Screw hub with improved two-phase separation

Abstract

Pumping of wellbore fluids to the surface can have an adverse effect on pump performance due to high gas concentrations in the fluids. The present disclosure provides a pump system utilizing a helical gas separator that provides higher pump efficiency by effectively removing the gas phase of the fluids. The wellbore fluids received at the pump system are directed from an intake to a gas separator utilizing a stationary helical auger. The stationary helical auger induces rotational motion of the wellbore fluids, separating the wellbore fluids into a gas phase and a liquid phase. The stationary helical auger utilizes a decreasing diameter and openings between one or more helixes or vanes to more efficiently separate the gas phase from the liquid phase of the fluids.

Description

[0001] Cross Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 181,602, filed April 29, 2021, and U.S. Non-Provisional Application No. 17 / 354,535, filed June 22, 2021, both of which are incorporated by reference in their entirety.

[0003] TECHNICAL FIELD

[0004] The present disclosure relates generally to the separation of gas and liquid phases of downhole fluids, and more particularly to a gas separator system that induces fluid rotation of fluids in a wellbore. BACKGROUND

[0005] Hydrocarbons, such as oil and gas, are produced or obtained from subterranean reservoir formations that can be located on land or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from subterranean formations generally involve many different steps, such as drilling a wellbore at a desired wellsite, treating the wellbore to optimize production of hydrocarbons, performing necessary steps to produce hydrocarbons from the subterranean formation, and pumping the hydrocarbons to the surface of the earth.

[0006] When performing subterranean operations, a pump system, such as an electric submersible pump (ESP) system, can be used when reservoir pressure is insufficient to produce hydrocarbons from the well. The presence of gas or free gas in the fluid of the reservoir or wellbore and the resulting multiphase flow behavior of the fluid has an adverse effect on pump performance and pump system cooling. Economical and efficient pump operation can be affected by the gas-containing fluid. The presence of gas in the pump results in a drop in pressure generated within the pump stages, thereby reducing the output of the pump. High concentrations of gas within the pump can create a condition commonly referred to as “gas lock,” where gas is very prominent at each stage of the pump and the expected production fluid no longer reaches the surface. Separation of gas from the liquid phase of the fluid prior to entering the pump improves pump performance, reduces pump vibration, and lowers the operating temperature of the pump. Conventional rotational and vortex gas separators rely on rotating components to separate the two phases, a process that is limited by fluid velocity, while requiring an increase in system horsepower demand and increasing the likelihood of erosion within the separation chamber. Erosion, which varies with particle velocity as the particles contact the rotating paddles in conventional vortex and rotational separator systems, cuts through the separation chamber walls and housing, thereby splitting the downhole pump string. There is a need for an effective, efficient, and reliable pump gas separation system. BRIEF DESCRIPTION OF DRAWINGS

[0007] FIG. 1 is an illustrative well environment in accordance with one or more aspects of the present disclosure.

[0008] FIG. 2is an illustrative pump system in accordance with one or more aspects of the present disclosure.

[0009] FIG. 3 is an illustrative gas separator of a pump system in accordance with one or more aspects of the present disclosure. FIG. 2 is an illustrative gas separator of a pump system in accordance with one or more aspects of the present disclosure.

[0010] FIG. 4 is a flow diagram illustrating a method of separating fluid using a gas separator in accordance with one or more aspects of the present disclosure. FIG. 3

[0011] While embodiments of the present disclosure have been depicted, described, and defined in reference to exemplary embodiments of the present disclosure, such reference does not imply a limitation on the present disclosure, and is not intended to limit the present disclosure in any way. The disclosed subject matter supports numerous modifications, alterations, and equivalent variations, in form and function, as will become apparent to those skilled in the relevant art. The depicted and described embodiments of the present disclosure are only examples, and are not exhaustive of the scope of the present disclosure. DETAILED DESCRIPTION

[0012] Conventional gas separators require rotating or moving components or elements to impart or induce rotational flow of downhole fluid to separate different phases of the downhole fluid such that the pump receives only the liquid phase of the downhole fluid. However, moving components or elements suffer from wear and tear and increase the overall cost of the system. In accordance with one or more embodiments of the present disclosure, the gas separator of the pump system utilizes fewer moveable components to provide efficient separation of the gas and liquid phases of the downhole fluid. For example, a stationary auger induces fluid rotation of the downhole fluid and centrifugal separation of the gas and liquid phases. The stationary auger serves as the primary means of inducing fluid rotation. Since the separator utilizes a stationary auger, the flow rate of the separator is not limited by the downhole fluid moving device as a high flow fluid moving device can be utilized and is not limited by rotating separation elements as the inducer is static. The gas separator is mechanically simpler and more efficient compared to conventional gas separators used in pump systems such as ESP systems.

