Remote launch system and staging valve with bypass system for fracturing operations and related methods

Abstract

A staging valve system and method for staging an activation device from low pressure in a launching system to high pressure in a frac tree. The system includes first and second isolation valves connected between the launching system and the frac head of the frac tree, and a pressure isolation passageway between the isolation valves. A frac fluid bypass line fluidly connects one or more frac fluid supply lines to the pressure isolation passageway. A bypass valve in the connected supply line permits frac fluid flow to the frac head when open, and closes the connected supply line and diverts flow of the frac fluid from the closed supply line into the bypass line when closed. A bypass isolation valve in the bypass line prevents frac fluid flow in the bypass line when closed, and permits flow of the diverted frac fluid from the bypass line into the pressure isolation passageway when open, to launch the activation device with the diverted frac fluid from the pressure isolation passageway through the second isolation valve and the frac head, and into frac tree components below the frac head.

Description

[0001] REMOTE LAUNCH SYSTEM AND STAGING VALVE WITH BYPASS SYSTEM FOR FRACTURING OPERATIONS AND RELATED METHODS

[0002] TECHNICAL FIELD

[0003] This disclosure relates to hydrocarbon well stimulation equipment for downhole hydraulic fracturing and, in particular, to a remote launch system and to a staging valve system with bypass for launching an activation device into a frac tree. This disclosure also relates to methods of staging an activation device from a low pressure in a launching system to a high pressure in a frac tree.

[0004] BACKGROUND

[0005] Methods for completing hydrocarbon wells often involve isolating zones of interest using packers, cement and the like, and pumping fracturing fluids into the wellbore to stimulate one or more production zones of a well. For example, the casing of a cased wellbore may be perforated to allow oil and / or gas to enter the wellbore and fracturing fluid may be pumped into the wellbore through the perforations into the formation. For open, un-cased wellbores, stimulation may be carried out directly in prescribed zones without the need to perforate the production casing. Downhole completion equipment may use downhole tools that are actuated by actuation devices such as balls or darts. The downhole devices may include ball-actuated sleeves or dart-actuated sleeves, which may be arranged in series. The frac sleeves block access to side ports, blocking fluid access to an associated production zone until an appropriate activation device is pumped down from the surface to open the sleeve. The activation device typically lands on a seat in the frac sleeve and frac fluid pressure on the activation device forces the side ports in the frac sleeve to open and provide fluid access to that production zone. Other types of fracing operations and ball- or dart-actuated downhole devices are well known in the art.

[0006] This process of hydraulic fracturing ("fracing") creates hydraulic fractures in rocks, with a goal to increase the output of a well. The hydraulic fracture is formed by pumping a fracturing fluid into the wellbore at a rate sufficient to increase the pressure downhole to a value in excess of the fracture gradient of the formation rock. The fracture fluid can be any number of fluids, ranging from water to gels, foams, nitrogen, carbon dioxide, or air in some cases. The pressure causes the formation to crack, allowing the fracturing fluid to enter and extend the crack further into the formation. To maintain the fractures open after injection stops, propping agents are introduced into the fracturing fluid and pumped into the fractures to extend the breaks and pack them with proppants, or small spheres generally composed of quartz sand grains, ceramic spheres, or aluminum oxide pellets. The propped hydraulic fracture provides a high permeability conduit through which the formation fluids can flow to the well.

[0007] At the surface, hydraulic fracturing equipment for oil and natural gas fields typically includes frac tanks holding fracturing fluids coupled through supply lines to a slurry blender, one or more high-pressure fracturing pumps to pump the fracturing fluid under high pressure to the frac head of the well, and a monitoring unit. Fracturing equipment operates over a range of high pressures and injection rates. Many frac pumps are typically used at any given time to maintain the very high, required flow rates into the frac head and into the well.

