer to the downstream location relative to fluid flow within the pump, corresponding to the direction that fluids are pumped up and out of the wellbore. Correspondingly “downhole” refers to the upstream location relative to fluid flow within the pump, regardless of the horizontal or vertical orientation of the device or wellbore.

[0054] The term “upper”, or “top” is used to refer to the orientation relative to gravity within a substantially horizontal wellbore, corresponding to the direction that gas will naturally separate or stratify within a substantially horizontal wellbore. Correspondingly “bottom”, or “lower” refers to the orientation relative to gravity within a substantially horizontal wellbore, corresponding to the direction that liquids will naturally separate or stratify within a substantially horizontal wellbore.

[0055] The term “tubular” refers to any elongate hollow structure used in a production tubing string, or an intake device. Typically, tubulars are cylindrical, with a slight ovality and variations in wall thickness. For the present disclosure a broader definition is used where any hollow section may comprise a tubular, including sections with ovality, or comers (e.g. polygonal cylindrical shapes), or variations in wall thickness.

[0056] The term “liner” refers to any string of tubulars that is installed in a well that does not extend to the wellhead (surface). Liners are typically hung from a liner hanger to prevent movement in a well, and may optionally be sealed at an upper end; but in horizontal wells, a liner may simply be ‘dropped off in the well or ‘set on bottom’ where gravity keeps the liner approximately in the desired position in the well.

[0057] The term “annulus” refers to the space between a production casing and a production tubing or pump or intake device.

[0058] The intake of the present disclosure may be used with any downhole pump and associated downhole motors, if present. Some figures show pumps with motors, and others do not; this is not intended to be limiting but to illustrate the various options. Some figures may not show or illustrate the adjacent components or the details of the couplers that would couple to the adjacent components.

[0059] The present disclosure relates generally to the separation of gas and liquid phases of downhole fluids at the intake of a downhole pump and more particularly to an intake and gas separator system to maximize pump efficiency and potential drawdown, especially in gassy wellbores with high flow rates, and high deviation or horizontal wellbores with unstable flow regimes.

[0060] In gravity-based separators, bubbles rise in an upward direction while liquid preferentially flows in a downward direction - gravity is a primary mechanism by which gas separates. Gravity-based separators may be separated into two classes, which may be selected between depending on the inclination at which they are used. Typically, for non-horizontal inclination applications e.g., between 0 degrees inclination (vertical) and 88 degrees inclination, they may reverse the flow direction of the flow which limits the amount of gas that can flow in a downhole direction through a flow path - these may be known as reverse-flow separators, dip tubes, liquid concentrating intakes and other names. The other class of gravity-based separators known as gas avoiders or low- side intakes; and are typically used in substantially horizontal applications (e.g., typically greater than 60 degrees inclination). Gas avoiders operate based on the principle of gravity-based segregation of phases in stratifying within a cross-section of the wellbore, rather than axially along the length of a wellbore. The flow regimes in wellbores may include stratified, chum, and slug flow. Most prior art low-side intakes are substantially less effective in chumand slug flow and at high flow rates due to their short length, and their exposure to turbulence and slug flow within the wellbore. Because of the strong transient pressure gradients within the flow in the wellbore the vertical component of the velocity in the wellbore adjacent to a gas avoider intake must be relatively low to function effectively. Gas avoiders rely on the buoyancy of gas bubbles to rise in the opposite direction that liquid is flowing, therefore the velocity in the low-side of the wellbore (where gas separation is occurring) must be below the bubble rise velocity. Velocity of bubbles is the subject of various studies, and larger bubbles rise faster and are more easily avoided. Very small bubbles and entrained gas and foam may be practically impossible to avoid or separate. A typical rule of thumb accepted by industry for sizing dip-tube style gravity-based separators may be a liquid velocity of approximately 6 inches / second for ‘A” bubble sizes, although lower liquid vertical velocity rules of thumb as low as 1 inch / second have been proposed. When slug flow occurs in an eccentric annulus, which is typical of an annulus adjacent to a gas-avoider intake, it can be observed that the liquid level toward the low-side of the casing is very persistent, and even in severe-slug flow conditions when a slug of gas passes along the high-side of the casing, the liquid from the lower part of this eccentric annulus is not displaced by gas; however, the liquid capacity in this lower annular space is very small and a short intake with a typical production rate will consume this liquid and suck in gas before a gas slug has finished passing the intake. Because the volume capacity of the lower portion of the eccentric annulus is relatively small, the use of a long intake device that distributes inflow over its length can improve performance. Longer is better, however there is a practical limit to the length of an intake stage. Typically, logistics and rig handling of any item over 14m in length is inefficient when working with typical oilfield equipment. Another limit to length is flowing friction pressure within the intake - because the intake is a passive device, it relies on the suction pressure of the pump, and applying a substantial pressure drop (restriction) upstream of the pump intake is detrimental to pump performance and may cause secondary issues such as scaling or gas breakout. A further limitation to the length of an eccentrically weighted intake is the stiffness of the assembly which is installed in horizontal wells with doglegs, which can become a problem if a portion of the intake sits substantially above the low-side of the casing because of the curvature of the casing, or can become a problem if the low-side intake does not automatically orient correctly because of the bends in the casing. Typical wellbore doglegs where a pump and intake are intentionally installed may be in the order of 0 to 4 degrees per thirty meters (° / 30m), however if an extended length intake is installed, it may extend into a portion of the wellbore below the planned ‘pump tangent’ where doglegs may be in excess of 15° / 30m. Articulation joints or swivels located between stages of the low-side intake allow the intake to orient correctly and to sit low-side over an extended length (e.g. >9m), despite doglegs and complex wellbore trajectories.

[0061] A long and eccentrically weighted low-side intake with a tapered hole pattern is proposed in US. Pat. No: 11060389. It discloses methods allowing access to the wellbore by easily retrieving the intake or bypassing tools through the intake.

[0062] A dip tube type gas separator on the end of a production tubing string with a retrievable plug is proposed in US. Pat. No: 11008847. It also considers orientation of the openings in an outer housing with small holes at a high-side for gas exhaust, but it does not contemplate orienting the inlet openings of an inner housing.

[0063] An intake showing a tapered hole pattern with a porous structure is proposed in US. Pat. No: 10260330. Two structures (such as a permeable baffle and an inner housing) with a low-turbulence space between them for gas separation to occur in horizontal wells is not considered.

[0064] A multi-stage gravity-based gas separator is proposed in U.S. Pat. No. 11,131,180 with multiple stages arranged in parallel. It did not include low-side intakes. In order to obtain contribution from the lower stages of the separator, a limited-entry port disposed on the inner tube (inner housing), which may be located toward the downhole end of each separation stage where the size of said port increases in upstream stages (to offset the friction pressure drop for fluid flowing up the inner housing). The inner tube (inner housing) is rigidly connected to the outer tube (permeable baffle). This disclosure did not contemplate the use of eccentrically weighted components or eccentric weighting of the intake assembly for optimal function at substantially horizontal inclination. Additionally, the sealed nature of each stage is relatively expensive to manufacture, and may reduce the practicality of economical manufacture and use of a separator with for example more than 10 or more than 20 stages. A similar apparatus is proposed earlier in US. Pat. No: US4515608A, without a tapered pattern of inlet openings in the inner housing, and a stinger of unexplained function is also present.

[0065] A multistage intake with many short stages is proposed in US. Pat. No: 2104339. This 1933 disclosure has stage lengths that are so small that turbulence from wellbore flow would be likely disrupt gas separation that is intended to occur within a stage. It did not consider application in horizontal wells, a low-side orientation of inlet openings, nor a tapered pattern of inlet openings, nor a long apparatus with a high L:D ratio. A similar disclosure is proposed in US. Pat. Appl. No: 20170151510.

[0066] Other multistage dip-tube style intakes are proposed in US. Pat. No: 4241788, US. Pat. No: 5389128, US. Pat. No: 1655817 and US. Pat. No: 11492888. Use in inclined wellbores, or low-side / eccentric orientation of inlet openings is not considered.

[0067] Complicated apparatuses for opening low-side inlet openings are proposed in US. Pat. No:7921908 and US. Pat. No: 7980314.

[0068] A low-side intake apparatus with a weighted component that rotates relative to an outer permeable housing in which inlet openings are located downhole of openings of the permeable housing are proposed in US. Pat. No: 10443369

[0069] A low-side intake apparatus for non-downhole use is proposed in US. Pat. No: 11391140.

[0070] A low-side intake apparatus for liquid-liquid separation of water and oil phases in a downhole application is proposed in US. Pat. No: 6277286. Tapered and oriented inlet openings are considered.Decentralization of an inner housing is not considered. The high-side separating fluid (oil or gas) is produced up a production tubing instead of being vented up a casing by production tubing annulus. A similar liquid-liquid separator is proposed in US. Pat. No: 6868907, and further includes a means of orientation in which a guide device is mated with another device in the well which has a known and fixed orientation. Another similar liquid-liquid separator is proposed in US. Pat. No: US6547005 in which inlet flow to the apparatus is through a central tubular, with water-drain holes oriented toward a low-side with water being collected in an annulus external to the apparatus. Another liquid-liquid separator is proposed in US. Pat. No: 6755978, primarily focused on downhole separation and reinjection of water, the inlet flow to the apparatus is through a central tubular with multiple stage of separation foruse in an inclined wellbore; an artificial lift pump to produce liquids to surface is not considered - instead a rejecting pump is used to re-inject water. Another liquid-liquid separator is proposed in PCT. Pat. Appl. No: 2003062597, which comprises long water and oil offtake tubes having multiple openings; it proposes multiple stages in parallel with little baffles at the inlet so that stratifying and separating flow can bypass the inlet which would otherwise be so turbulent that it would not allow separation to occur past the inlets.

[0071] A decentralized dip-tube style separator is proposed in US. Pat. No: 5653286, having an outer housing (permeable baffle) with openings on both a large side and a side that is pressed up against a casing. More holes are pressed up against a casing side where the concentration of liquid is higher in a casing. An inclined or horizontal wellbore is considered, and low-side / stratified flow is not considered or taught. Orientation of the device to locate the openings toward a low-side is not considered, and the oriented openings are in an outer housing, not in an inner housing. A swivel is not considered which is further evidence that a high inclination well application was not considered.

[0072] A clever low-cost low-side intake apparatus is proposed in US. Pat. No: 2748719.

[0073] A long low-side intake apparatus with an outer permeable baffle comprising a screen or perforated tube is proposed in US. Pat. No: 10883354. This proposal does not rigidly connect the inner housing to the permeable baffle, but rather has the inner housing “flop” to a low-side within the permeable baffle. The inner housing does not comprise low-side inlets; rather inlet openings cover the entire perimeter of the inner housing and no other methods are proposed for how to block the inlet openings at the high-side of the inner housing. It does not consider a swivel. It does not consider a tapered pattern of inlet openings to provide a uniform profde of influx to an inner housing.

[0074] Horizontal separators and slug catchers are used in non-downhole applications, with horizontal permeable baffles or ribs to reduce turbulence, such as those proposed in US. Pat. No: 2728457, US. Pat. No: 5232475. A similar concept is proposed in US. Pat. No: 10583373.

[0075] A low-angle inclined separator vessel for non-downhole applications is proposed in US. Pat. No: 5837152.

[0076] A dip tube style gas separator with a tapered hole pattern seeking to provide a more uniform inflow profile through the outer housing is disclosed in U.S. Pat. No. 10,267,135.

[0077] Eccentric external collars (baffles) are proposed to orient phased / oriented perforating guns, to a high-side or a low-side or away from external lines of a casing string as may be desired in oriented perforating operations, as proposed in U.S. Pat. No. 9903185 Figs 6 and 7. At the time of writing, this technology is not commonly used or known to most wireline perforating experts, and would certainly not be common knowledge to an artificial lift specialist that may be designing downhole gas separation devices.

[0078] A dip-tube style separator is proposed in U.S. Pat. No. US2748719A, with valving at the top inlet / outlet includes a rigidly connected inner tube within the outer housing and a permeable baffle dividing two sides within the outer housing. Application within a high inclination or horizontal portion of a wellbore is not considered, nor is orientation of the inner housing or inlet openings of an inner housing toward a low-side.

[0079] A liner comprising a velocity string with a receptacle for an ESP to function as a gas separation shroud is disclosed in U.S. Pat. No. 5154588.

[0080] A liner comprising a shroud type gas separator and a packoff disposed on an ESP assembly between a motor and an intake stage is proposed in U.S. Pat. Appl. No. 2015 / 0101794. Various liner hanging and sealing methods are considered, including perforated sections above a motor so flow in the uphole direction goes through the liner lower portion for motor cooling.

[0081] A liner that directs flow into a wellbore annulus above a pump intake is proposed in U.S. Pat. No: 7174959. The liner is eccentric to a production tubular. A similar configuration is proposed in U.S. Pat. No. 9869164, U.S. Pat. No. 9869164, and U.S. Pat. No. 6039121.

[0082] A liner or liner extension with a bi-duct structure that allows a shroud to be used with an ESP for gas separation while also allowing some flow from below for motor cooling is proposed in US. Pat. No: 10400569. Orientation of the ducting passageways in an inclined wellbore is not considered, nor is a tapered pattern of inlet openings.

[0083] A flex joint is commercially advertised by Odessa Separator Inc. at https: / / www.odessaseparator.com / files / ugd / lac9e9 fal94cea0716461dbfae0247666e4ea0.pdf stating: “OSI has developed the FLEX TOOL which is designed to provide flexibility to bottom hole assemblies allowing them to work more freely in severely deviated wellbores. The FLEX TOOL allows the tubing string to turn in either direction and extend the production string in severely deviated wellbores. Another benefit provided by the FLEX TOOL is that it has been proven to reduce vibration from ESPs and the possibility of broken ESP shafts. The FLEX TOOL can be installed with OSI desanders or screen tools”. It is a ball-joint that allows angular misalignment of the axes and free rotation, however utilization to allow free rotation and angular misalignment of the axis of a low-side intake apparatus is not considered.