[0013] ​A gas separator, such as a spiral gas separator, in accordance with one or more embodiments of the present disclosure utilizes a stationary spiral auger as the primary device to induce rotation of fluids received from a wellbore. The spiral gas separator includes a housing, an intake at one end of the housing, a discharge or cross-over at the opposite end of the intake that can be coupled to a pump, a stationary spiral auger disposed or positioned inside the housing, a space or mechanism for allowing a rotating shaft to pass through the center of the housing, a fluid moving device or mover, and any one or more other separation components or supports within the housing. Fluids received from the wellbore are forced into the intake by fluid pressure, moving into the fluid moving device. The fluid moving device causes a flow of the fluid stream to flow through the stationary spiral auger, which induces rotational motion of the fluid by the fluid's interaction with one or more blades of the stationary spiral auger in a separation chamber. As a result, the gas phase of the fluid moves to the inside of the separation chamber and exits to the wellbore through the cross-over and discharge at the discharge end of the spiral gas separator. The liquid phase moves to the outside of the separation chamber and into the intake of the pump through the discharge end of the separator. The spiral gas separator is more efficient because it has fewer moving parts and the rotational motion is induced by the moving fluid's interaction with the stationary spiral auger. The intake and stationary spiral auger flow passages are designed such that the pressure drop across the intake and spiral auger flow passages is less than the pressure drop across the cross-over and discharge. The fluid moving device is used with the gas separator to prevent fluid from being drawn into the spiral gas separator through the discharge.

[0014] The spiral gas separator of the present disclosure provides efficient and economical separation of gas from gas-containing fluids, such as one or more downhole fluids associated with hydrocarbon recovery or production operations. Conventional rotary and vortex separator designs include many moving parts, and these moving parts are subject to one or more abrasive downhole materials, such as sand. Contact with such abrasive materials causes erosion of the moving parts. In accordance with one or more embodiments, the spiral gas separator reduces wear and tear due to erosion by utilizing a stationary spiral auger, which minimizes the number of moving parts, reducing maintenance and replacement costs. Additionally, the intake and stationary spiral auger flow passages are configured such that the pressure drop across them is less than the pressure drop across the cross-over and exit, and / or a fluid moving device is used within the gas separator and positioned between the separator intake and the stationary spiral auger to prevent fluid from being drawn into the separator through the exit. Furthermore, the use of a stationary spiral auger as the separation inducer enables the use of a high flow fluid moving device, which results in higher flow rates achievable through the gas separator. The use of a stationary spiral auger enhances the separation of the gas and liquid phases from the wellbore fluid due to the increased flow rate.

[0015] Illustrative embodiments of the application are described in detail below with reference to the attached drawing figures. For the purposes of clarity and the ease of understanding, not all of the features of an actual implementation can be described in this specification. It will be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions can be made to achieve the specific implementation goals, which 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 this disclosure.

[0016] Throughout this disclosure, reference to a reference sign followed by a letter character refers to a particular instance of an element, and reference signs alone generically refer or collectively refer to the element. Thus, by way of example (not shown in the figures), the reference sign "la" refers to an instance of the reference sign class, which can be collectively referred to as the reference sign "1" and any one of which can generically refer to the reference sign "1". In the figures and the description, like reference signs are intended to represent like elements.

[0017] To facilitate a better understanding of the present disclosure, the following examples of certain embodiments are given. The following embodiments are in no way to be understood as limiting or defining the scope of the present disclosure. Embodiments described below in relation to one implementation are not intended to be limiting.

[0018] As used herein, the term "coupled" is intended to mean an indirect or direct connection. Thus, if a first device is coupled to a second device, that connection can be through a direct electrical connection, or through an indirect electrical connection or via other devices and connections.

[0019] FIG. 1 An example of a wellsite environment 100 in accordance with one or more aspects of the present disclosure is shown. While the wellsite environment 100 shows a land-based subterranean environment, the present disclosure contemplates any wellsite environment including a subsea environment. In one or more embodiments, any one or more components or elements can be used with subterranean operating equipment located on offshore platforms, drilling ships, semi-submersible submersibles, drilling barges, and land-based drilling rigs. In one or more embodiments, the wellsite environment 100 includes a wellbore 104 in a formation 124 below a surface 102. In one or more embodiments, the wellbore 104 can include a unconventional, horizontal, or any other type of wellbore. The wellbore 104 can be partially defined by a casing string 106, which can extend from the surface 102 to a selected downhole location. The portion of the wellbore 104 not including the casing string 106 can be referred to as the open hole.

[0020] In one or more embodiments, a pump system 150 disposed or positioned downhole (e.g., within, partially within, or outside of a casing 106 of the wellbore 104) can be used to pump various types of hydrocarbons or fluids from the wellbore 104 to the surface 102. In one or more embodiments, the pump system 150 can include an electric submersible pump (ESP) system. The pump system 150 can include a pump 108, a cable 110, a separator 112, a seal or equalizer 114, a motor 116, and a sensor 118. The pump 108 can be an ESP, including but not limited to a multi-stage centrifugal pump, a rod pump, a progressive cavity pump, any other suitable pump system, or a combination thereof. The pump 108 can impart pressure to the fluid 126 or any other type of downhole fluid to push the fluid from downhole to the surface 102 at a desired or selected pumping rate. The pump 108 is coupled to the gas separator 112. The gas separator 112 is coupled to the seal or equalizer 114, which is coupled to the motor 116. The motor 116 can be coupled to the downhole sensor 118. In one or more embodiments, the cable 110 is coupled to the motor and to a controller 120 at the surface 102. The cable 110 can provide power to the motor 116, transmit one or more control or operational instructions from the controller 120 to the motor 116, or both.

[0021] In one or more embodiments, the fluid 126 can be a multiphase wellbore fluid containing one or more hydrocarbons. For example, the fluid 126 can include a gas phase and a liquid phase from the wellbore or reservoir in the formation 124. In one or more embodiments, the fluid 126 can enter the wellbore 104, the casing 106, or both, through one or more perforations 130 in the formation 124 and flow uphole to one or more intake ports of the pump system 150. The pump 108 can impart pressure to the fluid 126 by adding kinetic energy to the fluid 126 via centrifugal force and converting the kinetic energy to potential energy in the form of pressure. In one or more embodiments, the pump 108 lifts the fluid 126 to the surface 102.