[0008] An industry standard prior art fracturing tree ("frac tree") is typically mounted vertically above a wellhead and includes a frac head, sometimes termed a "pump block", which is a large block of steel for injecting frac fluids for pumping through the wellhead and downhole. Since the frac head is mounted above the wellhead, it may be at an elevation of about 14-16 feet (about 5 meters) from the ground. The frac head includes single or multiple fluid inlets which are connected to frac fluid supply lines to allow frac fluids to be combined from a single or from multiple supply lines into the central bore of the frac head. The combined flow of frac fluids is pumped under high pressure downwardly through a bottom outlet of the frac tree and into the central bore of the wellhead. Frac tree components below the frac head and above the bottom outlet of the frac tree generally include a swab valve and one or more master valves. A main axial passageway extends through the frac tree from the central bore of the frac head through the master valves to the bottom outlet. The axial passageway is generally a radial bore to accommodate radial balls or cylindrical darts being launched through the frac tree. A flow back tee, is typically a standard component of a frac tree. The flow back tee accommodates fluids flowing back through the frac tree for diversion through one or more valved side arms. For instance, a ball catch device may be connected to a frac tree side arm for balls being returned from the wellbore through the wellhead.

[0009] To stimulate multiple zones in a single stimulation treatment, a series of packers in a packer arrangement is inserted into the wellbore, each of the packers being located at intervals for isolating one zone from an adjacent zone. An activation device is introduced from the frac tree into the wellbore to selectively engage one of the packers in order to block fluid flow therethrough, permitting creation of an isolated zone uphole from the packer for subsequent treatment or stimulation. Once the isolated zone has been stimulated, a subsequent activation device is dropped to engage a subsequent packer, upstream of the previously engaged packer, for isolation and stimulation thereabove. The process is continued until all the desired zones have been stimulated. In the case of frac balls, the balls may range in diameter from a smallest ball, suitable to engage the most distant packer, to the largest diameter, suitable for engaging the packer located most proximate the surface. Other stimulating methods are known which involve dropping repeater balls of same or similar size.

[0010] U.S. Patent No. 8,636,055 issued Jan. 28, 2014 to Young et al., describes a ball drop system in which the balls are arranged vertically, on above another, with the smallest at the bottom and the largest at the top of a ball cartridge that is mounted above the frac head. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which balls of a ball stack supported by the ball rail are sequentially dropped from the ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail. Depending on the number of balls needed for a system, this system adds excessive height to the overall frac tree, raising safety issues and making it difficult and costly to service and install. As well, when exposed to the high pressures of the frac tree system, and coupled with the extreme freezing temperatures during use, the balls may fail to release when the aperture is opened.

[0011] When operational problems occur, for example malfunctioning valves, activation device failing to deploy, or activation devices becoming stuck and not being pumped downhole, these problems may result in failed well treatment operations, requiring costly and inefficient re-working. At times re-working or re-stimulating of a well formation following an unsuccessful stimulation treatment may not be successful, resulting in a production loss.

[0012] Another technique to introduce frac balls involves an array of remote valves positioned onto a multi-port connection at the wellhead with a single ball positioned behind each valve. Each valve requires a separate manifold fluid pumper line and precise coordination both to ensure the ball is deployed and to ensure each ball is deployed at the right time in the sequence, throughout the stimulation operation. The multi-port arrangement requires multiple high pressure valves and other equipment, increasing the capital costs for the frac operation. The multiplicity of high pressure lines logistically limits the number of balls that can be dropped due to wellhead design and available ports without re-loading. U.S. Patent No. 9,109,422 to Ferguson et al. discloses a system of this nature. The balls are individually pumped directly into the frac head where high turbulence may damage the balls. As well, larger packer balls generally need to be launched from above the frac tree, making the launch more complicated. U.S. Patent Nos. 8,256,514 and 8,561,684 to Winzer, assigned to Applicant, disclose a ball drop system with a vertically stacked manifold of pre-loaded balls oriented in a bore axially aligned above the main axial passageway of the frac head. Each ball is temporarily supported in the bore by a rod. Each rod is sequentially actuated to withdraw from the bore when required to release or launch the next largest ball. The lowest ball (closest to the wellbore of the wellhead) is typically the smallest ball, although same sized balls may be loaded.