[0084] Flex joints for other downhole applications are typically pinned to prevent free rotation, for example in drilling applications. A variety of downhole flex and swivel joints are proposed in disclosures: US4425965A, US6484801B2, US6679323B2, US7131497B2, US20100018772A1, US20220065050A1, US4842059A, US7699353B2, US2147491A, US3216751A, US20060070733A1.

[0085] Referring to Fig. 1A, a wellbore 1 may receive fluids through openings between wellbore and reservoir 3 (for example perforations, screens, ports or other lower completions assembly devices as is known in the art). Fluids may flow in wellbore 4 toward a downhole low-side intake 10, which may be located below a downhole pump 9. The intake 10 may have a tubular, such as an inner housing 41. The housing 41 may be eccentrically weighted to allow free axial rotation of the tubular relative to a downstream end 10B of the downhole low-side intake 10 to align one or more inlet openings 31 in the tubular toward a low-side of the downhole low-side intake. In general, the tubular may have an eccentrically weighted part that is configured to rotate within the wellbore to open or align one or more inlet openings in the tubular toward a low-side of the wellbore. The intake 10 may have an external baffle on the tubular / inner housing 41, such as a crosswise baffle 46 as shown in subsequent figures. A swivel 60 may be between the downhole pump 9 and the intake 10, and the swivel may allow free rotation of the intake while coupling the intake to the pump and providing a conduit of flow from the intake to the pump. An external baffle includes one that is connected or oriented external to the tubular / inner housing. The downhole pump 9 may be driven via sucker or continuous rods from a surface drive head, or potentially by an electrical cable if used with an ESP (not shown). Fluids may be taken in from the wellbore to the downhole pump 9, through intake10 of the present disclosure through inlet openings 31. Gas that bypasses the pump intake and any gas that may be exhausted from any active gas separation devices (not shown) uphole of a pump intake may flow to surface within the wellbore 1, typically in an annulus 5 formed between the wellbore 1 and the production tubing 2. Liquids within the pump may have their pressure boosted sufficiently to overcome the hydrostatic head, friction pressure, and surface backpressure and flow up the production tubing 2 to a surface gathering or collection system for further processing and sale. A wellbore 1 may be substantially horizontal, or otherwise highly deviated. A low-side intake apparatus 10 may be located in a substantially horizontal portion of the wellbore (e.g. inclination between 60° and 110° from vertical). For the sake of simplicity, the intake is shown at 90° inclination, however for application with rod pumps, the pump may be landed at less than 86° inclination. Within this range of inclinations, the flow regime in the wellbore adjacent to the intake 10 may be substantially segregated (which may include stratified, chum, or slugging flow regimes). The primarily liquid phase 7 of fluid in wellbore flowing toward the pump may tend to accumulate on the low-side of the wellbore 1. The accumulation on the low-side may be enhanced by the eccentric components of the production string laying toward the low-side (the gas preferentially flows up the larger / wider part of the eccentric annulus toward the high-side). When the flow is adjacent to the intake, the flow is within an eccentric annulus, and the presence of the intake itself affects the flow regime, with a tendency to reduce the velocity of flow toward the low-side, reduce the gas holdup toward the low-side (holdup is the statistical likelihood of gas being present), and increases recirculation (recirculation is fluid slipping in a downhole direction, counter to the generally uphole direction of flow in the wellbore). The primarily gas phase 8 of fluid in the wellbore flowing toward the pump may tend to accumulate on the high-side of the wellbore. While the pump 10 may naturally rest on the low-side of the wellbore 1 where it is ideally submerged in liquid, unstable flow and coning of gas which has a higher relative mobility (lower viscosity and density) may result in free gas entering the intake of the pump even with a low-side oriented inlet. Many horizontal gas avoiders have been proposed attempting to locate or preferentially open inlet holes that are oriented toward the low-side of the pump. Examples include those discussed in detail above and additionally Pat. Publication Nos.: US5588486A, US20160319653A1, US20070051509A1, US20150204169A1, US6715556B2, US7270178B2, CN201953369U. Many proposed designs have failed or performed poorly because they are short or because they create a restriction in the flow of fluid entering the pump intake assembly. Such restriction at the intake may be especially problematic because it occurs at the lowest pressure location the entire wellbore and pump system and therefore results in gas breakout (or steam flashing in thermal operations), or other flow assurance challenges such as wax, asphaltene, or scale deposition. It's important to understand that the present disclosure may form a restriction in only a portion of the inlet opening toward the downstream end, which may be useful to control the inflow profde, and may have a large cumulative flow area through the inlet openings (typically several multiples greater than the flow area in the inner flow path through the device); which is different than a restriction formed by having a restricted inlet opening, like many prior art devices. The intakes of the present disclosure may help avoid intake of gas into the pump because a large total inlet flow area, such as with a ratio of the total inlet flow area to the flow area inside the housing, said ratio being greater than 1 or 2 or 3 or 10, may help to avoid gas breakout and flow assurance problems. The extended length of the inlet holes may draw down the fluid level in the wellbore more uniformly which helps to minimize gas coning because of the gas’ higher relative mobility into the inlet holes. Fig. 1 shows a single intake stage with low-side slots. A largeinner housing tubular may further mitigate flow assurance problems, reduces pressure drop and gas breakout, and may allow a longer intake to be effectively used with an approximately uniform inflow profile over its entire length.

[0086] Referring to Fig. IB a cross-section view of an intake device at Section IB showing an intake device 10 in a wellbore 1 with a stratified flow where primarily liquid 7 occupies the lower portion of the wellbore while primarily gas 8 occupies the upper portion of the wellbore. The device 10 may comprise an eccentrically weighted intake configured for free axial rotation to orient inlet openings 31 toward a base of the low-side intake. The one or more inlet openings 31 may be connected to feed a fluid outlet at the downstream end, such as connects the intake to the pump 9. If multiple stages are used, as discussed in other figures, each stage has a fluid outlet 48B from a fluid flow path 48. As is discussed further below, the device 10 may be structured to relatively progressively increase a restriction to intake flow, through the one or more inlet openings 31, in a direction toward the downstream end. The device 10 may be structured to relatively progressively increase the restriction to intake flow to equalize inflow along an axial length of the one or more inlet openings. The one or more inlet openings 31 may be one or more of shaped, patterned, or arranged to progressively decrease intake flow area per axial unit length toward the downstream end. The reference to restricting intake flow refers to the restricting of flux of intake flow through an entry point of the one or more inlet openings at an axial location of the intake. The reference to a progressive increase or decrease may refer to the fact that the increase or decrease happens or develops gradually or in stages in an axial direction along the tool.

[0087] Another more mathematical way of describing the intent of embodiments of the present disclosure to restrict intake flow toward a downstream end of an intake is by referring to the specific flow coefficient. Specific flow coefficient may be defined as the flow coefficient per unit of length of an intake. The equation for specific flow coefficient is Cvs = Q / dL (SG / dP)A0.5 where Cvs is the Specific flow coefficient, dL is a unit of length, SG is the specific gravity of the fluid, and dP is the pressure drop from the wellbore outside the inlet openings to the intake inner common fluid flow path. Specific flow coefficient may progressively decrease toward a downstream end of an intake and thus provides a more uniform inflow profile over the length of the inlet openings. The specific flow coefficient is a function of the inlet opening geometry and any baffles proximate to the inlet openings. Less flow area in the inlet openings results in a lower Cvs. Smaller holes with more wetted surface area (despite having the same inlet opening flow area results in a lower Cvs. Baffles will reduce the Cvs. Combinations of the parameters above will reduce the Cvs.

[0088] The intake device 10 may comprise an eccentrically weighted intake 10 comprising a tubular inner housing 41, and inlet opening(s) 31. In this embodiment the tubular housing may comprise a single row of inlet openings 31 at the low-side which have a standoff from the casing 1 provided by an external baffle 46. As above, the intake 10 may have an external baffle on the tubular / inner housing 41, such as a crosswise baffle 46 as shown. A crosswise baffle may be one that extends transverse or diagonally across the wellbore axis. A crosswise baffle may block or restrict flow in an axial direction along the well, and may direct flow, for example directing primarily- liquid flow to the one or more inlet openings or deflecting primarily-gas away from inlet openings. The liquid 7 to gas 8 interface 7” may not be uniform between left and right sides of the intake device 10, which may be common in transient operating conditions. Focusing first on the left side where there is a liquid level, the vertical velocity vectors in the liquid 7’ are shown. The velocity may increase as one moves downwards within the crescent shapedannulus formed between the intake device 10 and the wellbore 1 corresponding with the horizontal section area of the crescent shaped annulus. If the liquid-gas interface happens to stay high enough in the wellbore, then the vertical velocity of the liquid may be less than a bubble rise velocity and the intake may function to avoid gas as desired. However, as the liquid level is brought lower, the downward velocity at the interface increases and at a certain level may exceed the bubble rise velocity. When this occurs, gas may be coned at a velocity 8’ that is higher compared to velocity of the liquid 7’ due to the relative mobility of gas versus liquid - this is the condition shown with higher velocity gas on the right-hand side, and gas breakthrough in a pathway 8” when a liquid level is lowered to the position of an inlet opening 31. These gas breakthrough events are highly undesirable, and an object of this disclosure is to reduce the frequency and severity of gas breakthrough events by reducing the peak vertical velocity 7’ of the liquid 7 within this annular space by means of increasing the inflow-contributing length of the intake. Other embodiments introduce a permeable baffle to isolate the liquid separation space which is in close proximity to inlet openings 31 from the transient and turbulent flows of fluids in the wellbore. In some cases, two or more inlet openings are located in close proximity in a downstream direction of the external baffle.

[0089] Referring to Fig. 1C, a side elevation view of a long low-side intake in a curved portion of the wellbore 1 is shown. A pump 9, or alternatively another tubular of a production string such as a motor shroud, may be connected by a swivel 60 to an intake apparatus 10. The intake apparatus may comprise an inner housing 41 with inlet openings 31 with a size and spacing designed to create a specific flow coefficient that progressively decreases from an upstream end 10A toward a downstream end 10B of an intake apparatus. A bullnose 42 at the upstream end 10A may prevent flow from entering the inner housing 41 through a downhole end; the majority of flow must enter through inlet openings 31, however this doesn’t require necessarily a tightly sealing bullnose. Because of the large cumulative area of inlet openings 31 the pressure drop (dP) between the outside and inside of the inner housing 31 is very low, especially toward the upstream end 10A, and therefore leakage through small gaps or holes may be minimal. A dP across inlet openings of an operating intake may be below 10 psi at a downstream end 10B and below 1 psi at an upstream end, however, the dPs are highly variable based on the flow rate, fluid viscosity, and the length of the intake. This embodiment illustrates a prior art swivel 60 that maintains axial alignment of the intake 10 with the pump 9 above. Because of the stiffness and length of the intake apparatus, a bending moment is imparted to the pump 9, which may cause reliability issues for the pump (e.g. shaft fatigue of an ESP, rotor fatigue of a PCP, or binding and wear between a barrel and plunger of an SRP). The stiffness of the assembly may also cause a large low-side gap 51 to form between the intake 10 and the casing of the wellbore 1. The gap may be dependent upon the dogleg severity (radius) of the wellbore and the length and stiffness of the assembly. The figure shows a “build”, however similar issues may also result in wellbores that are curved from a plan-view, and such lateral curvature may additionally result in poor function of low-side orienting devices due to contact points not being as per design. An excessively large low-side gap 51 may degrade performance of a low-side intake, especially if it is so severe that the annular gap is greater on the low-side than on the high-side of the intake apparatus 10 - in this scenario the “path of least resistance” for flow (of gas and slugs in the wellbore) may move from the high-side to the low-side, and result in higher turbulence and gas holdup toward the low-side of the wellbore where inlet openings 31 are located, which may reduce the performance of the intake at avoiding gas ingestion.

[0090] Referring to Fig. ID, the benefits of a swivel 60 that allows angular misalignment between the axis of the pump 9 and the intake apparatus 10 are shown. Because the swivel allows misalignment, a bending moment is not imparted on the pump 9. Additionally, the swivel may more freely rotate in operation at a lower torque because it is not required to transmit a bending moment. Additionally, the intake apparatus may be freer to contact the wellbore in a manner as-designed which will increase the reliability of achieving the desired low-side orientation, and avoiding the presence of a large low-side gap 51. This figure also illustrates a flexible joint 80 which may be used between sections of a low-side intake apparatus to allow articulation (angular misalignment of the axis) without allowing independent rotation of the components above and below it. Alternatively, articulated swivels 60 may be used to join multiple sections of an intake assembly, or rigid couplers (such as threaded connections) may be used to join together multiple sections of an intake assembly to provide an overall intake assembly length greater than the joint length that can be conveniently transported or handled by rigs (which is typically in the range of 10m to 14m). Multiple-section intake apparatuses may have a total length from 10m to 30m, or up to 100m lengths.

[0091] Wellbore-level schematics in figures 1A and 1C through IK show only the simplest low-side intake comprising a housing with low-side inlet openings; however, these wellbore level schematics illustrating the use of swivels, flex joints, shrouds, plugs, and various liners configurations are also intended for use with low-side intakes comprising external baffles, permeable baffles, and multistage low-side + dip-tube intakes. A permeable baffle is one that is open to flow, whether by perforations, by windows, by an open structure, or other.

[0092] Referring to Fig. IE, a low-side intake apparatus 10 may be installed as a liner in a wellbore 1 above perforations 3. Flow may enter the wellbore 1 through perforations 3, primarily liquid phase fluid enters into the flow path 32 of an inner housing through inlet openings 31, then flows past the ESP motor 9” (if present), and into the pump intake 9’. In this embodiment, the liner does not have a hanger, and it shown horizontally, although it may practically be dropped of and function at inclination between approximately 70 and 100 degrees. The low-side intake portion contains inlet openings 31 that are oriented toward the low-side with a swivel 60 isolating the eccentrically weighted portion from a concentrically weighted portion above. This concentrically weighted portion may primarily comprise a receptacle 14 for a pump 9. This receptacle may be short in the case of an SRP or PCP with an intake on the lower end, however it may be long, such as the case illustrated, when used with an ESP type pump 9, which includes a low-side intake 9’ above a motor 9”, where the liner must provide a space within it to receive the motor 9”. The pump 9 or production tubing 2 may be sealed or creates a substantial restriction inside the receptacle 14 by means of a packoff 16 that substantially prevents or reduces flow into the receptacle from the upper end. Alternatively (similar to Fig. 1H, II, IK), the receptacle may be very long such that the upper end is at a height of 20m TVD (true vertical depth) or more above the pump intake such that a dip-tube is formed, and any liquids that enter from the uphole end may be primarily liquid.