[0022] Fluid pressure in the wellbore 104 causes the fluid 126 to enter the gas separator 112. The gas separator 112 separates a gas phase or gas component of the fluid 126 from a liquid phase before the gas phase enters the pump 108. In one or more embodiments, the motor 116 is an electric submersible motor configured or operable to turn the pump 108, and can be, for example, a two-pole, three-phase squirrel cage induction motor or any other motor operable or configurable to turn the pump 108. The seal or equalizer 116 can be a motor protector that functions to equalize pressure and keep motor oil separate from the fluid 126. In one or more embodiments, the production tubing section 122 can be coupled to the pump 108 using one or more connectors 128, or can be directly coupled to the pump 108. In one or more embodiments, any one or more production tubing sections 122 can be coupled together to extend the pump system 150 into the wellbore 104 to a desired or designated location. Any one or more components of the fluid 126 can be pumped from the pump 108 through the production tubing 122 to the surface 102 for transfer to a storage tank, pipeline, transport vehicle, any other reservoir, distribution or transportation system, and any combination thereof.

[0023] FIG. 2 is an illustrative pump system 150 according to one or more aspects of the present disclosure. A shaft can extend through one or more components or elements of the pump system 150 in order to couple one or more components to one or more other components. The shaft can transmit or convey rotation of the motor 116 to one or more components or elements of the gas separator 112. Any one or more components can be coupled via a coupling 206. The gas separator 112 can include a housing 212. One or more inlet ports 202 can be disposed or positioned at a distal end 214 of the housing 212, and one or more outlet ports 204 can be disposed or positioned at a proximal end 216 of the housing 212. In one or more embodiments, the one or more inlet ports 202 and the one or more outlet ports 204 can be disposed or positioned circumferentially around the gas separator 112 at the downhole or distal end 214 and the uphole or proximal end 216, respectively, of the gas separator 112. The one or more inlet ports 202 allow the fluid 126 (refer to FIG. 1 ) to enter the gas separator 112. The one or more outlet ports 204 allow the gas phase or gas component of the fluid 126 to exit into the annulus 210 of the casing 106 or wellbore 104.

[0024] FIG. 3 is a partial cross-sectional view of an illustrative gas separator 112 of the pump system 150 (refer to FIG. 1 ) according to one or more aspects of the present disclosure. The gas separator 112 can be coupled to one or more other components, such as to the pump 108 (refer to FIG. 1). In one or more embodiments, the shaft 318 passes through any one or more of the couplings 206. The gas separator 112 can be disposed or positioned within, coupled to, or otherwise associated with an outer housing 312 of the downhole tool or system. In one or more embodiments, the outer housing 312 can include or act as the housing 212 of FIG. 2 . The gas separator 112 can include the fluid mover 310, the stationary auger 302, and one or more discharge ports 314 and 316. The fluid mover 310 can be any type of fluid mover, such as a rotating auger, an impeller, an impeller and diffuser system, or any other type of fluid mover. The fluid mover 310 can include or be coupled to one or more intake ports 202 disposed or positioned circumferentially around a distal end of the fluid mover 310. The one or more intake ports 202 allow the fluid 126 from the annulus 210 to enter into the fluid mover 310, which conveys or flows the fluid 126 to the stationary auger 302. In one or more embodiments, the rotating shaft 304 can extend through or can be the same as the shaft 318. The rotating shaft 304 can be driven by the motor 116 (refer to FIG. 1 ). For example, the rotating shaft 304 can rotate when the motor 116 is energized, such as by a command from the controller 120 (refer to FIG. 1 ) transmitted to the motor 116 via the electrical cable 110 (refer to FIG. 1 ). The rotating shaft 304 extends through the fluid mover 310 and the stationary auger 302 to drive the pump 108 coupled to the gas separator 112. In one or more embodiments, the fluid mover 310 is coupled to the rotating shaft 304 and the motor 116.

[0025] In one or more embodiments, the stationary auger 302 is disposed or positioned within the separation chamber 330. The fluid mover 310 can be coupled to the separation chamber 330 at a downhole or distal end of the separation chamber 330. In one or more embodiments, the stationary auger 302, the separation chamber 330, or both are fluidly coupled to the one or more intake ports 202. For example, the separation chamber 330, the stationary auger 302, or both can be coupled to the fluid mover 310 via a support or other device, including but not limited to the rotating shaft 304. The fluid mover 310 conveys or forces fluid 126 received at the one or more intake ports 202 through the separation chamber 330, the stationary auger 302, or both. In one or more embodiments, the stationary auger 302 is coupled to the sleeve 322 such that the sleeve 322 maintains the stationary auger 302 in a stationary, non-rotating position. The sleeve 322 can be disposed or positioned within the separation chamber 330 or the outer housing 312. In embodiments, the rotating shaft 304 can rotate within the stationary auger 302 while the stationary auger 302 remains in a stationary, non-rotating position.