[0013] U.S. Patent No. 10,435,978 to Corbeil describes a ball drop system mounted above a wellhead assembly. The balls are loaded in a vertical stack in a manifold, with each ball temporarily supported on a hinged pin for sequential dropping into the bore of the wellhead assembly. The wellhead assembly includes ball launch valves above and below a staging assembly to allow the balls to be sequentially dropped into the wellhead located therebelow, while maintaining the ball injector at atmospheric pressure.

[0014] In most of the above launch systems, if an activation device is damaged or disintegrates upon arrival at the downhole tool, a replacement must be reloaded and launched again. If the launch system is pressurized, as it is for most of the prior art systems, the entire apparatus must be depressurized, removed and reloaded for the replacement activation device. Due to the size, weight and height of these systems, this is a time consuming and costly process, and must be carefully managed to maintain safe control in a hazardous environment and to complete testing and re-pressurization procedures upon reinstallation to the wellhead. An atmospheric launch system addresses some of these issues.

[0015] It has recently become possible to use cylindrical darts instead of a series of sized frac balls to engage and / or activate downhole tools. The cylindrical darts may carry mechanical activation devices to activate the downhole tool, or they may carry sensors to activate the downhole tool. The latter type of cylindrical frac darts are often termed “smart darts”. The use of darts in the fracing industry changes the requirements for the launching systems and methods at the surface. This disclosure is directed to improvements in the launching of activation devices such as balls, darts, plugs and drones to activate downhole tools.

[0016] Fracturing operations involve a large number of trucks, pumps, mixers, containers, hoses or other conduits, and other equipment for a fracturing system. In practice, many trucks and pumps are used to provide the cumulative amounts of fluid for the well at a well site which are moved from well to well. The difficulty of working around the wells with the large number of components also causes safety issues. The number of assembled equipment components raises the complexity of the system and the ability to operate in and around the multiple wells. An area within about 20-30 m of the well is termed a “hot zone”, or “exclusion zone”, and access to the exclusion zone is restricted for safety reasons. Improvements are still needed in the launching of activation devices to simplify the complexity and reliability of the system and to improve overall safety of the fracturing operation.

[0017] Pneumatic launch systems for fracturing operations are described in U.S. Patent No. 11,879,301 to Watkins et al., and in Applicant’s PCT Patent Publication No. WO 2023 / 197072 to Farquharson et al. Pneumatic launching of activation devices have advantages, particularly for activation devices such as smart darts, since the ball or dart can be maintained at atmospheric pressure and in a dry environment during the launch, while limiting exposure of the ball / dart to the corrosive and high pressure environment of the frac fluids during the launch. As well, the pneumatic launch system can improve safety by moving human involvement outside the exclusion zone.

[0018] As noted above, the frac head of the frac tree receives frac fluids under high pressure from a single supply line, or from a plurality of supply lines. The frac head presents a harsh environment due to the high pressure, high velocity, high density and erosive nature of the frac fluid stream(s) being pumped from the supply line(s). Because of the density, velocity and pressure of the frac fluid stream(s) entering the frac head, activation devices may experience issues in entering into the frac fluid stream, and may end up sitting or idling on top of the frac fluid stream, without launching through the frac head and into the frac tree components and wellhead located therebelow.

[0019] Staging valve systems to assist with launching an activation device through a frac head are described in Applicant’s PCT Patent Publication No. WO 2023 / 197072, and in U.S. Patent No. 11,280,151 to Cherewyk et al. The patents disclose a pressure isolation passageway or staging bore formed between upper and lower isolation valves. Frac fluid pressure and / or use of a stand-alone pump may be used to assist in launching the activation device from the staging valve system into the frac head. Stand-alone pumps used in the industry for staging the activation device are generally only capable of generating about a 0.100 m3 / min fluid flow rate. In order for activation devices to enter into the frac stream merging in the frac head, operators typically slow the rate of the frac fluid pumping from the mixing and pumping equipment in order to pump the activation device into the frac stream. This slowing of the frac fluid stream may have adverse effects to the retention of the solid proppant (sand) in the frac fluid stream at the surface, may reduce proppant migration in the fractures, may increase the pumping time, and may slow the overall fracturing process. Applicant’s previous U.S. Patent Nos. 10,161,218 and 10,731,436 to Allen et al. disclose a ball injector connected below the frac head of the frac tree, making it possible to sequentially inject frac balls from a ball cartridge into the main axial passageway of the frac tree. Valve members in a ball launch passageway enable the ball to be passed from atmospheric conditions in the ball cartridge to high pressure conditions in the main axial passageway of the frac tree, without passing through the harsh environment of the frac head.