[0093] Referring to Fig. IF, a low-side intake apparatus 10 may be installed in a liner, without a swivel. The liner may be oriented to place inlet openings 31 at the low-side by means of wireline orientation tools, MWD tools, scribing, mating with a receptacle in the wellbore of a known orientation, or other method as is known in the art. The liner may be held in position with a liner hanger 18 located at the upper end of the liner. Typically, liner hangers, or tubing anchors, even without seals, provide limited bypass flow-area, and therefore, a perforated portion 17 is placed in the liner between the liner hanger 18 and the packoff 16 in order to allow unrestricted flow ofprimarily-gas along the annulus during production operations. A liner deployed low-side intake may include a retrievable plug 19 that may be installed below inlet openings of the low-side intake apparatus. The purpose of a retrievable plug may be to allow mechanical intervention (such as cleanout, logging, etc.) of the wellbore below the intake apparatus without needing to remove the entire liner from the wellbore. The retrievable plug may be a nippletype slickline plug, a slip-type wireline-retrievable plug, a friction ring seated inside a pump seating nipple (PSN), or other type of plug or retention device as is known in the art. A retrievable plug may have a fish neck, as is known in the art, for latching onto. A retrievable plug may also be used at the downhole end of an intake attached to a production tubing string, such as the one illustrated in Fig. 1A.

[0094] Fig. 1G shows a liner latched at the lower end. The wellbore configuration illustrates an alternate lower completion design with an open hole liner 20 with openings to the reservoir 3 which may comprise screens, holes, slots, ICDs, or other open hole or gravel packed liner design as is known in the art. The open hole liner is hung in the wellbore with a liner hanger 22, and the low-side intake apparatus may be installed on a separate liner which is connected via a secondary liner hanger 12 inside of the open hole liner hanger 22. The secondary liner hanger may comprise a conventional liner hanger installed in a bore, or a latch-in type hanger which latches to a profde or a thread of the open hole liner hanger 22. Alternatively, the secondary liner hanger may connect to the wellbore 1 casing. The liner interior flow path may be plugged, using a solid or a retrievable plug 19. A pathway for fluid to leave the liner and enter the annulus between the wellbore 1 and the intake apparatus 10 may be provided by a perforated portion of a low-side intake liner below a plug. Typically, the perforated portion will have many large holes such that the open flow area of the holes is several multiples of the cross-section flow area of the liner itself in order to avoid creating a flow restriction.

[0095] Fig. 1H shows an intake apparatus 10 installed as a liner in the wellbore with the intake apparatus positioned above a pump intake 9’. The pump type may be an ESP with a motor 9”. If this embodiment is used with an ESP type pump, it may be desirable to locate some or all of the perforations 13 below the packoff 16 and above the motor 9” to ensure that the motor receives adequate flow by it for cooling. The liner may have no packoff. The liner may have no eccentric weights, it may be oriented by measurement tools such as MWD or wireline or other technique when it is installed. The liner may overlap with a liner hanger of the lower completion to facilitate entry of mechanical tools into the open hole liner. Alternatively, not shown, the intake assembly may be integral with the open hole liner. A receptacle 14 may comprise tubular joints having a nominally uniform inner diameter allowing packoff 16 to be spaced at any depth. An upstream end 10A of an intake apparatus 10 may be located uphole of a downstream end 10B, and flow within an intake apparatus may be in a downhole direction. In this ‘inverted’ embodiment, inlet openings 31 are still smaller and more restrictive to flow toward a downstream end, however this downstream end is now a downhole end. The one or more inlet openings 13 may thus decrease in size toward the downstream end. The uphole end 11 of the liner may be open to allow flow contribution into the top of the liner, similar to a conventional shroud dip-tube style prior art gas separator, however a benefit of this embodiment compared to the prior art may be that the flow rate at this upper end may be relatively lower, to allow for more efficient gas separation since a portion of the flow is also contributed through low-side inlet openings 31. Additionally, the restriction to flow upstream of a pump intake from frictional loss in the annular space within the shroud, as compared to a prior art shroud, may be lower. A downside of this inverted embodiment may be that thereis a production tubing string 2 that resides within the tubular of the low-side intake, which may cause problems by laying toward a low-side and blocking inlet openings 31, and may cause friction pressures of fluid flowing within the intake passageway to be higher which may require smaller inlet openings toward a downstream end 10B in order to provide a uniform inflow profde.

[0096] Fig. II shows an intake apparatus 10 installed as a liner in the wellbore with intake apparatuses 10 positioned both above and below a pump intake 9’. The pump type shown is an ESP with a motor 9”. An intake liner may not connect to the wellbore 1 casing or open hole liner. An intake liner may be bullnosed at a lower end. An intake liner may be oriented by measurement process during installation, or eccentrically weighted, or both eccentrically weighted and initially oriented during installation. No packoff, retrievable plug, or hanger may be required. Alternatively, not shown, the intake assembly 10 may be connected to a production tubular 2, and either manually oriented during installation or connected with a swivel that allows eccentric weights to orient the low-side intake apparatus.

[0097] Fig. 1J shows an intake apparatus 10 installed below an ESP type pump 9 using a motor shroud 6. The intake apparatus 10 may be connected to the pump 9 via the motor shroud 6 which creates a flow path for the liquid to pass by the motor 9” which may be required for cooling prior to entering the intake 9’. A swivel 60 may allow for the intake apparatus to self-orient inlet openings 31 toward a low-side. A parallel tubular 47 is shown, illustrating a typical well configuration with a small string used in horizontal wells for instrumentation, heating, chemical injection, or other purposes, which runs eccentrically (parallel) to the production string and pump and intake apparatus.

[0098] Fig. IK shows an intake apparatus 10 installed as a shroud connected to a production tubular 2 below a pump intake 9’. An intake apparatus 10 may be positioned above a pump intake 9’ in many respects similar to Fig. 1H. An optional swivel 60 may allow a shroud with low-side inlet openings 31 to orient, however, because shroud configurations are typically limited in the radial space available and are long (e.g. 30+ meters length), the use of a shroud with a swivel and / or eccentric weights may not be very practical, and therefore, it may be preferable to not use a swivel or eccentric weighting, and instead to orient the production tubing 2 during installation.

[0099] Fig. 2 shows an intake apparatus 10 with a crosswise external baffle 46 and a bullnose 42 that are eccentric and may function to orient an inner housing 41 with its inlet openings 31 toward the low-side. The external baffle(s) and bullnose may be rigidly coupled to the inner housing and rotate together. The intake shown may be bounded by an external baffle of the plurality of external baffles at an uphole end and a downhole end of the intake. The coupling may be by means of welding, bolting, riveting, brazing, clamping, heat shrinking or other method. The tapered inlet opening profile may be observed with larger inlet openings toward the upstream end, and smaller inlet openings toward the downstream end (which are not visible at the scale of this drawing). The small size of inlet openings toward the upstream end such as at section line 3B are illustrated later in Fig 3B. Eccentric baffles, comprising the bullnose 42 and an external baffle 46 are illustrated in an exemplary manner placed at the far downhole and uphole ends of the intake, however this is not limiting, and any permutation of placement of external baffles may be used for the function of causing correct orientation of a low-side intake. Regular placement of external baffles may be advantageous to assist with correct orientation of the intake in a wellbore with doglegs, and also to maintain standoff if the inlet openings comprise a single row directly at the low-side. If no standoff ismaintained, then inlet openings may be functionally blocked by being located excessively close to the casing at the low-side. An articulated swivel 60 may be located at the downstream end and illustrates angular misalignment of the axis of approximately 5 degrees. A coupler 43, typically a threaded connection, may connect the intake apparatus to a pump intake.

[0100] Referring to Fig. 3 A, a cross-section view of an intake device taken along the 3 A section lines of Fig. 2 is illustrated. Fig. 3A illustrates the relatively large size of inlet openings 31 toward the upstream end of the intake, the flow path 32 for fluid within the inner housing, and the profde of the bullnose 42 which has a section larger than the inner housing. By definition, bullnose 42 functions as an external baffle because its section is larger than the inner housing. Bullnose 42 may be eccentric to the inner housing, and when it contacts the casing (not shown) may cause the intake assembly to rotate to the low-side. A relatively flat (or larger radius) portion of the section view is located at the low-side which assists with achieving a correct orientation, and maintain such an orientation in operation or installation after the device has rotated to the correct orientation.

[0101] Fig. 3B illustrates the relatively smaller size of inlet openings 31 toward a downstream end of an intake. In addition to the smaller hole size that is visible in a section view, the lengthwise spacing of inlet openings is typically greater at the downstream end compared to an upstream end.

[0102] Referring to Fig. 3C thru Fig. 3F, alternative cross-sections of a low-side intake are shown. Low- side intakes with cross-sections such as are illustrated here may not require eccentric external baffles to orient inlet openings 31 toward a low-side. Embodiments such as these may be useful for installation below insert-type pumps, where the intake apparatus must conform to a maximum diameter constraint that is typically less than 60% of the casing ID. With a diameter limitation, it may be optimal to maximize the flow area in the flow path 32 inside the inner housing 41, without external baffles or other hardware. Without external baffles, it is likely that portions of the intake assembly will lay in close proximity to the casing (not shown), which necessitates the use of two or more rows of inlet openings 31 which are located to both the right and left of low-side. Eccentrically weighted tubulars such as these may also be used in combination with external eccentric baffles.

[0103] Referring to Fig. 3C, a cross-section where an inner housing is formed by a tubular 41 and a curved plate 44 that is thicker than the tubular is shown. Seam welds may couple the tubular 41 to the curved plate 44, and inlet openings 31 in the form of slots, are along the seam weld. The radius of curvature may be larger at the low-side to assist with maintaining preferred orientation of the assembly after it rotates to low-side orientation during installation.

[0104] Referring to Fig. 3D, a cross-section where an inner housing is formed by a tubular 41 and a curved plate 44 is shown where the curved plate sits inside the tubular, and a fillet type weld is used.

[0105] Referring to Fig. 3E, a cross-section where an inner housing is formed by a tubular 41 and a flat plate 44 is shown.

[0106] Referring to Fig. 3F, a cross-section where a unitary tubular is rolled into an eccentrically weighted shape is shown. The cross-section may include a relatively flat spot at the low-side to assist with maintaining preferred orientation of the assembly after it rotates to low-side orientation during installation. Inlet openings 31 may be located beyond the overlapping region. A tubular may be manufactured in this manner during the rollingprocess where a flat plate is rolled into a tubular. Alternatively, a similar section may be formed by eccentrically piercing pipe manufactured in a seamless tubular manufacturing process.

[0107] Referring to Fig. 4A, an intake apparatus is shown with a relatively small OD, which may have a small enough OD to be run attached to an insert-type pump, similar to preceding Figs. 2 and 3. The tubular may have a varying diameter along a longitudinal length of the tubular. The inner housing 41 may be tapered from a downstream end to a smaller diameter at an upstream end. While tapered tubulars may be more challenging to manufacture, this embodiment may be well optimized for hydraulic performance in operation. A smaller diameter at the upstream end may be sufficient for the flow coming in from the lower end, while a larger diameter at the downstream end may be required to keep friction pressure losses inside the inner housing 41 to a minimum to achieve a uniform inflow distribution along its length. The smaller diameter toward a downhole end may be advantageous because it occupies a smaller fraction of the wellbore cross-section, and the flow rates are highest in the annulus at a downstream end of an intake, so the smaller diameter at the downhole end assists with keeping the velocity in the annulus minimized as much as practical. Further uphole the flow rate in the annulus may be reduced because of flow that is received into the intake assembly through inlet openings distributed along its length. An eccentrically weighted tubular cross-section may not be required, as eccentric external baffles formed by a mid-body baffle 46 and a bullnose 42 may provide sufficient eccentric weighting.

[0108] Referring to Fig. 4B, a perspective view from the low-side of Fig. 4A is shown. A typical pattern of inlet openings 31 is visible. The one or more inlet openings 31 may comprise plural inlet openings that are uphole of and spaced in relatively close proximity to the crosswise baffle 46. The plurality of eccentric crosswise baffles 46 may comprise baffle plates oriented transverse to an axis 41 ’ of the tubular. Crosswise baffle 46 may include a gap 46’ toward the low-side, which may be advantageous for allowing longitudinal flow of primarily-liquid axially along the length of the intake. As slugs pass by an intake, the ability to avoid gas ingestion may be improved by allowing liquid to flow longitudinally along the low-side to improve the chances that all inlet openings 31 are covered by a liquid level during transient slug flow. The gap 46’ may provide a functional ‘flat spot’ at the low-side to improve the odds of maintaining preferred orientation of the assembly after it rotates to low-side orientation during installation. Another way of defining a flattened part is to say that an external low-side profile of the overlapping portion may be shaped to define a larger radius than an average radius of the tubular.