[0026] In one or more embodiments, the stationary auger 302 includes one or more augers or vanes 324. Without limitation, any suitable number of augers or vanes 324 can be used in accordance with the present disclosure. In one or more embodiments, the augers or vanes 324 can be crescent shaped. In one or more embodiments, the stationary auger 302 includes one or more augers or vanes 324 disposed about an open core (e.g., a coreless auger or auger vane). The stationary auger 302 can separate the fluid 126 into the liquid phase 308 and the gas phase 306 based at least in part on the rotational flow of the fluid 126. For example, as the fluid 126 flows through, across, or around the one or more augers or vanes 324, the one or more augers or vanes 324 can impart rotation to the fluid 126. For example, the fluid mover 310 forces the fluid 126 into the separation chamber 330 and across or up to the one or more augers or vanes 324 of the stationary auger 302 at a velocity or flow rate.

[0027] The rotation of the fluid 126 induced by the stationary auger 302 can be based at least in part on the velocity or flow rate of the fluid 126 from the fluid mover 310. For example, the fluid mover 310 can increase the flow rate or velocity of the fluid 126 to increase the rotation of the fluid 126 through the stationary auger 302 to produce a more efficient and effective separation of the fluid 126 into the plurality of phases (e.g., the liquid phase 308 and the gas phase 306). As the fluid 126 flows through the stationary auger 302, centrifugal force, static friction, or both cause the heavier components of the fluid 126 (the liquid phase 308) to circulate along the outer periphery of the stationary auger 302, while the lighter components of the fluid 126 (the gas phase 306) circulate along the inner periphery of the stationary auger 302. In one or more embodiments, the fluid 126 can begin to separate into the gas phase 306 and the liquid phase 308 while flowing through the fluid mover 310 and can continue to separate while flowing through the stationary auger 302. In one or more embodiments, the liquid phase 308 can include residual gas that does not separate into the gas phase 306. However, the embodiments discussed herein minimize this residual gas to protect the pump 108 from gas accumulation or gas lock. In one or more embodiments, the induced vortex in the separation chamber 330 can aid in the separation of the fluid 126 into the gas phase 306 and the liquid phase 308.

[0028] In one or more embodiments, the separated fluids (e.g., the liquid phase 308 and the gas phase 306) are directed to the inlet 350 of the cross, where the cross is configured to direct the liquid phase 308 and the gas phase 306 away from the stationary auger 302. For example, the inlet 350 of the cross can be disposed or positioned at the well or proximal end of the separation chamber 330 or the outer housing 312. For example, the inlet 350 of the cross can fluidly couple the separation chamber 330 or otherwise direct one or more components or phases of the fluid 126 to the pump 108 and subsequently to the annulus 210. The cross can include a plurality of passages, such as a gas phase outlet 314 (a first path) and a liquid phase outlet 316 (a second path). The gas phase 306 of the fluid 126 can be expelled through the gas phase outlet 314, and the liquid phase 308 of the fluid 126 can be expelled through the liquid phase outlet 316. In one or more embodiments, the gas phase outlet 314 can correspond to any one or more of the outlets 204 of FIG. 2. In one or more embodiments, any one or more of the gas phase outlet 314 and the one or more liquid phase outlets 316 can be defined by a passage or path having an opening, such as a teardrop-shaped opening. In certain embodiments, the separation chamber 330 can aid in directing the gas phase 306 and the liquid phase 308 to the gas phase outlet 314 and the liquid phase outlet 316, respectively. FIG. 2

[0029] ​In one or more embodiments, gas separator 112 can employ an inverted Venturi principle, where the pressure of fluid 126 can increase as it passes through stationary auger 302. Gas separator 112 can enhance two-phase fluid separation characteristics by increasing the flow area, which allows the gas phase 306 of fluid 126 to better separate from the liquid phase 308. The combination of radial and centrifugal forces with axial velocity can be enhanced by opening the flow area with one or more augers or vanes 324. In embodiments, stationary auger 302 can include a hub 332, where hub 332 can generally be a cylindrical hollow shaft, where one or more augers or vanes 324 can be disposed on or around hub 332. As shown, the diameter of hub 332 can taper toward the proximal end of stationary auger 302. Hub 332 includes a first end 334 and a second end 336 opposite first end 334. Rotating shaft 318 can pass through hub 332. Hub 332 of auger 302 can protect shaft 318 from fluid 126 and separate well fluid 126 from any rotational velocity from shaft 318. As shown, the outer diameter of hub 332 at first end 334 can be greater than the outer diameter of hub 332 at second end 336, creating a tapering diameter of hub 332. In one or more embodiments, one or more augers or vanes 324 disposed around first end 334 can be disposed at a different angle relative to the central or vertical axis of hub 332 than one or more augers or vanes 324 disposed around second end 336. For example, those disposed around first end 334 can include an angle of “A°”, while those disposed around second end 336 can include an angle of “B°”. Without limitation, the angle of one or more augers or vanes 324 disposed around first end 334 (e.g., angle A) can be from about 20° to about 70°. Without limitation, the angle of one or more augers or vanes 324 disposed around second end 336 (e.g., angle B) can be from about 20° to about 70°. In embodiments, angle A° can be equal to or greater than angle B°. The present disclosure is not limited to such example angles, and any suitable angle can be used for one or more augers or vanes 324. The angle of one or more augers or vanes 324 disposed around first end 334 can be associated with the direction of fluid 126 exiting from fluid mover 310 below, and the angle of one or more augers or vanes 324 disposed around second end 336 can allow for efficient transfer of gas phase 306 and liquid phase 308 into the flow path to the inlet 350 of the cross-over. In further embodiments, the angle of one or more augers or vanes 324 closest to the inlet 350 of the cross-over can be designed to improve the efficiency of the discharge of gas phase 306 and liquid phase 308.