[0020] Despite the prior art efforts, launching an activation device through the harsh environment of the frac head remains problematic.

[0021] SUMMARY

[0022] This disclosure provides a staging valve system for staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under the high pressure through one or more supply lines. The staging valve system includes: a first isolation valve operatively connected to the launching system; a second isolation valve operatively connected to the frac head of the frac tree; a pressure isolation passageway between the first isolation valve and the second isolation valve; the first isolation valve, the second isolation valve and the pressure isolation passageway being axially aligned one with another and with an axial passageway extending through the frac head and into the frac tree to permit passage of the activation device from the low pressure in the launching system to the high pressure in the frac tree; a frac fluid bypass line fluidly connecting at least one of the one or more supply lines to the pressure isolation passageway; a bypass valve in the connected supply line, the bypass valve permitting frac fluid flow to the frac head in an open position, and closing the connected supply line and diverting flow of the frac fluid from the closed supply line into the frac fluid bypass line in a closed position; and a bypass isolation valve in the frac fluid bypass line between the bypass valve and the pressure isolation passageway, the bypass isolation valve preventing frac fluid flow in the frac fluid bypass line when in a closed position, and permitting flow of the diverted frac fluid from the frac fluid bypass line into the pressure isolation passageway when in an open position to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the second isolation valve member and the frac head, and into frac tree components below the frac head.

[0023] The disclosure also extends to a method of staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under high pressure from a single supply line or from a plurality of supply lines. The method includes: a) launching the activation device from the launching system into a pressure isolation passageway located between first and second isolation valves of a staging valve system connected above the frac head while isolating the pressure isolation passageway from the high pressure in the frac tree with the second isolation valve in a closed position, and then isolating the launching system and pressure isolation passageway with the first isolation in a closed position; and b) closing the single supply line or one or more of the plurality of supply lines and diverting the frac fluid from the closed single supply line or from each of the one or more closed supply lines through a frac fluid bypass line and into the pressure isolation passageway to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the frac head, and into frac tree components below the frac head.

[0024] In some embodiments, step b) of the above method changes a trajectory of the frac fluid diverted from the closed single supply line or from each of the one or more closed supply lines to a trajectory behind the activation device to push the activation device with the diverted frac fluid generally axially along the pressure isolation passageway and through a central bore of the frac head into the frac tree components below the frac head.

[0025] In some embodiments, step b) of the above method includes opening a bypass isolation valve in the frac fluid bypass line, opening the second isolation valve, and closing a bypass valve in the single supply line or in the one or more of the plurality of supply lines to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the frac head, and into the frac tree components below the frac tree.

[0026] The disclosure also extends to a method of staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under high pressure through one or more supply lines. The method includes: a) providing a staging valve system operatively connected between the launching system and the frac head of the frac tree, the staging valve system including a first isolation valve, a second isolation valve, and a pressure isolation passageway between the first isolation valve and the second isolation valve, the first isolation valve, the second isolation valve and the pressure isolation passageway being axially aligned one with another and with an axial passageway extending through the frac head and into the frac tree to permit passage of the activation device from the low pressure in the launching system to the high pressure in the frac tree; b) providing a frac fluid bypass line fluidly connecting at least one of the one or more supply lines to the pressure isolation passageway; c) providing a bypass valve in the connected supply line, and a bypass isolation valve in the frac fluid bypass line between the bypass valve member and the pressure isolation passageway; d) with the second isolation valve and the bypass isolation valve in closed positions, opening the first isolation valve to launch the activation device through the first isolation valve into the pressure isolation passageway and closing the first isolation valve; e) opening the bypass isolation valve and the second isolation valve and closing the bypass valve to close the connected supply line and to divert the frac fluid from the closed supply line into the frac fluid bypass line and into the pressure isolation chamber to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the second isolation valve and the frac head, and into the frac tree; and f) opening the bypass valve and closing the second isolation valve and the bypass isolation valve to resume frac fluid flow from the previously closed supply line into the frac head and into the frac tree components below the frac head.