[0109] Referring to Fig. 4C, a perspective view of a portion of an intake apparatus similar to Fig. 4A is shown, except that the tapering of the inner housing 41 diameter occurs at a junction, rather than being gradual. The tubular may thus be formed of plural inner housings 41 of different diameters. Typically, junctions will be welded connections between an inner housing tubular 41 and a smaller diameter portion 48. Typically, a crosswise baffle 46 will be located at the junction to assist with providing a robust connection, providing alignment over the connection, closing any gaps that may otherwise be formed by the mating of two tubulars of different diameter, and providing an eccentric outer profile to orient the apparatus in the well. The eccentric outer profile may be defined by a generally circular profile which locates a center of mass of the assembly toward the low-side of the outer profile, the outer profile may include a cutout, flat spot, or higher radius portion toward the low-side. The crosswise baffle may comprise features for strengthening the joint beyond a simple butt weld, and features may include an overlap, fillet welds, plug welds, etc.; or strengthening ribs or plates that span the joint. Typically, the outer walls of the tubular 41and the smaller diameter tubular 48 may be aligned at a low-side with an offset at a high-side, and the smaller diameter tubular may contribute more to the eccentric weighting of the assembly. Alternatively, portions of the intake assembly may include an eccentrically weighted cross-section such as are illustrated in Figs 3C to 3F, while other sections may be tubulars of a consistent wall thickness.

[0110] Referring to Fig. 5A, the external baffle may comprise a lengthwise baffle 50, such as illustrated by an intake assembly with a permeable baffle. The lengthwise baffle may extend most or all of the length of the intake . The permeable portion of the lengthwise baffle of Fig. 5 A may comprise a perforated panel as shown. A lengthwise baffle may be flat as shown in Fig. 5A, or may partially or completely encircle the tubular. A lengthwise baffle may include a baffle that runs parallel to an axis of the wellbore, or near parallel. A lengthwise baffle may form a tubular within which the inner housing is located, and / or the lengthwise baffle may encircle only a portion of the inner housing.

[0111] Referring to Fig. 5B, the cross-section of Fig. 5A is shown.

[0112] Referring to Figs. 5 A and 5B, the maximum diameter, or width, of an assembly with a lengthwise baffle may be 91% of the casing ID, and may be between 80% and 95% but may even range from 50% to 100%.The lengthwise baffle may have a diameter or width close to the casing ID such that it can divide the wellbore crosssection outside the inner housing into two regions, a first region above the baffle where gas-rich, sluggy, turbulent flow typical of the wellbore flow regime is occurring, and a second region below (or inside) the baffle which is liquids rich, and isolated from the slugs and turbulence of the wellbore so that buoyancy-based separation of gas and gas bubbles can occur. The lengthwise baffle may increase the liquids holdup at the low-side of the wellbore where inlet openings 31 are located. A lengthwise baffle may have a smaller ID than the casing to improve the reliability of installation and removal from the wellbore despite casing deformations, scale, or debris in the wellbore; however, in alternative embodiments the permeable baffle may be designed to make contact with the casing, and if designed in this manner the lengthwise baffle would be flexed like a leaf spring making contact with the casing at both sides. An inner housing 41 may have an eccentrically weighted profde as shown with a weighted plate 44, or alternatively a tubular with consistent wall thickness may be used, since eccentric weighting may be provided by exemplary external eccentric baffles such as crosswise baffle 46, bullnose 42, or a high-side fin 49.

[0113] Referring to Fig. 6A, a lengthwise baffle 50 with a curved, approximately elliptical, section is illustrated in section view. The lengthwise baffle 50 may be permeable over approximately its entire surface area. Crosswise baffles 46 may couple between an inner housing 41 and a lengthwise baffle 50. The baffles may be configured such that the inner housing 41 maintains a standoff from the casing so that a single row of low-side oriented inlet openings 31 may be used without the inlet openings 31 being blocked by contacting casing 1’. Crosswise baffles 46 may include a gap 46’ toward the low-side for axial flow of liquid along the low-side.

[0114] Referring to Fig. 6B, a lengthwise baffle 50 with a curved, approximately elliptical, section similar to Fig. 6A is shown, with a closed section (forming a tubular). A closed section may have improved torsional stiffness and strength, which may make it easier to manufacture, and more robust to install and remove from a wellbore. A drawback of a closed section type lengthwise baffle is that the material toward the low-side occupies space which might otherwise be used for flow and retaining a liquid volume.

[0115] Referring to Fig. 6C, an inner housing 41 has a rectangular tubular section. A lengthwise baffle 50 may comprise a non-permeable portion 54 toward the high-side of a lengthwise baffle that is in axial proximity to an inlet opening 31. An opening 53’ that is toward a low-side of a lengthwise baffle 50 may be in axial proximity to an inlet opening 31. A rectangular section for an inner housing tubular 41 may be preferable (compared to round) because it may provide a more uniform cross-section within the annular space (a separation chamber 34 not labelled,) between it and a lengthwise baffle 50. Another potential advantage of a rectangular section is the ease of manufacturing and assembling the crosswise baffles 46 with a lengthwise baffle 50 using sheet metal techniques. A rectangular section may also be preferable for integration with flex joints; flex joints between tubulars inner housings 41 with rectangular sections are not shown, but may be arranged similarly to those discussed below, with the advantage that mating square sections are able to provide smaller clearances for the same angular misalignment, which may reduce the size of a leak path to the point that a seal boot or sleeve is not required, and link pins connections are stronger and more reliable with smaller clearances and with flat surfaces. Rectangular sections may also be more easily punched or louvered to form louvered inlet openings.

[0116] Referring to Fig. 7A, a bottom perspective view of a portion of an intake device similar to Fig. 6A with a lengthwise baffle 50 having continuously permeable portion and regularly spaced inlet openings 31. The lengthwise baffle 50 may be supported at regular intervals with crosswise baffles 46, which may optionally have a low-side gap 46’. Inlet openings may decrease in size or increase in spacing toward a downstream direction (at left of page).

[0117] Referring to Fig. 7B, a bottom perspective view similar to Fig. 7A is shown with inlet openings 31 spaced downstream from crosswise baffles 46 in relatively close proximity. This close spacing may be particularly advantageous for use at an inclination less than horizontal, such as between 60° and 89°.

[0118] Referring to Fig. 7C, a longitudinal section view with a section line that is external to the inner housing 41 of a portion of an intake device similar to Fig. 7B shows a liquid level 7” in the annulus external to an inner housing. The liquid level may pool up against crosswise baffle 46 at an angle which provides a more reliable liquid level over inlet opening 31.

[0119] Referring to Fig. 7D, a bottom perspective view similar to Fig. 7B is shown with an impermeable portion 54 of the lengthwise baffle 50 spaced relatively to cover over an inlet opening 31.

[0120] Referring to Fig. 7E, the impermeable portion 54 may function to preserve a larger height of liquid 7” and a larger volume of liquid below the lengthwise baffle as compared to a continuously permeable lengthwise baffle. This may be advantageous for improving the ability of the intake to avoid gas ingestion, especially in wellbores with severe slugging where it is desirable to retain a volume of liquid sufficient to keep the pump running full until a gas-slug has passed the intake device. Crosswise baffles may be installed at an angle (e.g. with the upper edge angled in an uphole direction as shown) which may increase the efficiency with which space in the annulus between the inner housing and the permeable baffle is used for liquid-gas separation and allow stage lengths to be reduced without substantially affecting the gas avoidance effectiveness.

[0121] Referring again to Fig. 7D, the optimal relative lengths of various portions may depend upon the intended angle of installation. At true horizontal inclinations of 90 degrees this configuration may still be effective, however a liquid level generally parallel to the intake apparatus may result in an optimal spacing between inletopenings 31 that is relatively small, in the range of 0.5 to 2 times the maximum diameter 76 (D) of the lengthwise baffle 50. A spacing between inlet openings 31 is the same as the spacing between crosswise baffles 46 and is the length of a stage 77. Typically, at installation inclinations between 70 and 89 degrees, an optimal stage length my be in the range of 1 to 3 times D. A higher stage count may improve performance and a typical number of stages may range from 10 to 50. More stages may be preferable as it reduces the liquid velocity within each stage such that effective gas separation can occur despite challenging conditions for gravity-based gas separation that includes small bubbles, foamy fluids, high rates of liquid and gas, sluggy flow conditions, and small wellbore diameters. More stages have the disadvantage of a higher cost, greater length, and if an extremely high number of stages is used, the inlet opening size for the downstream stages becomes impractically small such that plugging of the inlet openings may become a concern. The length of a permeable portion 71 may be less than half of the stage length 77. The length 74 between an inlet opening 31 and a crosswise baffle 46 may be small, in the range of 0 to 0. lx the stage length 77 (this may be used as the definition for ‘close proximity’ used elsewhere). The inlet opening length 73 may be less than 0.3x the stage length 77. The length 72 between a permeable portion of a permeable baffle 50 and an inlet opening 31 may range from Ox to 0.8x the stage length 77, and be optimized depending on the inclination of application - high inclinations close to 90° will prefer a relatively short length 72, while lower inclinations closer to 70° or less will prefer a longer length 72. This assembly may also be highly effective in applications that are deviated in the range of 45° to 70°, but are not actually “near-horizontal”, and designs for such applications may be optimized by greater lengths 72 which may be up to a length of 5x D or greater.

[0122] Compared to previous multistage limited entry buoyancy -driven gas separator designs, this apparatus may provide several advantages which include: 1) a non-cylindrical outer tubular (the lengthwise permeable baffle) which optimizes and reduces the hydraulic area both within and outside the lengthwise baffle to improve flow dynamics in the wellbore, and to improve gas separation efficiency below / within the lengthwise baffle; 2) a method of assembly which is cost effective and facilitates a high or very high stage count; 3) a gap 46’ toward the low-side to interconnect the liquid level of adjacent stages such that stages which are not filled through the permeable baffle, due to transient wellbore flow conditions, may instead be filled by adjacent stages; 4) Low- side orientation of inlet openings and / or high-side orientation of permeable portions of a lengthwise baffle increase the useable volume-per-stage for a given length, and improve the effectiveness of gravity based gas separation in wellbores with an inclination over 20 degrees; 5) facilitation of a large cross-section inner housing which allows for larger inlet openings to be used and for a longer intake while also achieving a uniform inflow profile along the length of the intake. The large cross-section inner housing may have the downside of reducing the cross-section area in the annular space between the inner housing and the lengthwise baffle, which reduces the maximum flow rate per-stage which can be used. However, with a sufficiently long intake apparatus and high stage count an overall improved performance at avoiding gas can be achieved with less risk of inlet openings plugging.

[0123] Referring to Fig. 8A, a cross-section of an intake apparatus is shown with a lengthwise baffle 50 with a generally elliptical section that partially encircles the inner housing 41. The lengthwise baffle 50 may be coupled to an inner housing 41 with crosswise baffles 46. Centralizer bands 45 may provide a generally circular profile toward a high-side, and ensure that the correct orientation is achieved and may prevent the intake from unintentionally orienting “perfectly upside down”. The centralizer bands 45 may be relatively thin in cross-sectionto minimally affect or disrupt the fluid flow in the wellbore above the lengthwise baffle. Crosswise baffles 46 and a bullnose 42 comprise a slot for accommodating a parallel tubular 47. The clearance between a centralizer band 45 and the casing may be less than the diameter of the parallel tubular 47 to ensure that the parallel tubular can not unintentionally come out of the slot. The slot in the bullnose may allow a small amount of inflow into the lengthwise baffle 50 from a downhole end, but the inner housing 41 is generally sealed at a lower end, optionally by a bullnose or by a retrievable plug.

[0124] Referring to Fig. 8B, a detail view is shown of Detail 8B of Fig. 8A. A lengthwise baffle 50 may have rolled edges 52 that mate with a profde of crosswise baffles 46 to provide robust retention of the open-section lengthwise baffle 50. Welds or other secondary fasteners may also be used at the junctions to provide additional strength and stiffness.

[0125] Referring to Fig. 8C, an alternate cross-section view is shown with a lengthwise baffle with an open polygonal section. Polygonal sections may lend themselves better to sheet metal fabrication processes for economical manufacturing. Permeable portions of the lengthwise baffle 50 may comprise only the top or the top and side profiles (as shown) of the lengthwise baffle. A centralizer band 45 may be connected to a lengthwise baffle 50 as illustrated by a weld, rivet, or other connection as is known in the art.

[0126] Referring to Fig. 9A, a cutaway perspective view of the downhole-end stage with a device having a cross-section similar to Fig. 8A is shown. A bullnose 42 may plug most of the lower end of the lengthwise baffle, and may contain a slot for parallel tubular 47 to pass. An impermeable portion 54 of a lengthwise baffle 50 may be over the axial position where an inlet opening (not shown) would be located at the low-side of an inner housing 41. The edges 52 of a lengthwise baffle 50 are rolled to increase their strength and stiffness. The permeable portion of the lengthwise baffle may comprise a pattern of round holes. The centralizer band 45 may be a spiral shape and may be connected to the lengthwise baffle by fdlet welds 45’. The spiral shape of the centralizer band may provide a low resistance to flow in the wellbore, and may also provide the necessary flexibility to pass debris or casing damage, and does not form a straight or sharp edge (like the one shown in Fig. 5A) which may be more likely to get caught and subsequently damaged during installation or removal by a ledge or debris in the wellbore.

[0127] Referring to Fig. 9B, a cutaway perspective view of the downhole-end stage with a device having a cross-section similar to Fig. 8B is shown. Features which may be manufactured with sheet metal techniques into a lengthwise baffle include punched or louvered openings 55, and stiffener features 56.

[0128] Referring to Fig. 9C, a perspective view from the low-side of Fig. 9B is shown illustrating the positions of an inlet opening 31 relative to crosswise baffle 46 and the impermeable portion 54 of the lengthwise baffle. This figure also illustrates how variations in the permeable portion of the lengthwise baffle may be varied along the length and height along the sidewalls of a lengthwise baffle. Sheet metal fabrication techniques may favor positioning of bend lines that do not intersect openings.