[0030] In one or more embodiments, there can be openings 338 disposed between the one or more spirals or vanes 324 and the hub 332. As shown, the cross-sectional area of the openings 338 can increase as the one or more spirals or vanes 324 approach the second end 336. For example, there can be no openings 338 for a first of the one or more spirals or vanes 324, but as the one or more spirals or vanes 324 are disposed along the length of the hub 332, the openings 338 can begin and increase in shape and size closer to the second end 336 of the hub 332. The openings 338 can be locations where the one or more spirals or vanes 324 are unattached or detached from the hub 332. In embodiments, the openings 338 can allow gas within the fluid 126 to decompose into the gas phase 306 and provide a path for the gas phase 306 to flow to the gas phase exit 314. The increased pressure resulting from the larger surface area of the openings 338 can aid in the gas phase 306 escaping the gas phase exit 314. The inner diameter of the one or more spirals or vanes 324 can increase from the first end 334, leaving a radial void (e.g., the openings 338) between the outer diameter of the hub 332 and the inner diameter of the one or more spirals or vanes 324. In embodiments, this can create a fixed space for gas to separate and begin moving upward from the fluid 126 between the first end 334 and the second end 336. In one or more embodiments, the openings 338 can begin at about a middle or center location along the length of the hub 332. In one or more embodiments, the outer diameter of the one or more spirals or vanes 324 can be coupled to the sleeve 322. In further embodiments, as the cross-sectional area of the openings increases along the length of the hub 332, the size, shape, cross-sectional area of the openings 338, and combinations thereof, can further increase as a result of the tapering diameter of the hub 332. As shown, the openings 338 can be a breakaway of the one or more spirals or vanes 324 located at least partially at the second end 336.

[0031] In one or more embodiments, the fluid mover 310 can receive the fluid 126 through the one or more intake ports 202. In one or more embodiments, the fluid mover 310 can include a rotating auger, where the fluid mover 310 includes an auger sleeve disposed or positioned within the fluid mover 310 in a circumferential direction. The rotating auger can be disposed or positioned within the auger sleeve such that the rotating auger is free to rotate within the auger sleeve. As the motor 116 causes the rotating auger to rotate, the fluid 126 is drawn into the fluid mover 310 through the one or more intake ports 202 and into the separation chamber 330 where the fluid 126 is separated into different phases.

[0032] In one or more embodiments, the fluid mover 310 can include one or more impellers and / or one or more diffusers. While the fluid mover 310 can include one or more impellers and / or one or more diffusers, the present disclosure contemplates any type of fluid mover. The fluid 126 moving into the fluid mover 310 can contain multiple phases, such as a gas phase and a liquid phase. These phases can mix together, merge, or otherwise substantially not separate at the one or more inlet ports 202 to become, for example, the fluid 126 as illustrated. The fluid mover 310 can cause the received fluid 126 to flow through the fluid mover 310 at a flow rate or velocity. The fluid 126 can be forced or flow into the separation chamber 330 at a flow rate or velocity that is based at least in part on the rotation of the one or more impellers. In one or more embodiments, as the velocity or flow rate increases, the fluid 126 can begin to separate in the fluid mover 310, while in one or more other embodiments, the fluid 126 can remain substantially or partially mixed. The fluid 126 can enter the separation chamber 330 and be forced to flow through, across, around, or about the one or more blades or spirals 324 of the stationary auger 302.

[0033] As the fluid 126 flows through the stationary auger 302, for example, in an induced rotational flow pattern, the fluid 126 can begin to separate into a gas phase 306 and a liquid phase 308. The gas phase 306 can contain all or substantially all of the gas from the fluid 126, and the liquid phase 308 can contain all or substantially all of the liquid from the fluid 126. Centrifugal force, static friction, or both cause the heavier liquid phase 308 to travel along the outer periphery of the stationary auger 302, while the lighter gas phase 306 can flow along the inner periphery or closer to the center of the stationary auger 302 within the opening 338 between the hub 332 and the one or more spirals or blades 324. The greater the velocity or flow rate of the fluid 126, the better the separation of the fluid 126 into the gas phase 306 and the liquid phase 308.

[0034] As the gas phase 306 and the liquid phase 308 approach the inlet 350 of the intersection, each of the gas phase 306 and the liquid phase 308 are directed to different discharge outlets. In one or more embodiments, the gas phase 306 is directed to the gas discharge outlet 314 and the liquid phase 308 is directed to the liquid discharge outlet 316. For example, the pump 108 can create a pressure differential between the gas separator 112 and the annulus 210. The gas phase 306 naturally flows toward the lower pressure area or region. That is, the gas separator 112 is at a higher pressure compared to the annulus 210, which causes the gas phase 306 to naturally flow to the annulus 210. The intake of the pump 108 can be hydraulically and mechanically connected to the gas separator 112 and can receive the liquid phase 308. As discussed above, the liquid phase 308 can contain liquid and any residual gas that was not separated by the gas separator 112.