[0027] In some embodiments, the above method further includes g) bleeding off pressure from the pressure isolation passageway and repeating steps d) - f) for launching each subsequent one of a plurality of activation devices.

[0028] BRIEF DESCRIPTION ON THE DRAWINGS

[0029] FIG. 1A is a schematic, side perspective view of a launching system for launching an activation device, such as a cylindrical dart, from a ground level loading station remote from a frac tree, and with a pneumatic line extending between the loading station and a staging valve system, which is in turn connected to the frac head of a frac tree. The pneumatic line includes a vented adapter between the loading station and the staging valve system to discharge the activation device from a carrier for delivery to the staging valve system. The staging valve system includes bypass components for launching the activation device through the frac head into frac tree components below the frac head. FIG. IB is a partially cut-away view of a section of the pneumatic line of FIG. 1, showing a carrier and a cylindrical dart being pneumatically conveyed in the pneumatic line.

[0030] FIG. 1C is a partially cut-away view of a section of the pneumatic line of FIG. 1, showing connection details between sections of the pneumatic line.

[0031] FIG. ID is a side perspective view of an air source connected to a manifold air distribution system for selectively supplying air or vacuum to one of a plurality of loading stations, each of which is connected to a pneumatic line extending between the loading station and a staging valve system, which is in turn connected to the frac head of a frac tree.

[0032] FIG. IE is a top view of the manifold air distribution system of FIG. ID.

[0033] FIGS. 2A, 2B and 2C are perspective, end and sectional views respectively of an embodiment of a cylindrical carrier for pneumatic conveying an activation device.

[0034] FIG. 3A is a side sectional view of the vented adapter at the high point of the pneumatic line, showing a stop to arrest the carrier and discharge the activation device, and also showing a transition of the pneumatic line from a diameter to accommodate the carrier to a reduced diameter to accommodate the activation device.

[0035] FIGS. 3B and 3C are exploded perspective views of the vented adapter showing the groove and slot details at the flanged connection for alignment of the flange faces.

[0036] FIGS. 4A, 4B, 4C are perspective, front and side views respectively, and FIGS. 4D, 4E and front and side schematic views respectively, of an embodiment of the staging valve with bypass system connected to the frac head of a frac tree. The frac tree is of the type in which four frac fluid supply lines are connected to the frac head. The staging valve with bypass system includes a pressure isolation passageway between upper and lower isolation valves, a single bypass frac fluid line connected between one of the four supply lines at one end and the pressure isolation passageway at the other end, a bypass valve in the connected supply line, a bypass isolation valve in the frac fluid bypass line between the bypass valve and the pressure isolation passageway, and a bleed off valve system connected to the pressure isolation passageway.

[0037] FIGS. 5A, 5B, 5C, 5D and 5E and are perspective, front, and side views, and front and side schematic views respectively, of another embodiment of the staging valve system connected to the frac head, in which, similarly to FIG. 4A, four frac fluid supply lines are connected to the frac head. The staging valve with bypass system includes the pressure isolation passageway and upper and lower isolation valves similarly to FIG. 4A. However, two frac fluid bypass lines are provided, each one of the bypass lines extending between one of the supply lines and the pressure isolation passageway. A bypass valve and a bypass isolation valve are associated with each of the bypass lines. A bleed off system is connected to the pressure isolation passageway, similarly to FIG. 4A.