[0129] Referring to Fig. 9D, a perspective view of a stage of a low-side intake is shown illustrating alternate configurations of hole patterns of a lengthwise baffle, and connector features between the lengthwise baffle and crosswise baffle. In this embodiment, a crosswise baffle 46 is continuous around the low-side of an inner housing 41 to provide increased strength. Slots 50” of a lengthwise baffle 50 may mate with tabs 46” of a crosswise baffle 46 to ensure alignment during assembly and increase strength. Connections between the baffles andthe baffles to the inner housing 41 may also be welded. Additionally, holes in the lengthwise baffle such as the central hole 58 may be used for plug welding a lengthwise baffle directly to an inner housing. The tabs as illustrated in Fig. 9D lend themselves to an order of assembly where the crosswise baffles 46 are first mounted within the lengthwise baffle 50, and then the inner housing 41 may be inserted, aligned, and finally welded connections may be made to join the lengthwise baffle 50 to crosswise baffles 46 and to the inner housing 41. Typically, sheet metal fabrication is limited to lengths of 8 or 12 feet, individual stages of an intake may range from 0.6 to 4 feet in length, and overall intake apparatuses may range from 12 to 80 feet or more in overall length. Typically, multiple sections of sheet-metal fabricated lengthwise baffles are joined by welding to provide the overall assembly length required (not shown). Typically, an inner housing 41 is continuous over the position of joints between sections of sheet-metal fabricated lengthwise baffles 50, and the inner housing 41 may comprise the primary structural member. Each stage does not necessarily comprise a centralizer band 45, however multiple centralizer bands may be used along the length of an intake apparatus to provide the required strength and centralization to ensure reliable low-side orientation.

[0130] Referring to Fig. 9E, a crosswise baffle with tabs 46” is shown, similar to that in the assembly of Fig. 9D. The permeable portion may comprise a shroud that is configured to hook via tabs to the tubular. Slots 52 of a crosswise baffle may mate with a rolled edge of a lengthwise baffle. Tabs 46” are shown in greater detail. During assembly, crosswise baffles may be held at an angle and inserted into a lengthwise baffle, then aligned to place the rolled edges of the lengthwise baffle into slots 52”; tabs 46” may then be aligned with the mating slots in the lengthwise baffle as the crosswise baffles are straightened and latched into place. Crosswise baffles may be perpendicular to the axis (as shown) or angled as described earlier in Fig. 7E.

[0131] Referring to Fig. 9F, a lengthwise baffle may comprise a large opening 53 toward the high-side. A large hole when used with a non-permeable portion 54 may provide superior gas avoidance effectiveness for the same length of stage as compared to a plurality of holes or slots. A large hole 53 may also have the advantages of providing easy access for making welded connections 57 to a crosswise baffle 46 or an inner housing 41. A large hole 53 may also reduce length of a seam weld 59 that is required. For example, a seam weld 59 as pictured may be located at the high-side. A seam weld may be completed prior to assembly of the apparatus (e.g. prior to insertion of the inner housing 41). Alternatively, an intake apparatus may be assembled with an inner housing 41 and crosswise baffles 46, prior to the seam weld 59 being welded. If the seam weld 59 is made after installation of the inner housing 41, this lengthwise baffle 50 may be clamped tightly over the crosswise baffles 46 during welding in order to increase the strength and stiffness of the assembly. Additionally, the seam weld may include welding the lengthwise baffle 50 to itself and the inner housing 41. Alternatively, not shown, the seam may be made as two seam welds connecting the permeable baffle 50 to the inner housing 41 at separate locations. Crosswise baffles 50 may be sealed within lengthwise baffle 50 with a weld or other method around the perimeter. Alternatively, crosswise baffles 50 may allow a small leak path from stage to stage. Alternatively, as shown, crosswise baffles may comprise holes 46”’ to allow an intentional amount of ‘leakage’ from stage, which may improve performance in transient conditions when some stages may not be adequately filled from the wellbore through the openings in the lengthwise baffle 50. Leakage between stages may be beneficial for draining wellbore fluid from the apparatus after removal from a wellbore. Alternatively, inlet openings 31 of a tubular may be positioned towards a downhole end ofa stage and allow the fluid that between the outer and inner housings to drain into the inner housing 41. The bullnose may comprise a drain hole towards a downhole end which allows fluid within the inner housing 41 to drain during removal from the well. A drain hole may be sufficiently small such and positioned towards a low-side such that a small or negligible amount of fluid is produced through it and into the tubular during operation, or alternatively a drain hole may be plugged during operation, and the plug removed after removal from the well, typically while positioned above the hole to allow wellbore fluids to drain back into the well.

[0132] Referring to Fig. 91, another embodiment is shown similar to Fig. 9F in which a separation chamber 34 for gas separation is formed between two crosswise baffles 46, wherein the baffle between the inlet openings of the permeable baffle 53 and 53 ’ comprises a low-side inlet opening 110. The inlet opening 31 of the inner housing 41 may be oriented toward a high-side in order to maximize the stagnant volume formed within the separation chamber 35 for solids separation. Optionally, a secondary weir may be formed by a third crosswise baffle of the stage which comprises a high-side inlet opening 111 ; the purpose of this third crosswise baffle is primarily to create a stagnant area within the chamber for solids separation so that solids which setting in this area are allowed to settle and compact without being carried into inlet openings 31.

[0133] Fig. 9J shows a view inside a separation chamber for solids (the lengthwise baffle 50 is hidden) in order to better view the crosswise baffles with low-side inlet openings 110 and high-side inlet openings 111. A filter or strainer baffle may be located within a separation chamber 35 for solids; and in this embodiment the filter or strainer baffle is shown in a lengthwise orientation. Alternatively, it may be oriented crosswise. The strainer or baffle may be positioned such that flow must pass through gaps; these gaps may range in size from 0.005” to 0.25” depending on the size of the sand or debris that is intended to be blocked. Circular holes are shown but slots or mesh or other filter media may be used. A filter or strainer baffle may be used with or without a secondary weir. A filter or strainer baffle may comprise two lengthwise baffles as shown, one on either side of an inlet opening, spanning the full length of a separation chamber for solids, and located substantially towards a high-side thereby forming a channel 121 along a high-side for the filtered fluids to reach inlet opening 31. An advantage of orienting the strainer or filter baffle, as shown, in a manner that the fluid is flowing in a partially upwards direction through it, is that solids will fall off of the filter face and come to rest in the separation chamber for solids, instead of potentially plugging off the filter face with accumulation of solids; the solids may fall off the filter face during shut in events, back-flush or tubing draining operations, or even simply during the downstroke operation of a SRP. Arrows indicate the direction of flow within both separation chambers and within the high-side channel. A filter or strainer may also be useful to allow fluid within the separator to be drained through a hole in the bullnose into the wellbore during removal from the well, without losing the debris that is retained within the separation chambers for solids.

[0134] In the embodiment shown, it may not be easy to clean out debris from the separation chamber for solids. One potential technique may be to suspend the assembly with the swivel downwards and rotate and / or vibrate and / or backflush through the device to cause solids to come loose and fall out of the lengthwise baffle inlet openings 53 or 53’. Determining the amount of solids retained within the device may best be achieved by weight gain. Determining which chambers are packed with solid or loose material may be determined by feel and acoustic response (i.e. tapping them). Direct access to the separation chambers for solids for cleaning or inspection may be gained by drilling or cutting a window in lengthwise baffle 50 or by cutting off a lowside strip, and it may bepossible to plug these new holes and return a device to service after a thorough cleaning and inspection using these techniques.

[0135]

[0136] Fig. 9K shows a view inside a separation chamber for solids of an alternate embodiment wherein the tubular 41 is eccentrically located further towards a low-side of the fully -encircling outer housing (not shown), such that the tubular and outer housing are very close together or touching. Fig. 9L shows a view inside a separation chamber for solids of an alternate embodiment wherein the outer housing (not shown) has a round profile. The tubular 41 is eccentrically located toward a low-side to provide an eccentric center of mass. Another difference compared to prior embodiments is that the strainer 120 has a reduced length; its axial extent is from the crosswise baffle at the downhole end of the stage to the crosswise baffle with a high-side opening; in this embodiment one might define the separation chamber for solids by the axial length of the strainer.

[0137] Fig. 9M shows an alternate embodiment of 3 stages of an intake device, similar to Figs. 91, 9J, 9K, and 9L with additional features that include one or more of the following. The inner housing may be a rectangular tubular. The inner housing may sit flat against the lower portion 50’ of the lengthwise baffle 50. A lengthwise seam weld 50’ may be made along each side of the permeable baffle to join the two halves. Lifting connectors such as eyebolts 130 may be coupled to the tubular and include access holes 132 which are closed by installation of the lengthwise baffle lower portion 50’. Inlet openings may be louvered 31’. There may be multiple openings 53’ towards a lower side of the lengthwise baffle within the permeable portion. Lifting eyebolts may be attached to the inner housing (as shown) and protrude through large openings 53 of a lengthwise baffle, which may be made from thinner material without sufficient integrity for lifting. Inlet openings of a tubular may be formed by cutting (such as with a laser) at an angle that is aligned with the direction of flow within the inner housing and additionally tabs may be bent forming louvered inlet openings. Angled cuts may improve the alignment of flow entering the inner housing. Crosswise baffles 46 may be welded to the upper portion of the lengthwise baffle to seal the interfaces around upper portion of the gas separation chamber 34. Inserting a square or rectangular inner housing from a lower side may be advantageous because it is easier to manufacture than sliding it in from the end, and also because it allows a variety of sealing techniques to be used to seal the upper portion of the inner housing to the crosswise baffles forming gas separation chamber 34 - these sealing techniques may include simply a tight fit or small clearance, a sealant (e.g. silicone), or a gasket (like weatherstripping) to be placed at the interface. The inner housing may be retained by welding to crosswise baffles 46, or simply by installation of the lengthwise baffle lower portion 50’ which is attached by seam welds 59. A centralizer band 45 may be supported by a rib 145 as shown which may increase the strength and stiffness of the centralizer, as well as improving reliability of installation of a centralizer band in the correct position. An assembly for use in 9-5 / 8” casing, may comprise an outside diameter of approximately 7.25”, a stage length of approximately 15”, an inner housing comprising a 3x3” square tube with 3 / 16” wall thickness that is 40 feet long; lengthwise baffles 10 feet long may be assembled with crosswise baffles, strainers of 8 stages. The inner housing may have louvered inlet openings laser cut and bent to the desired opening width, and any additional components such as lifting eyebolts installed. Then, four of the 10 foot long sections may be assembled over an inner housing. Sealant may be applied to the inner housing at marked locations of crosswise baffles of the gas separation chambers before installing the 10’ baffle sub-assemblies, or sealant may be appliedonly to hard to access upper interfaces 146 of the gas separation chamber, while upper interfaces 147 of the gas separation chamber 147 may be sealed by welding with access through large inlet openings 53. Louvered inlet openings 31 ’ may decrease in size towards a downstream end (left of page). An alternative configuration of louvered inlet openings is shown in the stage at the center stage of the figure wherein the louver 131 is bent outwards; this method may be more challenging to manufacture, however, it may offer performance advantages because the flowpath within the inner housing is not partially blocked by the louvers, the inner bent and rounded surface of the louver may keep the flow attached to align flow through the inlet opening very effectively with the direction of flow within the tubular. As described previously, the main benefit of aligning the flow may be to reduce the pressure loss within the tubular to ultimately allow a smaller diameter tubular or a longer intake section to be used with an approximately uniform contribution of flow along its length. Outwards louvered openings may also be advantageous because the opening may be located relatively closer to the downhole end of a stage which better allows the assembly to drain as it is removed from a well. Another feature such a small drain hole 133 may be added towards a downhole end of stage, or simply a small gap may be left towards a low-side of crosswise baffles, or the interface left unsealed between a crosswise baffle and a lower portion 50’ of the lengthwise baffle so that each stage is able to slowly drain to the next, assuming that the gap has not filled or plugged with solids or scale in operation. Another alternative configuration of louvered inlet openings is shown in the stage at the left side of the figure, which may be most applicable to the smaller inlet openings towards a downstream end, wherein the louver 31 ’ is bent inwards and directs flow towards a comer and / or side-wall of a rectangular or square tubular; it may offer performance advantages because: it allows a lower aspect ratio hole to be used which reduces flow loss and reduces the risk of plugging, and it maintains flow attachment by directing flow along a side wall; maintaining flow attachment helps recover energy from the jet formed through inlet openings and reduce turbulence and flow losses in the tubular; preferably there is only one opening per-stage, and they may all be formed on one side to develop a consistent swirl direction within the tubular, or they may be formed on alternating side from stage to stage to minimize swirl within the tubular - selecting between these options is geometry-specific and may be evaluated with CFD simulation. Another alternative configuration of inlet openings that may be employed for the furthest downhole stage (not shown) is to position the downhole end of the tubular 41 at an axial distance from the crosswise baffle or bullnose defining the lower end of the stage; in this configuration the inlet opening of the tubular of the lowest stage may be axial.

[0138] Referring to Fig. 9G, another embodiment is shown in which inlet openings 31 are in close proximity and uphole of external baffles 46. The plurality of eccentric external baffles may comprise a plurality of tubular outer housings as shown, such as portions 54. In this embodiment one could say either that the crosswise baffle 46 is extended in an uphole direction to cover 54 the high-side above inlet openings 31 to form a dip-tube-like stage, or that a lengthwise baffle 50 extends above the crosswise baffle 46 in which the lengthwise baffle is discontinuous from one stage to the next creating a large opening 53 between discontinuous sections of a lengthwise baffle 50. The lengthwise baffle despite comprising discrete sections extends over every inlet opening 31 of an inner housing 41, thereby covering substantially the entire length of the intake. This embodiment may have a downside of having many edges to catch on things when installing or retrieving from a wellbore, and the mechanical support of each stage being independent and unsupported by adjacent stages. Each section of external baffle may be rigidlyconnected to an inner housing 41 and external eccentric baffles 46 to provide eccentric weighting, typically by fillet welds. The external baffles may be an integral piece such as a casting.