[0035] As the gas phase 306 and the liquid phase 308 come into contact with more surface area within the stationary auger 302 and the sleeve 322, the resistance to flow can be greater due to surface tension. In one or more embodiments, one or more portions of the stationary auger 302 can be coated with a friction-reducing agent, such as a plastic, including but not limited to a synthetic polymer, such as polytetrafluoroethylene. As the gas phase 306 and the liquid phase 308 circulate across or around the stationary auger 302, the gas phase 306 flows along the inner perimeter of the stationary auger 302, while the heavier liquid phase 308 flows along the outer perimeter of the stationary auger 302. As the gas phase 306 and the liquid phase 308 circulate across, through, or around the stationary auger 302, the separation between the two phases increases such that at the inlet 350 of the crossover, the gas phase 306 is discharged through the gas phase discharge outlet 314 or first path, while the liquid phase 308 is discharged through the liquid phase discharge outlet 316 or second path. In this way, the portion of the fluid 126 that is discharged to the pump 108 is substantially liquid (the liquid phase 308), such that the pump 108 is not adversely affected by the gas (the gas phase 306) of the fluid 126.

[0036] FIG. 4 is a flow diagram illustrating a method 400 for separating a fluid 126 (referenced FIG. 1 ) using a pump system 150 (referenced FIG. 1 ) in accordance with one or more aspects of the present disclosure. At step 402, the pump system 150 is positioned or disposed in a wellbore 104 (referenced FIG. 1 ) where the pump system 150 includes a gas separator 112 (referenced FIG. 1 ). In one or more embodiments, the pump system 150 can be included with or part of a downhole tool. The pump system 150 can be positioned or disposed such that one or more portions of the pump system 150 are submerged in or otherwise proximate to the fluid 126.

[0037] At step 404, the motor 116 (referenced FIG. 1 ) is energized. Energizing the motor 116 causes the rotating shaft 304 (referenced FIG. 3 ) to rotate. Rotation of the shaft 304 drives the pump 108 (referenced FIG. 1 ). At step 406, the pump 108 is actuated based on the motor 116 and the rotating shaft 304. Actuation of the pump 108 decreases the pressure at one or more intake ports 202 (referenced FIG. 2 ) such that at step 408, fluid in the wellbore 104 (e.g., the fluid 126) is directed, caused to move, or flows into the one or more intake ports 202 and into the fluid mover 310 (referenced FIG. 3 ) of the gas separator 112.

[0038] In step 410, fluid 126 is allowed to flow from fluid mover 310 to separation chamber 330 of gas separator 112 (reference). FIG. 3 For example, forcing fluid 126 through fluid mover 310 and into separation chamber 330, for example, as described above relative to... FIG. 3 As discussed. In step 412, as the fluid 126 travels through the separation chamber 330, a fixed helical actuator 302 (see reference) is positioned or located within the separation chamber 330. FIG. 3 This causes fluid 126 to become gaseous phase 306 (reference). FIG. 3 ) and liquid phase 308 (reference) FIG. 3 The separation of the gas phase 306 and the liquid phase 308 is lighter and occurs along one or more blades 324 of the fixed helical conveyor 302 (see reference). FIG. 3 The heavier liquid phase 308 travels along the inner periphery of one or more blades 324 of the fixed helical conveyor 302, while the heavier liquid phase 308 travels along the outer periphery of one or more blades 324 of the fixed helical conveyor 302. In an embodiment, the gas phase 306 may travel along the inner periphery of the hub 332 (reference 302). FIG. 3 The opening 338 between the 324 and one or more helices or blades 324 (reference) FIG. 3 The liquid phase 308 can travel within the outer periphery of the fixed screw conveyor 302, such that the liquid phase 308 contacts the sleeve 322 of the separation chamber 330 (see reference). FIG. 3 ).

[0039] In step 414, via the intersection (reference) FIG. 3 One or more gas phase outlets 314 (reference) of inlet 350 FIG. 2 The gas phase 306 is discharged from the separation chamber 330 and discharged through one or more liquid phase discharge ports 316 of the inlet 350 (see reference). FIG. 1 Liquid phase 308 is discharged from separation chamber 330. In one or more embodiments, gas phase 306 is discharged into annulus 210 (reference). FIG. 1 In one or more embodiments, liquid phase 306 is discharged to pump 108 via one or more liquid phase outlets 316, and pump 108 is, for example, via conduit 122 (see reference). ​ The liquid phase 308 is pumped to surface 102 (reference). ​ In step 416, the pump system 150 can be removed from the wellbore 104, and method 400 can continue to the end.

[0040] According to one or more aspects of the present disclosure, the pump system 150 improves the two-phase separation efficiency of a conventional spiral design by reducing the hub diameter in a tapering fashion and decoupling the spiral vanes 324 from the openings 338 from the hub 332 during the fluid flow process as the fluid flow traverses the final path of the spiral 324. This design improves the separation efficiency of the overall system by virtue of the increased radial area for the liquid phase 308 and the increased axial area for the gas phase 306.

[0041] An embodiment of the present disclosure is a gas separator for separating downhole fluids, the gas separator comprising: an inlet, wherein the inlet is configured to receive a downhole fluid; a fluid mover fluidly coupled to the inlet; and a fixed spiral auger fluidly coupled to the fluid mover, wherein the fixed spiral auger separates the downhole fluid into a gas phase and a liquid phase based at least in part on the downhole fluid. The fixed spiral auger comprises: a hub, wherein the hub comprises a tapering diameter, wherein the tapering diameter of the hub is configured such that the diameter at a first end is greater than the diameter at a second end; one or more spirals or vanes disposed about the hub; and an opening disposed between a portion of the one or more spirals or vanes, wherein the opening is a decoupling of the one or more spirals or vanes at the second end. The gas separator further comprises: a first path fluidly coupled to the fixed spiral auger, wherein the gas phase is directed through the first path; and a second path fluidly coupled to the first path, wherein the liquid phase is directed through the second path.