[0038] FIGS. 6A, 6B and 6C are perspective, front and side views respectively of another embodiment of the staging valve system connected to a frac head of a frac tree. The frac tree is of the type in which a single frac fluid supply line is connected to the frac head. The staging valve with bypass system includes a pressure isolation passageway between upper and lower isolation valves, a single bypass frac fluid line connected between the single frac fluid supply line at one end and the pressure isolation passageway at the other end, a bypass valve in the supply line, a bypass isolation valve in the frac fluid bypass line between the bypass valve and the pressure isolation passageway, and a bleed off valve system connected to the pressure isolation passageway.

[0039] FIGS. 7A-7I are schematic views similar to FIG. 4D, showing the sequence of opening and closing the valves of the staging valve with bypass system, the direction of fluid flow, and the position of the activation device during a sequence to launch an activation device into the pressure isolation passageway, to isolate the activation device within the pressure isolation passageway, to close the connected frac fluid supply line and to divert the frac fluid from the closed supply line through the bypass line, into the pressure isolation passageway, and to launch the activation device with the diverted frac fluid through the frac head and into the frac tree components below the frac head. Closed valves are depicted by (X), while open valves are depicted with the direction of fluid flow.

[0040] DETAILED DESCRIPTION

[0041] Terms and Definitions

[0042] Certain terms or phrases used herein and in the claims have meanings as set out hereinbelow.

[0043] Although described in the embodiments as having a cylindrical configuration, the term “activation device” is used throughout this disclosure and in the claims to be generic to other configurations of activation devices configured to engage and / or activate a downhole tool, for example by shifting a sliding sleeve as described above. The term “activation device” specifically includes spherical and cylindrical configurations, for example, darts, balls, plugs, and drones, semi-ellipsoidal configurations, and other configurations capable of sealing or restricting fluids by engaging a seat, or otherwise activating an activation or de-activation mechanism in a downhole tool. “Axial” and “longitudinal” are used to indicate a direction or center axis along a line substantially parallel with, or along, a lengthwise direction, for example of an axial passageway through a launch housing, a staging valve system, a frac head, a frac tree, a wellbore, or other feature at the relevant point or portion of the feature under discussion.

[0044] “Radial” means a direction or including a directional component substantially along a line that intersects the center axis of the feature under discussion, for example which lies in a plane perpendicular to the center axis.

[0045] “Circumferential” means a substantially arcuate or circular path described by rotation of a tangential vector about a center axis of the feature under discussion, for example along the outer surface of a cylindrical carrier or activation device.

[0046] As used herein, movement or location “forwards” or “downhole” (and related terms) means axial movement or relative axial location toward a frac head, frac tree, wellhead or downhole tool, away from the earth's surface. Conversely, “rearwards,” means movement or relative location axially away from the downhole, including upwardly though the wellhead, frac tree, frac head, staging valve system, launch housing and returning to the earth’s surface.

[0047] “Above” or “below” as used herein denote a location generally vertically above or below another feature under discussion, for example a frac head or a frac tree, without implying a strictly vertical position, for example including a vertically raised position relative to another feature, and without excluding other intervening connected features such as valves, adapters etc.

[0048] “Connected”, “connecting” and “connection” as well as “operatively connected” and “fluidly connected” are used herein to include direct and indirect connections between features under discussion, without excluding other intervening connected features such as valve, adapters or other components. Connections within, to and between wellhead, frac tree and staging valve with bypass system components are understood to be pressure connections with seals to withstand industry standard pressure ratings.

[0049] “Frac iron” as used herein refers to frac surface piping, valves, manifolds and connections used to deliver a frac treatment fluid to the wellbore from the mixing and pumping equipment. Frac iron components are rated for high pressure delivery of frac treatment fluids, for example about 15,000 psi (103.4 MPa).

[0050] “Frac fluid supply line” is used herein to refer to frac iron surface piping connecting to the frac head to deliver frac fluid treatment under high pressure to the frac head of the frac tree.