[0139] Referring to Fig. 9H, an embodiment similar to Fig. 9G is shown with a cylindrical tubular inner housing 41 inside a cylindrical tubular lengthwise baffle 50. The lengthwise baffle 50 may have non-permeable portions 54 covering the high-side over inlet openings 31 which are oriented to the low-side. The permeable portion of the lengthwise baffle may be a single large slot associated with each stage. Alternatively, the permeable portion of the lengthwise baffle may comprise a screen section, a slot pattern, or a hole pattern. Limiting the size of the openings in the lengthwise baffle (small perforations, narrow, slots, or a screen) may be useful to function additionally as a debris strainer (not shown). Slots may be sized large enough that sand can pass through (e.g. typically 1mm or greater in gap width) so as to avoid plugging up (screening out) the wellbore in the event that a well produces a substantial volume of sand. However, the potential volume of larger debris that is large enough that a single piece could significantly damage or plug a pump or inlet opening 31 is much lower, and is unlikely to entirely plug off in the wellbore annulus. An inner housing 41 and lengthwise baffle 50 may be rigidly connected and orient as-one in a wellbore. Crosswise baffles 46 may be located in a downhole direction and in close proximity to inlet openings 31. Optionally, crosswise baffles 46 may not be required, for applications at inclinations around 90 degrees.

[0140] Regarding the aspect ratio (length) of each stage, it may vary depending on the application; for example, in a very long intake deployed as a liner in a wellbore, the aspect ratio of each stage may be substantially higher (longer) than those illustrated in the disclosed figures.

[0141] In general, referring to embodiments 7B through 9H, a dip-tube stage is formed for each group of inlet opening(s) and external baffle. This is unique as compared to the prior art of dip tube separators in that it either 1) includes a low-side orientation of inlet openings, or 2) rigidly connects an inner housing with inlet openings to a permeable baffle (an outer housing) and they are oriented within a wellbore together without relative rotation between an inner and outer housing, or 3) comprises multiple stages in parallel (for example in which fluid flow paths of the low-side intake stages connect in parallel to collectively pass fluids from the low-side intake stages downstream through the inner housing), or 4) comprises an eccentrically located inner housing within a lengthwise baffle, or 5) comprises an lengthwise baffle with a non-circular section.

[0142] Referring to Fig. 10A, an articulating swivel 60 allows free rotation of an eccentrically weighted low-side intake apparatus 10 and angular misalignment of the axes 10’ of a low-side intake apparatus with the axis 43’ of a coupler 43, the coupler 43 may be connected in a co-axial manner with the component, such as a pump, above. A swivel 60 may comprise a coupler 43, which may commonly be a tapered connection such as an EUE or LP connection commonly used on the strainer bushing rod and PC pumps (i.e. big bore 3-3 / 4” and larger “big bore” size pumps typically have a 3-1 / 2” EUE female strainer bushing connection). The length of the tubular of the coupler 43 may be varied, in some embodiments it may be limited to approximately 10 inches in length or a lesser length as required to use rig tongs or a wrench to make a connection to a pump on a rig. In other embodiments, the tubular may be longer to locate the coupler 43 at a comfortable height if the assembly is held at the rig floor at floor level by a C-plate below a shoulder 65 of a swivel bushing 64. An allowable misalignment angle 69 of an articulating swivel may be present between the axis 60’ of a coupler to a pump 43 and the axis 60” of a lowerportion of the swivel 60. The angle may be between 1 and 10 degrees, and 5 degrees is illustrated as a typical amount of designed misalignment, which may be suitable for an intake assembly of 10m length designed to be run and operated in a dogleg up to 15 degrees / 30m. A swivel bushing 64 may be coupled to an inner housing 41, a weighted plate 44 (not shown), or in an alternative embodiment (also not shown) a permeable baffle 50, by means of a weld, thread, or other method (not shown). An inner housing with an overlapping portion at the low-side for eccentric weighting similar to that described in Fig. 3F is illustrated. A swivel collar 62 may be threaded to swivel bushing 64, and may have secondary retainment features such as tack welds, set screws, or other secondary retainment to prevent backoff of the thread (not shown). The swivel collar 62 may retain an upset portion 66 of a coupler 43. Because of the clearances in a swivel of this design (without a ball), relative movement between the coupler 43 and the intake apparatus may result in relative movement and impact forces within the swivel which have the advantage of breaking static friction and ensuring that in operation the intake assembly is able to rotate to an optimal orientation, and the disadvantage of creating vibrations, potentially with residual torque or dynamic torque which may necessitate high torques be used when making up nearby connections and / or secondary restraint for threaded connections. It is not necessary to have a swivel bushing 64, and an alternative embodiment (not shown) may for example have a swivel collar 62 coupled directly to an inner housing 41, and when handling the assembly at a rig the assembly may be held in slips (with slips set on the coupler 43 or inner housing 41 or lengthwise baffle 50), or by any other suspension technique. Alternatively, a swivel may be designed “inside out” when a larger diameter coupler 43 is required, such that the component functioning as the swivel collar 62 resides primarily within the coupler 43. Alternatively, the swivel may be designed “upside down” in which the swivel collar 62 is rigidly connected to a coupler 43, and the shoulder 66 that resides within the swivel is part of the intake apparatus 10. Another drawback of this design without a ball is that a reasonably large clearance may be required to achieve the misalignment geometric requirements, and the leak path through the swivel may degrade the performance as the swivel sits at the top of the intake assembly and may be positioned at a location relatively high in the casing where it may be prone to ingest gas through this leak path. In some cases, the swivel may be configured to allow a parallel misalignment of an axis of the tubular with an axis of the swivel.

[0143] The tubular component 41 (which may optionally have eccentric crosswise baffles, or comprise an inner housing with an eccentric lengthwise baffle) may have a distance of misalignment 61 between an axis 60” of a lower portion of a swivel 60 and the axis 41’ of the tubular component 41. This distance of misalignment may serve functionally the same benefit as an eccentric external baffle which is to move the center of mass of the tubular component 41 below the center of rotation; this is only really effective when the maximum diameter of a component above and below the swivel are different, and can be effectively implemented for both configurations where the component having a larger diameter is above the swivel and where the component having a larger diameter is below the swivel. The center of rotation at the upper end of the tubular component may be the axis of the swivel 60”, and similarly, the center of rotation at an upstream end of a tubular component may be defined by an outer profile of an eccentric external baffle where it contacts the casing. Note, that while the swivel’s purpose is primarily to provide for axial misalignment, the clearances of a loose-fitting swivel such as that illustrated in Fig. 10A will result in an additional small (typically less than 0.05”) distance of misalignment also. Other embodiments, not shown, mayintegrate a designed eccentricity (distance of misalignment) at a location within the lower portion of the swivel 60 that is closer to overlapping portion of the swivel, which does not depart from the disclosure.

[0144] Referring now to Fig. 10B, a ball-joint alternative is shown. Functionality and alternatives are similar to the discussion above for Fig. 10A, with the difference being that a substantially spherical surface 68 may comprise the shoulder 66 of a swivel pin 43. Mating surfaces or inserts to the spherical surface may be used on the inside of the swivel bushing 66, and are typically formed by inserts as shown. Inserts may comprise a seal, or a seal ring may be used - located at the axial location intersecting the pivot point; or inserts may be metallic, preferably with a hard and corrosion resistant surface, and may be assembled loosely to allow free rotation. A ball joint may have the relative advantage of having tighter tolerances, or a seal with interference to reduce or eliminate relative axial movements of the coupler 43 and the intake assembly 10, and may have tighter clearances or a seal that reduce or eliminate any potential gas ingestion at the swivel. Weld prep details 64’ on swivel are shown which include a groove for a butt weld towards a low-side of a square tubular, and an overlapping joint towards a high-side that comprises both a round hole for a plug weld, and an angled surface for a scalloped fdlet weld. Plug and scalloped weld geometries can help ensure the weld has greater than 100% of the strength of the components being joined. In other embodiments wherein the central axis is approximately aligned with the axis of the pump or production tubular, a distance of misalignment 61 may be zero.

[0145] Referring to Fig. 11A, flex joints are shown, which may be used between sections of a low-side intake to allow independent articulation. A flex joint may have the advantage compared to a swivel of not allowing independent orientation of the section below and above, which may be useful, for example, in a scenario where one section of a low-side intake is strongly eccentrically weighted and another section is weakly eccentrically weighted or not eccentrically weighted. A flex joint may have the potential advantage of being lower cost to manufacture than a swivel. The flex joint may be configured to not seal, and in which a crosswise baffle is located within close proximity in downhole direction from the flex joint, and a non-permeable portion of a lengthwise baffle covers a high-side above the flex joint. A flex joint may comprise an inner housing 41 of a downhole section and an uphole section of an intake. A tubular link 82 may bridge the gap between them, and link pins 84 connect the tubular link 82 to both inner housings 41. A retainer 84 for the link pins may be used to keep them in place, and a snap ring is shown in this figure. However, snap rings may not be robust enough for the application and other retainers on the end of the link pins may be employed such as forging the end (which may also couple them tightly within the holes of an inner housing 41), or resistance welding a cap of a larger diameter than the link pins 84 to the end of the link pin. Relatively large clearances are required to allow angular misalignment of the axes, which may present an unacceptably large leak path. The acceptable amount of leakage path size at a flex joint may be larger than for a swivel because the swivel is located at the furthest downstream end of an intake apparatus where the dP is greatest, while a flex joint is located at a partially upstream location where dP is less and therefore a lower amount of leakage will occur for a leak path of a similar geometry. In order to reduce or seal the leak path of a flex joint, a “boot” or “sleeve” (not shown) may be used to cover the joint, either on the inside or the outside; such a boot may be constructed of rubber (e.g. like a CV joint on a vehicle), or for thermal applications a metal sleeve may simply be a section of braided stainless steel such as is used to armor or jacket flexible hoses where the small pores of the braided jacket sufficiently reduces the leakage to an acceptable small amount; or the sleeve may be a metal bellowssuch as is used in high temperature flexible hoses. Note, that while the flex joint’s purpose is primarily to provide for axial misalignment, a flex joint may also naturally allow for some distance of misalignment.

[0146] Referring to Fig. 1 IB, a longitudinal cross-section is shown illustrating the alignment of components of Fig. 11A. As shown, the swivel (flex joint) may comprise a plurality of tubular housings (41) that are one or more of nested or linked together to pivot.

[0147] Referring to Fig. 11C, a perspective view of a tubular link is shown, and illustrates axially- elongated holes 85 for link pins, comprising a slotted shape. Elongated holes may allow for angular misalignment of the axes in a second dimension also - typically, a flex joint may be aligned to allow the primary movement of the assembly in an “up and down” manner associated with typical horizontal wellbore geometries comprising an increasing inclination that builds toward horizontal; however, many wells also have turns (lateral changes in the wellbore azimuth) that may be present at the depth where an intake apparatus is installed, and lateral flexibility of a flex joint may be useful to allow the intake apparatus to correctly orient and lay at a location as low as reasonably practical in the wellbore.

[0148] Referring to Fig. 1 ID, an alternative flex joint is shown with links 88, instead of a tubular link. This configuration may be advantageous for reliability, simplicity to manufacture, and provide a less restricted flow area through the ID. The downsides of this design are that torsional loads may result in twisted loads on links 88 and link pins 84 which may damage link pin retention features 86, and a large leak path, which would certainly need to be covered with a sleeve or boot. Alternate embodiments of a flex joint are also possible, such as using a chain or wire rope, or simply using a segment of material between inner housings 41 that has greater flexibility than the inner housings 41. A flexible segment may comprise something like a flexible hose that is coupled to inner housings 41 above and below. Other flex joint configurations are possible without departing from the disclosure.

[0149] Referring to Figs. HE and 1 IF, an alternative embodiment of a flex joint 80 is shown with tubular components 41 on both sides of the flex joint having rectangular sections. A tubular component 41 toward an upstream end 10A may have a smaller section and fit telescopingly within a tubular component toward a downstream end 10B. An axis 41’ is defined along the centroid of each tubular component 41. A link pin 84 may be offset may not be aligned with an axis of a tubular component, as shown. A distance of misalignment 61 between the axes 41 ’ of tubular components 41 may provide a benefit of lowering a center of mass, and may also be used with other flex joint permutations not explicitly shown, such as those with round tubular components or without a baffle. An angle of misalignment 69 between the axes 41’ is 6° in this example. A lengthwise baffle 50 may be used as an alternative to a ‘boot’ or ‘sleeve’ to cover the opening formed by the loose clearances of a flex joint, in which a non-permeable portion 54 covers over the high-side adjacent to and for a certain length extending in an uphole direction relative to the flex joint - the clearances within the flex joint essentially forming an additional inlet opening for flow.

[0150] Referring to Fig. 11G, a simple low-side intake, similar to Fig. 2, is shown, which does not have a lengthwise baffle extending the length of the intake apparatus 10. A flex joint 80 may be formed between telescoping tubular components 41. A single long link pin 84 may extend through both sides of telescoping tubular components 41 forming a pivot, and may be retained by an external baffle with an axially extended portion 46””; during assembly. First the tubular components are aligned, then link pin 84 is inserted, and finally external baffle46”” is installed and coupled to a tubular component 41, typically with a welded connection. External eccentric baffle 46”” may function to retain the link pin 84, to form a rotational contact surface that has a center above the center of mass of the intake apparatus, and to block gas entry directly into the leak path formed by the clearances between tubular components 41 of a flex joint 80. Advantages of using tubular components with a polygonal crosssection, such as is illustrated in Fig. 11G, are the improved uniformity of the cross-section formed in the annular space between the tubular component and the wellbore casing, the ease of manufacturing (forming holes, aligning external baffles, ease of forming sheet metal features such as louvered inlet openings 31’), and improved reliability of flex joints which are better supported by large flat bearing faces. Louvered inlet openings 31 ’ may serve to align the angle of flow entering the flow path 32 of a tubular component through the inlet opening 31 ’ to an angle that more closely matches the direction of flow within the tubular component 41; this may be advantageous to reduce the frictional pressure losses within the flow path 32, which ultimately enables a tubular component of a smaller diameter or a longer length to be used while achieving approximately uniform inflow per unit length along the intake. The relatively high velocity flow through the inlet openings toward a downstream end of an intake device, may also function as a jet pump to help draw fluid from inlet openings further toward an upstream end.