[0042] In one or more embodiments described in the preceding paragraph, wherein an angle of the one or more spirals or vanes disposed about the first end of the hub is selected from a range of about 20° to about 70°. In one or more embodiments described above, wherein an angle of the one or more spirals or vanes disposed about the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed about the first end of the hub is greater than the angle of the one or more spirals or vanes disposed about the second end of the hub relative to a central axis of the hub. In one or more embodiments described above, wherein the fluid mover comprises an impeller, an impeller with a diffuser, or a rotating spiral auger. In one or more embodiments described above, further comprising a separation chamber, wherein the separation chamber is fluidly coupled to the fixed spiral auger and the fixed spiral auger is disposed within the separation chamber. In one or more embodiments described above, further comprising a sleeve coupled to the fixed spiral auger, wherein the sleeve maintains the fixed spiral auger in a non-rotating position. In one or more embodiments described above, further comprising a rotating shaft, wherein the rotating shaft passes through the fixed spiral auger to a pump.

[0043] Another embodiment of the present disclosure is a method of separating a fluid into a plurality of phases, the method comprising: receiving the fluid at an inlet; flowing the fluid through a stationary auger fluidly coupled to the inlet; inducing rotation of the fluid based at least in part on the stationary auger; separating the fluid into a liquid phase and a gas phase as the fluid flows through the stationary auger, wherein the gas phase is configured to separate into one or more spirals or vanes disposed between an opening of a hub disposed around the stationary auger and the hub, wherein the hub comprises a tapered diameter, wherein the tapered diameter of the hub is configured such that a diameter at a first end is greater than a diameter at a second end; discharging the gas phase through a first path, wherein the opening is a disengagement of the one or more spirals or vanes at the second end; and discharging the liquid phase through a second path.

[0044] In one or more embodiments described in the preceding paragraph, wherein an angle of the one or more spirals or vanes disposed around the first end of the hub is selected from a range of about 20° to about 70°. In one or more embodiments described above, wherein an angle of the one or more spirals or vanes disposed around the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed around the first end of the hub is greater than the angle of the one or more spirals or vanes disposed around the second end of the hub relative to a central axis of the hub. In one or more embodiments described above, further comprising: receiving the fluid from the inlet at a fluid mover; and forcing the fluid to flow to the stationary auger at a flow rate by the fluid mover, wherein the rotation of the fluid is based at least in part on the flow rate. In one or more embodiments described above, wherein the fluid mover comprises an impeller, an impeller with a diffuser, or a rotating auger. In one or more embodiments described above, further comprising maintaining the stationary auger in a fixed position using a sleeve coupled to the stationary auger. In one or more embodiments described above, wherein the gas phase is discharged through the first path into an annulus and the liquid phase is discharged through the second path to a pump.

[0045] Yet another embodiment of the present disclosure is a pump system comprising: a pump; and a gas separator coupled to the pump, wherein the gas separator comprises: an intake, wherein the intake is configured to receive a downhole fluid; a fluid mover fluidly coupled to the intake; a stationary auger fluidly coupled to the fluid mover, wherein the stationary auger separates the downhole fluid into a gas phase and a liquid phase based at least in part on the downhole fluid, wherein the stationary auger comprises: a hub, wherein the hub comprises a decreasing diameter, wherein the decreasing diameter of the hub is configured such that a diameter at a first end is greater than a diameter at a second end; one or more spirals or vanes disposed about the hub; and an opening disposed between a portion of the one or more spirals or vanes; a first path fluidly coupled to the stationary auger, wherein the opening is a break in the one or more spirals or vanes at the second end, wherein the gas phase is directed through the first path; and a second path fluidly coupled to the stationary auger, wherein the liquid phase is directed through the second path.

[0046] In one or more embodiments described in the preceding paragraph, wherein an angle of the one or more spirals or vanes disposed about the first end of the hub is selected from a range of about 20° to about 70°. In one or more embodiments described above, wherein an angle of the one or more spirals or vanes disposed about the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed about the first end of the hub is greater than the angle of the one or more spirals or vanes disposed about the second end of the hub relative to a central axis of the hub. In one or more embodiments described above, wherein the fluid mover comprises an impeller, an impeller with a diffuser, or a rotating auger, and wherein the pump comprises one of a rod pump or a screw pump. In one or more embodiments described above, wherein the stationary auger is coupled to a sleeve, wherein the sleeve maintains the stationary auger in a non-rotating position. In one or more embodiments described above, wherein the gas separator further comprises a separation chamber fluidly coupled to the intake, wherein at least one of the stationary auger is disposed within the separation chamber and the separation chamber is fluidly coupled to the stationary auger.