[0051] “Frac treatment fluid” and “frac fluid” are used herein to refer to frac treatment fluid pumped through frac iron under high pressure from mixing and pumping equipment. The frac treatment fluid is typically composed primarily of water and proppants (typically sand), with additional chemicals added, such as friction reducers, surfactants, etc. i) Pneumatic Launching System

[0052] Exemplary embodiments of a pneumatic launching system, a staging valve with bypass system, and methods of launching and staging an activation device are shown in FIGS. 1-7, and are described in detail hereinbelow. The details of Applicant’s pneumatic launching system described in PCT Patent Publication No. WO 2023 / 197072 are incorporated herein by reference.

[0053] FIGS. 1 - 3 show embodiments of a pneumatic launch system 40, and 540, while FIGS. 4-7 show multiple embodiments of a staging valve with bypass system 42, 42' and 42" for launching and staging an activation device into a frac tree 10. One embodiment of an activation device is shown in FIG. IB as a cylindrical dart 41. While the launch systems 40, 540 are shown as a pneumatic launch systems, and in particular for launching one or more cylindrical darts 41 as activation devices, it should be understood that the disclosure extends broadly to other launch systems for launching activation devices, including for example balls, darts, plugs or drones, into a frac tree, or into other surface equipment to activate downhole tools.

[0054] With reference to FIG. 1A, the pneumatic launch system 40 is shown connected to an industry standard fracturing tree ("frac tree") 10. The components of the frac tree 10 include a bottom connector 12 for mounting to a wellhead (not shown but located below the frac tree 10). The frac tree 10 includes a frac head 20, sometimes referred to in the industry as a "pump block", which is a large block of steel for injecting frac fluids into the frac tree 10 under high pressure. As used herein and in the claims, the term "frac head" is understood to comprise the block of a frac tree 10 into which frac fluids are pumped under high pressure from one or more frac fluid supply lines 29 through side inlets 28. The frac head component 20 of the frac tree 10 is mounted above the wellhead, so may extend generally vertically upwardly to an elevation of about 14-16 feet (about 5 meters) from the generally horizontal ground at the earth’s surface. The connections between components of the frac tree 10 are shown as studded up / studded down connections or flange connections, however, other known connections may be used. Each of the frac fluid supply lines 29 (labeled 29a-29d in FIG. 1 A) is attached to one of the side inlets 28 of the frac head 20. The side inlets 28 allow the frac treatment fluids to be pumped under high pressure from pumping and mixing equipment (not shown) through frac iron into the central bore of the frac head 20. The combined flow of frac fluids is pumped downwardly under pressure, through the frac tree components into the central bore (wellbore) of the wellhead.

[0055] In FIG. 1A, the frac tree 10 includes a swab valve 30a and upper and lower master valves 30b, 30c positioned below the frac head 20 connection and above the bottom connector 12 of the frac tree 10. The valves 30a, 30b, 30c are typically industry standard gate valves which may be manually controlled or remotely controlled such as hydraulically. An axial passageway 32 extends through the frac tree 10 from the central bore (not shown) of the frac head 20 through the valves 30a, 30b, 30c. The axial passageway 32 is generally a radial passageway. FIG. 1A also shows a flow back tee 34, which is usually also a standard component of a frac tree 10. The flow back tee 34 accommodates fluids flowing back through the frac tree 10 for diversion through the one or more valved side arms 36. The axial passageway 32 of the frac tree 10 also extends through the flow back tee 34, if present. In some embodiments, a ball catcher (or dart catcher) may be included as a component of the frac tree or of the staging valve with bypass system 42. Other components, such as valves or adapters may be present in a frac tree 10, as is known in the industry.

[0056] The launch system 40 of FIG. 1A is connected to a staging valve system with bypass components (i.e., staging valve with bypass system), shown generally at 42, which in turn is connected to the frac head 20 of the frac tree 10. The connections between components of the staging valve system 42, the frac head 20 and the frac tree 10 are shown to be industry standard flange connections or studded up / studded down connections, with pressure rated seals. However, other industry standard connections with seals rated for the high pressure within the frac tree 10 may be used, for example welded, threaded or hub connections, or hammer unions.