[0151] Referring to Fig. 11H, a louvered inlet opening 31’ may be formed in a tubular component 41. The inlet opening may accelerate fluid in a direction substantially aligned with the direction of flow within the tubular component. As described above, aligning the inlet openings with the direction of flow within the tubular component may help reduce turbulence within the tubular component, and may thereby reduce the pressure drop along a tubular component of a given diameter and length, and additionally the aligned and high velocity flow entering through inlet openings toward a downstream end may even help entrain and motivate flow from the upstream end of the tubular component (analogous to the jets of a lazy river at a water park). A louvered inlet opening may be formed by punching method. For manufacturing an inlet opening a tubular component, a punch may be used to shear the tubular component at the gap forming the inlet opening, which may create a deformed region on one or both sides of inlet opening 31 ’. A deformed region toward an upstream end of a louvered inlet opening may have a length 36 which is generally deformed inwards by an external punch. A deformed region toward a downstream end of a louvered inlet opening may have a length 37 which is generally deformed outwards by an internal punch. In alternative embodiments a deformed region may be present on only one of either side of a louvered inlet opening. The mechanism of an internal punch is not shown, however it may comprise a hydraulic piston substantially aligned with the tubular component 41 and a set of ramps and wedges comprising the punch. It may be advantageous to use an internal punch because it is able to anchor within the tubular to initiate a sharp shear plane where the louvered inlet opening 31 ’ is formed, which can be challenging in thick material. It may also be advantageous because the internal punch can be configured to provide a rounded / curved surface 38 toward a downstream end of an inlet opening; and this rounded serves to keep the flow entering through the inlet opening 31’ attached to the lower internal surface of the tubular component. Keeping the flow attached to a curved surface at the downstream edge of an inlet opening may be advantageous because it will better align the inlet flow with the direction of flow within the tubular. A sharp comer may be formed at an upstream edge of an inlet opening, and this is advantageous to allow the flow to easily detach from the surface. An external punch which is aligned with the internal punch (or die) is pressed into the tubular to shear (cut) the inlet opening and deform the adjacent region at an upstream end accordingto the designed shape. A single set of punches may be used to create a pattern of inlet openings having a differing opening area along the length of a tubular component by simply varying the depth of the punch. The internal punch (or die) may have a sufficient length and a sufficiently tight fit to adequately support the tubular component to prevent deformation in undesired locations. In alternative embodiments, not shown, similar louvered inlet openings 31 ’ may be formed in sheet metal tubular components having a polygonal section in which the inlet openings are formed before the tubular component is closed.

[0152] Referring to Fig. 12A, a multistage intake apparatus 10 may comprise a concentric permeable baffle 50 and inner housing 41. The apparatus 10 may comprise a plurality of intake stages that each are formed of a tubular within the outer housing and are separated from adjacent intake stages by crosswise baffles. The intake stages may have one or more inlet openings distributed circumferentially around the tubular. The intake stages may each have an eccentrically weighted baffle that defines a baffle inlet opening and is configured to rotate relative to the tubular to orient the baffle inlet opening toward a low-side of the wellbore. The eccentrically weighted baffle is within the separation chamber of each stage. The downhole low-side intake 10 may be formed of two or more intake stages connected end-to-end. An outer housing or lengthwise baffle may be one that has a permeable portion, comprising at least one opening 98, which is located toward an uphole end of each separation chamber 34 (or stage). The permeable portion may extend a longitudinal length of an inlet stage that defines the one or more inlet openings. Each stage may be sealed from adjacent stages by crosswise baffles 46, or crosswise baffles 46 may allow leakage between stages as described previously. Crosswise baffles, define a boundary between adjacent stages. The permeable portion may be supported concentrically or eccentrically over the tubular by crosswise baffles. For one or more of the plurality of intake stages, the eccentrically weighted baffle may be configmed to substantially cover the one or more inlet openings of the tubular and permit flow into a low-side-oriented inlet opening, or portion thereof, of the one or more inlet openings of the tubular. Each stage may comprise an inner eccentric weighted baffle 90 which covers a portion of the inlet openings 94 of an inner housing 41 that are oriented toward a high-side. In this embodiment, a swivel is not required, and inlet openings 94 are circumferentially distributed around an inner housing 41. The flow within a separation chamber 34 of each stage may be forced to pass an opening 92 of the inner eccentric weighted baffle 90 which is oriented to the low-side by gravity. An inner eccentric weighted baffle 90 may be partially uphole and span at least the length of the inlet openings 94 as shown and discussed further in Fig. 12B; or an inner eccentric weighted baffle 90 may be entirely uphole of inlet openings 94 and substantially block flow around at least half the circumference while allowing flow only toward a low-side as discussed further in Fig. 12C; in this embodiment a concentric region between the tubular and outer housing is required. Each separation chamber 34 is defined on an uphole and downhole end by a cross-wise baffle 46, with exceptions that: 1. a downhole end of a furthest downhole stage may comprise a bullnose or other structure which also blocks flow into the downhole end of the tubular 41; and 2. that a upper end of a furthest uphole stage does not actually require a cross-wise baffle 46 for function instead it may be open for flow from above and another support structure or guide such as a bevel or muleshoe may be used at the upper end of the uphole stage (not shown).

[0153] Similar to a prior art disclosure, this figure is shown with variable stage length, with a shorter stage length toward a downstream (uphole) end. Any combination of stage-lengths is viable with a corresponding inlet opening pattern. Shorter stages may provide effective gas separation for a relatively lower flow rate per-stage; andcorrespondingly, a more restrictive inlet opening (than would otherwise be required) should be used for shorter stages such as those shown toward the downstream end of Fig. 12A. An alternative configuration such as an embodiment with relatively longer stages toward a downstream end may allow for more uniform inlet opening 31 sizing between stages while maintaining good gas avoidance performance. It may be preferred to optimize gas avoidance performance by targeting an approximately equal flow rate per-unit of length of an intake, which may be achieved by uniform stage lengths with an appropriately tapered pattern of inlet openings. An exception to this is that liquid availability may be highest for the stages located both toward the far upstream end and the far downstream end in wellbores with severe slug flow regimes; this is because slugs of liquid from below first lose their liquid into the stages at the upstream end of the intake creating a less liquids-rich flow toward the downstream end of the intake; then after the liquid slug has passed in the main direction of flow, a refluxing or ‘fallback’ liquid slug may flow in a downhole direction; these refluxing slugs of liquid from above first lose their liquid into the stages at the upstream end of the intake creating a less liquids-rich flow toward the downstream end of the intake; therefore, in order to optimize an intake apparatus for these wellbore flow dynamics, it may be desirable to use either shorter stage lengths toward both an upstream and downstream end, or to use inlet openings at both the far upstream and downstream ends of the intake apparatus that are larger than the size that would otherwise achieve a uniform influx profile over the length of the intake apparatus.

[0154] Referring to Fig. 12B, inner eccentric weighted baffle 90 is shown over an inner housing 41, with an opening 92 that may allow primarily inwards radial flow through it into inlet openings 94. In the example shown, the inner eccentric weighted baffle low-side-oriented opening substantially covers inlet openings of the tubular and permits radial flow into the one or more inlet openings of the tubular. The inner eccentric weighted baffle 90 rotates freely over the inner housing 41, and may be supported by axial retention features (not shown), and / or bearings. Alternatively, not shown, an inner housing 41 or a portion of it may comprise low-side inlet openings and an eccentric weight such that the entire inner housing 41 rotates within a concentric permeable baffle 50 to orient inlet openings toward a low-side within the permeable baffle 50. Alternatively, not shown, an inner housing 41 may be eccentric within a permeable baffle, and comprise inlet openings only on a low-side; in this alternative embodiment an inner housing 41 rotates eccentrically within and relative to a permeable baffle 50; the inner housings 41 of adjacent stages may be connected to orient together or independently. These alternative embodiments may be more expensive to manufacture, or more likely to fail to achieve orientation due to debris or bending of the assembly, but may be viable functional alternatives.

[0155] Referring to Fig. 12C, a single stage of a multi-stage intake, with an inner eccentric weighted baffle 90 is shown over an inner housing 41, with an opening 92 that allows primarily axial flow in a downhole direction to inlet openings 94. In the example shown, the inner eccentric weighted baffle low-side-oriented opening 92 permits axial flow in a downhole direction within an annular separation chamber 34 between the tubular 41 and the outer housing 50. Inlet openings 94 may be distributed around the perimeter of an inner housing 41. Eccentric weights 96 may be coupled to the inner eccentric weighted baffle 90 to provide eccentric weighting, simple weight rods are illustrated that may be coupled to the baffle (coupling means not illustrated). Retaining rings or bearings 99 may be used to support an inner eccentric weighted baffle 90 to maintain the desired axial position while allowing free rotation; these rings are shown coupled to the tubular, but may alternatively be coupled to the housing, or maybe in both locations; these rings also function to restrict / seal flow from passing in the clearance between an inner eccentric weighted baffle 90 and a tubular 41 or housing 50. Because of the need to achieve a seal or restriction at any rotational position of the inner eccentric weighted baffle, this embodiment requires a concentric separation chamber, or at least a portion of the separation chamber that is concentric. This embodiment may also be used with an intake assembly with a rotary shaft extending therethrough, as per patent family PCT fding CA 3,158,008 in order to improve gas avoidance performance at high wellbore inclinations (such as over 80 degrees); specifically as an improvement to embodiments represented by Figures 8B, 8C, 8D of CA 3,158,008 - these embodiments comprising a multistage low-side intake with a thru shaft and an impeller may be improved by addition of an inner eccentric weighted baffle 90 with a low-side axial flow path for flow in a substantially downhole direction within the separation chamber formed between the outer housing and inner housing. An exemplary embodiment is illustrated in Fig. 13. Note that embodiments of Figs. 12A through 12C may be used in combination well wellbore configurations of Figs. 1A through IK despite each stage having independently orienting low-side openings.

[0156] Referring to Fig. 13A, a single stage of a multi-stage intake is illustrated, with an inner eccentric weighted baffle 90 over an inner housing 41, with an opening 92 that allows primarily axial flow in a downhole direction to an impeller 103. The impeller is housed between an upper diffuser 101 and a lower diffuser 102. For one or more of the plurality of intake stages, the intake stage may comprise one or more impellers 103 that are structured to convey fluid from a fluid flow path or separation chamber of the intake stage 34 into an inner common fluid flow path 32 of the intake stage, the inner common fluid flow path being defined by the tubular 41. An inner common flow path 32 may be defined by the tubular 41 and diffusers 101 and 102 and an inner passageway of impeller 103. In some cases, one or more impellers may be between adjacent intake stages, and are structured to convey fluid from a fluid flow path of each intake stage into an inner common fluid flow path of the intake stage, the inner common fluid flow path defined by the tubular. The upper diffuser may comprise a bushing 104 which provides radial support to a sleeve 105. A shaft sleeve 106 may provide axial support for impeller 103. A lengthwise baffle 50 may comprises inlet openings 98. Arrows illustrate the path of flow within a stage. The flow paths through the upper diffuser 101 are illustrated more clearly in the perspective view of Fig. 13B. In this embodiment the outer passageway (fluted) through the upper diffuser and the outer passageway of the impeller may perform the equivalent function of inlet openings 94. A bearing or bushing 99 may support the inner eccentric weighted baffle 90 and may also provide a seal or restriction to flow between the ID of the inner eccentric weighted baffle 90 and the tubular (or upper diffuser as shown). The OD of the inner eccentric weighted baffle 90 may provide a restriction to flow or a seal to the ID of the lengthwise baffle 50 via a tight tolerance, or via other techniques not shown such as a sealed bearing or a seal. Eccentric weights 96 may be coupled to the inner eccentric weighted baffle to eccentrically position its center of mass so it rotates under gravity to position passageway 92 of an inner eccentric weight baffle towards the low-side. An annular strainer / filter 120 may be located within separation chamber 34 to trap any large solid debris within that chamber and prevent them from plugging passageways of the impeller or otherwise damaging the pump. The strainer / filter may be a plate-shaped, or it may have a pleated or conical profile in order to increase the surface area and open-area. Retaining large debris within the separation chamber allows debris to be removed from the wellbore when the pump is removed. Referring to Fig. 13B, a portion of a single stage of themulti-stage intake of Fig. 13A is illustrated, with an inner eccentric weighted baffle 90. The perspective view better illustrates a potential configuration of eccentric weights, supports, flow paths, and vanes.

[0157] Referring to Fig. 13C, an inner eccentric weighted baffle 90 is illustrated with a strainer or filter 97. The strainer 97 may reside towards an upstream end of inlet opening(s) 92 which are oriented towards a low- side in use. The strainer may contribute to the eccentric weighting of the center of mass of the inner eccentric weighted baffle in addition to a weight 96, or alternatively, the strainer alone may comprise the weight. The strainer may define a permeable lengthwise portion in order to increase the surface area to provide a sufficient open area that it does not readily plug with a small amount of debris or sand, and to reduce the pressure drop through the strainer to a negligible amount. The strainer may have a permeable crosswise portion at an upstream end. A channel 121 for filtered fluid may be formed within the lengthwise strainer. The inner eccentric weighted baffle and strainer may be used with or without the rotating through shaft (i.e. it could be used in any embodiments such as Fig. 12A, 12B, 12C, 13A, 13B).