[0047] Unless otherwise indicated, the numerical parameters set forth in the specification and attached claims are approximations that can vary depending on the desired properties sought to be obtained by the embodiments of the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0048] Accordingly, the present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only as to a manner of modifying and practicing the present disclosure and are not intended to limit the scope of the disclosure encompassed by the present disclosure. Numerous other embodiments can be devised by those skilled in the art which will fall within the scope and spirit of the disclosure. Furthermore, all optional features not specifically disclosed are intended to be encompassed by the present disclosure. What is claimed as being new is:

Claims

1. A gas separator for separating downhole fluids, the gas separator comprising: an inlet port, wherein the inlet port is configured to receive a downhole fluid; a fluid mover fluidly coupled to the inlet port; a stationary auger fluidly coupled to the fluid mover, wherein the stationary auger separates the downhole fluid into a gas phase and a liquid phase based at least in part on the downhole fluid, wherein the stationary auger comprises: a hub, wherein the hub comprises a decreasing diameter, wherein the decreasing diameter of the hub is configured such that a diameter at a first end is greater than a diameter at a second end; one or more spirals or vanes disposed about the hub; and an opening disposed between a portion of the one or more spirals or vanes, wherein the opening is a disengagement of the one or more spirals or vanes at the second end; a first pathway fluidly coupled to the stationary auger, wherein the gas phase is directed through the first pathway; and a second pathway fluidly coupled to the first pathway, wherein the liquid phase is directed through the second pathway.

2. The gas separator of claim 1, wherein an angle of the one or more spirals or vanes disposed about the first end of the hub is selected from a range of about 20° to about 70°.

3. The gas separator of claim 2, wherein an angle of the one or more spirals or vanes disposed about the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed about the first end of the hub is greater than the angle of the one or more spirals or vanes disposed about the second end of the hub with respect to a central axis of the hub.

4. The gas separator of claim 1, wherein the fluid mover comprises an impeller, an impeller with diffuser, or a rotating auger.

5. The gas separator of claim 1, further comprising a separation chamber, wherein the separation chamber is fluidly coupled to the stationary auger and the stationary auger is disposed within the separation chamber.

6. The gas separator of claim 1, further comprising a sleeve coupled to the stationary auger, wherein the sleeve maintains the stationary auger in a non-rotating position.

7. The gas separator of claim 1, further comprising a rotating shaft, wherein the rotating shaft passes through the stationary auger to a pump.

8. A method of separating a fluid into a plurality of phases, the method comprising: receiving a fluid at an inlet port; flowing the fluid through a stationary auger fluidly coupled to the inlet port; inducing rotation of the fluid based at least in part on the stationary auger; separating the fluid into a liquid phase and a gas phase as the fluid flows through the stationary auger, wherein the gas phase is configured to separate into an opening disposed between one or more spirals or vanes disposed around a hub of the stationary auger and the hub, wherein the hub comprises a decreasing diameter, wherein the decreasing diameter of the hub is configured such that a diameter at a first end is greater than a diameter at a second end, wherein the opening is a disengagement of the one or more spirals or vanes at the second end; discharging the gas phase through a first path; and discharging the liquid phase through a second path.

9. The method of claim 8, wherein an angle of the one or more spirals or vanes disposed around the first end of the hub is selected from a range of about 20° to about 70°.

10. The method of claim 9, wherein an angle of the one or more spirals or vanes disposed around the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed around the first end of the hub is greater than the angle of the one or more spirals or vanes disposed around the second end of the hub relative to a central axis of the hub.

11. The method of claim 8, further comprising: receiving the fluid from the intake at a fluid mover; and forcing the fluid to flow to the stationary auger at a flow rate by the fluid mover, wherein the rotation of the fluid is based at least in part on the flow rate.

12. The method of claim 11, wherein the fluid mover comprises an impeller, an impeller and diffuser, or a rotating auger.

13. The method of claim 8, further comprising maintaining the stationary auger in a fixed position using a sleeve coupled to the stationary auger.

14. The method of claim 8, wherein the gas phase is discharged through the first path into an annulus and the liquid phase is discharged through the second path to a pump.

15. A pump system, comprising: a pump; and a gas separator coupled to the pump, wherein the gas separator comprises: an intake, wherein the intake is configured to receive a downhole fluid; a fluid mover fluidly coupled to the intake; a stationary auger fluidly coupled to the fluid mover, wherein the stationary auger separates the downhole fluid into a gas phase and a liquid phase based at least in part on the downhole fluid, wherein the stationary auger comprises: a hub, wherein the hub comprises a decreasing diameter, wherein the decreasing diameter of the hub is configured such that a diameter at a first end is greater than a diameter at a second end; one or more spirals or vanes disposed around the hub; and an opening disposed between a portion of the one or more spirals or vanes, wherein the opening is a disengagement of the one or more spirals or vanes at the second end. a first path fluidically coupled to the stationary auger, wherein the gas phase is directed through the first path; and a second path fluidically coupled to the stationary auger, wherein the liquid phase is directed through the second path.

16. The system of claim 15, wherein an angle of the one or more spirals or vanes disposed about the first end of the hub is selected from a range of about 20° to about 70°.

17. The system of claim 16, wherein an angle of the one or more spirals or vanes disposed about the second end of the hub is selected from a range of about 20° to about 70°, wherein the angle of the one or more spirals or vanes disposed about the first end of the hub is greater than the angle of the one or more spirals or vanes disposed about the second end of the hub relative to a central axis of the hub.

18. The system of claim 15, wherein the fluid mover comprises an impeller, an impeller and diffuser, or a rotating auger, and wherein the pump comprises one of a rod pump or a screw pump.

19. The system of claim 15, wherein the stationary auger is coupled to a sleeve, wherein the sleeve maintains the stationary auger in a non-rotating position.

20. The system of claim 15, wherein the gas separator further comprises a separation chamber fluidically coupled to the inlet port, wherein at least one of the stationary augers is disposed within the separation chamber and the separation chamber is fluidically coupled to the stationary auger.

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