[0158] Table of Parts:

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A downhole low-side intake comprising: a tubular, which has an eccentric center of mass that is configured to rotate within the wellbore to align inlet openings in the tubular toward a low-side of the wellbore; and an external crosswise baffle on the tubular.2 The downhole low-side intake of claim 1 in which the inlet openings decrease in size toward a downstream end.3 The downhole low-side intake of claim 2, in which the inlet openings comprise inlet openings that are uphole of and spaced in relatively close proximity to the external crosswise baffle.4 The downhole low-side intake of any one of claims 2 - 3 further comprising an inlet section that defines the inlet openings, with the inlet section having an inlet section length to outside tubular diameter ratio of greater than 10:1.5 The downhole low-side intake of any one of claims 1 - 4 in which the inlet openings are structured to relatively progressively increase a restriction to intake flow, through the inlet openings, toward a downstream end.6 The downhole low-side intake of claim 5 further comprising an inlet section that defines the inlet openings, in which the inlet openings are structured to equalize inflow along a longitudinal length of the inlet section.7 The downhole low-side intake of any one of claims 5 - 6 in which the inlet openings are one or more of shaped, patterned, or arranged to progressively decrease intake flow area per longitudinal unit length toward the downstream end.8 The downhole low-side intake of any one of claims 1 - 7 in which the tubular is eccentrically weighted by having one longitudinal edge rolled inside another longitudinal edge to form an overlapping portion that is sealed together.9 The downhole low-side intake of claim 8 in which an external low-side profile of the overlapping portion is shaped to define a larger radius than an average radius of the tubular.10 The downhole low-side intake of any one of claims 8 - 9 in which the inlet openings comprise two or more rows of inlet openings along a longitudinal length of the downhole low-side intake, with each row at or adjacent a respective longitudinal edge of the overlapping portion.11 The downhole low-side intake of any one of claims 1 - 10 further comprising a swivel that is downstream of the tubular and about which the tubular is eccentrically weighted to rotate within the wellbore.12 The downhole low-side intake of claim 11 in which the swivel is configured to articulate.13 The downhole low-side intake of claim 12 in which the swivel is configured to allow relative movement to cause an angular or parallel misalignment of axes of the tubular and an uphole portion of the swivel.14 The downhole low-side intake of any one of claims 11 - 13 in which the swivel comprises a ball joint.15 The downhole low-side intake of any one of claims 1 - 14 further comprising a flexible connection that is downstream of at least a section of the tubular and is connected to rotate together with the tubular within the wellbore.16 The downhole low-side intake of claim 15 in which the flexible connection comprises a plurality of tubular housings that are one or more of nested or linked together to pivot.

17. The downhole low-side intake of claim 16 in which the flexible connection is one or more of: at or adjacent a downstream end of the downhole low-side intake; and between plural intake stages of the downhole low-side intake.

18. The downhole low-side intake of any one of claims 16 - 17 in which the flexible connection comprises a flex joint that is configured to allow relative movement to cause an angular or parallel misalignment of axes of adjacent intake stages, of the downhole low-side intake, upstream and downstream of the flexible connection without allowing relative rotation of upstream and downstream ends of the flex joint.

19. The downhole low-side intake of claim 18 in which: the flex joint is non-sealing; the external crosswise baffle is located within close proximity in a downhole direction from the flex joint; and a non-permeable portion of an external lengthwise baffle covers a high-side of the flex joint.

20. The downhole low-side intake of any one of claims 1 - 19 in which the external crosswise baffle comprises a bullnose at an upstream end of the downhole low-side intake.

21. The downhole low-side intake of claim 20 in which the bullnose comprises a drain hole.

22. The downhole low-side intake of claim of claim 21 in which the drain hole comprises a removeable plug.

23. The downhole low-side intake of any one of claims 1 - 22 in which the inlet openings are louvered to direct flow that passes through the inlet openings to align with an axis of the tubular.

24. The downhole low-side intake of claim 23, in which the inlet openings are louvered via a punching process.

25. The downhole low-side intake of claim 24, in which the inlet openings are louvered outwards and have a rounded surface on an inner downstream edge.

26. The downhole low-side intake of claim 23 in which the inlet openings are louvered inwards to direct flow that passes through the inlet openings to partially align with an axis of the tubular and to direct flow that passes through the inlet openings toward an inner comer or side wall of a rectangular or square tubular.

27. The downhole low-side intake of any one of claims 1 - 26 in which the tubular comprises an inner housing that is rigidly coupled to the external crosswise baffle.

28. The downhole low-side intake of claim 27 further comprising an external lengthwise baffle.

29. The downhole low-side intake of claim 28 in which the external lengthwise baffle at least partially encircles the tubular.

30. The downhole low-side intake of any one of claim 28 - 29, in which the external lengthwise baffle comprises an eccentric external lengthwise baffle.

31. The downhole low-side intake of any one of claims 28 - 30 in which the external lengthwise baffle comprises a permeable portion.

32. The downhole low-side intake of claim 31 in which the permeable portion extends lengthwise a longitudinal length of an inlet section that defines the inlet openings.

33. The downhole low-side intake of claim 32, in which the permeable portion is supported eccentrically over the tubular by eccentric external baffles.

34. The downhole low-side intake of any one of claims 31 - 33 in which the external lengthwise baffle comprises a non-permeable portion adjacent to the inlet openings of the tubular.

35. The downhole low-side intake of any one of claims 31 - 34 in which the permeable portion, in operation, is structured to isolate turbulent and gassy wellbore flow from low-side liquid gathering space, in use, below the permeable portion.

36. The downhole low-side intake of any one of claims 31 - 35 in which the permeable portion comprises a perforated panel.

37. The downhole low-side intake of claim 36 in which the permeable portion comprises a shroud that at least partially encircles the tubular and is configured to hook via tabs to the external crosswise baffle.

38. The downhole low-side intake of any one of claims 28 - 37, in which one or more of the inlet openings are located in close proximity in a downstream direction of the external lengthwise baffle.

39. The downhole low-side intake of any one of claims 28 - 38 in which: the external crosswise baffle comprises a plurality of external crosswise baffles; and the tubular forms an inner housing and the external lengthwise baffle forms an outer housing, which is rigidly connected to the inner housing.

40. The downhole low-side intake of claim 39 in which: the downhole low-side intake is formed of two or more intake stages connected end-to-end; and each intake stage is bounded by external crosswise baffles at an uphole end and a downhole end of the intake stage.

41. The downhole low-side intake of claim 40 in which, for each intake stage: the inlet openings comprise low-side oriented inlet openings that are located toward a downhole end of the intake stage; and the outer housing has at least one opening to make it permeable, with the at least one opening being located toward an uphole end of the intake stage.

42. The downhole low-side intake of claim 41 in which fluid flow paths of the intake stages connect in parallel to collectively pass fluids from the intake stages downstream through the tubular.

43. The downhole low-side intake of any one of claims 39 - 42 in which the external lengthwise baffle comprises a plurality of tubular outer housings.

44. The downhole low-side intake of claim 43 in which the external crosswise baffle is configured to one or more of: maintain a standoff from a well casing; define an eccentric center of mass to eccentrically weight the tubular; or direct flow patterns around the downhole low-side intake and the inlet openings.

45. The downhole low-side intake of any one of claims 43 - 44 in which the external crosswise baffle comprises a plurality of eccentric external crosswise baffles spaced in a longitudinal direction along the downhole low-side intake.

46. The downhole low-side intake of claim 45 in which the plurality of eccentric external crosswise baffles comprise external crosswise baffles at an upstream end and a downstream end of an inlet section of the downhole low-side intake.

47. The downhole low-side intake of any one of claims 45 - 46 in which the plurality of eccentric external crosswise baffles comprise baffle plates oriented transverse to an axis of the tubular.

48. The downhole low-side intake of any one of claims 42 - 47 in which the tubular comprises low-side inlet openings.

49. The downhole low-side intake of any one of claims 42 - 48 further comprising a crosswise baffle that comprises low-side inlet openings.

50. The downhole low-side intake of claim 49 in which the external lengthwise baffle fully encircles the tubular, and a gas separation chamber is defined between a permeable portion of the external lengthwise baffle and the crosswise baffle with low-side inlet openings.

51. The downhole low-side intake of claim 50 in which a solids separation chamber is defined between the crosswise baffle with low-side inlet openings and the external crosswise baffle, which is at the downhole end of an intake stage of the downhole low-side intake.

52. The downhole low-side intake of claim 51 in which a strainer or filter is within the solids separation chamber.

53. The downhole low-side intake of any one of claims 51 - 52 in which a crosswise baffle with a high-side opening is within the solids separation chamber.

54. The downhole low-side intake of any one of claims 1 - 53 in which the tubular has a varying diameter along a longitudinal length of the tubular.

55. The downhole low-side intake of claim 54 in which the tubular is formed of plural inner housings of different diameters.

56. The downhole low-side intake of claim 55 in which the external crosswise baffle comprises an eccentric external crosswise baffle located at a junction between inner housings of the tubular, the inner housings having different diameters.

57. The downhole low-side intake of any one of claims 1 - 56 with a pump intake coupled in an uphole direction of the downhole low-side intake.

58. The downhole low-side intake of any one of claims 1 - 57 with a pump motor shroud coupled in an uphole direction of the downhole low-side intake.

59. The downhole low-side intake of any one of claims 1 - 58 installed as or coupled to a liner in a wellbore.

60. The downhole low-side intake of claim 59 in which: the liner defines a liner receptacle that defines a bore; and a production tubing string is installed, with a pump intake of a downhole pump hydraulically coupled to an outlet of the downhole end of the liner.

61. The downhole low-side intake of claim 60 in which a packoff is installed in the bore to provide a hydraulic coupling.

62. The downhole low-side intake of any one of claims 60 - 61, in which a non-sealing restriction is achieved at a packoff between the production string and the liner of the downhole low-side intake.

63. The downhole low-side intake of any one of claims 60 - 62, in which: a packoff is located above the pump intake; an intake stage of the downhole low-side intake is downhole of the pump intake; and flow inside the downhole low-side intake is primarily in an uphole direction.

64. The downhole low-side intake of any one of claims 60 - 63, in which:a packoff is located below the pump intake; an intake stage of the downhole low-side intake is uphole of the pump intake; and flow inside the downhole low-side intake is primarily in a downhole direction.

65. The downhole low-side intake of any one of claims 60 - 64 in which: intake stages of the downhole low-side intake are both downhole and uphole of the pump intake; and the downhole low-side intake is configured such that flow inside portions of the downhole low-side intake is in a downhole direction and flow inside other portions of the low-side intake is in an uphole direction.

66. The downhole low-side intake of any one of claims 60 - 65 in which an intake stage of the downhole low- side intake is oriented manually during installation, the orientation being measured during the installation process.

67. The downhole low-side intake of claim 66 further comprising a pump receptacle, in which a production tubing string comprising a downhole pump is installed in the wellbore, with an intake of the downhole pump hydraulically coupled to an outlet of the downhole low-side intake.

68. A liner comprising the downhole low-side intake of any one of claims 1 - 67.

69. A production string comprising the downhole low-side intake of any one of claims 1 - 67.

70. A multi-stage downhole low-side intake for a downhole pump comprising a plurality of the downhole low- side intakes of any one of claims 1 - 67 coupled together.

71. A method comprising using the downhole low-side intake of any one of claims 1 - 67 to produce fluids from a wellbore.

72. The downhole low-side intake of any one of claims 1 - 67 installed at an inclination between 45 and 100 degrees.

73. A downhole low-side intake comprising: a wellbore liner; an intake with low-side oriented inlet openings uphole of a plug or bullnose; and a pump receptacle or pump connector at a downstream end of the wellbore liner.

74. The downhole low-side intake of claim 73 in which the plug or bullnose is toward or at a downhole end of the wellbore liner.

75. An articulating downhole swivel that is configured to allow free rotation of an eccentrically weighted downhole low-side intake coupled thereto, and to allow relative movement to cause angular misalignment of axes of the downhole low-side intake and a tubular located uphole of the swivel.

76. The articulating downhole swivel of claim 75 configured with a non-zero distance of misalignment between an axis of an inner housing of the low-side intake and an axis of an overlapping portion of the articulating downhole swivel.

77. A downhole low-side intake with a flexible connection between intake stages.

78. The downhole low-side intake of claim 77 in which the flexible connection comprises a flex joint that is configured to not seal, and in which an external eccentric baffle is located within close proximity in downhole direction from the flex joint, and a non-permeable portion of a baffle covers a high-side above the flex joint.

79. A downhole low-side intake comprising a tubular, which is eccentrically weighted by having one longitudinal edge rolled inside another longitudinal edge to form an overlapping portion that is sealed together toallow rotation of the downhole low-side intake within the wellbore to align one or more inlet openings in the tubular toward a low-side of the wellbore.

80. A multi-stage downhole low-side intake comprising: an outer housing; a plurality of intake stages that each: are formed of a tubular within the outer housing and are separated from adjacent intake stages by external crosswise baffles; have inlet openings distributed circumferentially around the tubular; have openings in the outer housing defining a permeable portion; and have an eccentrically weighted baffle that defines a baffle inlet opening and is configured to rotate relative to the tubular to orient the baffle inlet opening toward a low-side of the wellbore.

81. The multi-stage downhole low-side intake of claim 80 in which, for one or more of the plurality of intake stages, the eccentrically weighted baffle is configured to substantially cover the inlet openings of the tubular and permit flow into a low-side-oriented inlet opening, or portion thereof, of the inlet openings of the tubular.

82. The multi-stage downhole low-side intake of any one of claims 80 - 81 in which, for one or more of the plurality of intake stages, the tubular and the outer housing are arranged concentrically relative to one another.

83. The multi-stage downhole low-side intake of any one of claims 80 - 82 in which, for one or more of the plurality of intake stages, the low-side-oriented inlet opening is oriented to permit axial flow in a downhole direction within an annulus between the tubular and the outer housing.

84. The multi-stage downhole low-side intake of any one of claims 80 - 83 in which one or more of: the inlet openings define a strainer or fdter; or a strainer or filter is coupled to the eccentrically weighted baffle.

85. The multi-stage downhole low-side intake of any one of claim 80 - 84 in which: an annular gas separation chamber is defined between the permeable portion of the outer housing and the eccentrically weighted baffle; and a strainer or filter is within the annular gas separation chamber.

86. The multi-stage downhole low-side intake of any one of claims 80 - 85 in which fluid flow paths of the intake stages connect in parallel to collectively pass fluids from the intake stages downstream.

87. The multi-stage downhole low-side intake of any one of claims 80 - 86 in which a rotatable thru-shaft part extends between downstream and upstream ends of the multi-stage downhole low-side intake.

88. The multi-stage downhole low-side intake of any one of claims 80 - 87 in which, for one or more of the plurality of intake stages, the intake stage comprises one or more impellers that are structured to convey fluid from a separation chamber of the intake stage, through inlet openings, and into an inner common fluid flow path of the intake stage, the tubular defining the inner common fluid flow path comprising diffusers, couplers, and tubular sleeves axially compressed within the outer housing.

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