[0057] The launch system 40 includes a loading station 44 and an air source 46, both of which are located remotely from the frac tree 10, i.e., outside the exclusion zone of a well pad on which the frac tree 10 is located. This exclusion zone distance may be, for example, about 20-30 m from the frac tree 10. The loading station 44, the air source 46, and carriers 80 for pneumatic conveyance of the cylindrical dart activation device 41 are more fully described in Applicant’s PCT Patent Publication No. WO 2023 / 197072, specifically incorporated herein by reference.

[0058] A pneumatic line 56 is connected to, and extends between, the loading station 44 and the staging valve with bypass system 42. In some embodiments, the pneumatic line connections vary, for example with the type, weight, and angle of connection of the pneumatic line 56, but exemplary pneumatic line connections include industry standard flange, threaded, hose clamp, wing union, hammer union, and welded connections, or camlock fittings.

[0059] In some embodiments, the pneumatic line or sections of the pneumatic line 56 are tubular, and flexible, such as in the form of a flexible hose or piping. In some embodiments, a flexible hose is provided in a single length, or in multiple joined lengths (sections), and with a smooth curvature to accommodate a ground connection at the loading station 44 and a raised connection to the staging valve with bypass system 42 above the frac tree 10. In some embodiments, the flexible hose has one or more transparent portions to provide visual monitoring of the pneumatic conveyance. In some embodiments, the flexible hose is spiral wound flexible hose with a generally smooth inner wall for sealed pneumatic conveyance. In other embodiments, the pneumatic line 56 may include one or more sections of hard piping such as steel piping joined with flexible piping, and / or sections of aluminum reinforced piping joined with flexible piping. In some embodiments the pneumatic line may include one or more straight sections joined with one or more flexible and / or curved sections, for example spiral wound hose sections joined to curved steel or aluminum sections. In some embodiments the flexible piping can include carbon fiber piping or corrugated piping. Exemplary materials for the flexible hose include PVC, polyurethane and other flexible plastics. It should be understood that some air leakage within the pneumatic line and connections is permitted, such that pneumatic sealing need not be air tight sealing.

[0060] In the embodiment of FIG. 1A, the pneumatic line 56 includes a vented adapter 200 in the pneumatic line 56 between the end connections. The pneumatic line 56 is shown to include two linear sections of spiral wound flex hose 202 and three curved steel pipe sections 204. Hammer union connections 206 are shown between spiral wound flex hose sections 202 and curved steel sections 204, while flanged connections 207 are shown at the vented adapter 200, between joined curved steel sections 204, and between the curved steel pipe section 204 and the top connector 209 of the staging valve with bypass system 42 (for example, the top flange 209 of upper isolation valve 62). Hammer union connections 206 are also shown for connections of the pneumatic line 56 to the loading station 44 and to the vented adapter 200. Groove and slot connectors 210, as shown in FIG. 3B, 3C, are included in the flanged connection 207 of the vented adapter 200 for ease of alignment and connecting. Plastic inserts 212, shown in FIG. 1C, are included at the connections 206 to improve low friction pneumatic conveyance at the connections 206, and to accommodate the difference in the ID between the flexible piping section 202 and the hammer union 206.

[0061] In FIG. 1A, the two joined curved steel pipe sections 204 are shown to extend above the height of the staging valve with bypass system 42, forming a raised section R of the pneumatic line 56, with an arc of curvature to accommodate the OD and length of the carrier 80 in the section before the vented adapter 200, and to accommodate the OD and length of the activation device 41 beyond the vented adapter 200. The vented adapter 200 is located in the pneumatic line 56, generally in this raised section R of the pneumatic line 56. The vented adapter 200 is shown in greater detail in FIGS. 3A, 3B and 3C. The vented adapter 200 includes a reduced diameter stop 90, which functions to discharge the activation device 41 from the carrier 80 upon striking the stop 90. The discharged activation device 41 has momentum to continue travel through the remaining length of the pneumatic line 56 for gravity delivery with a generally vertical orientation into the staging valve system 42. The passageway 208 through the vented adapter 200 is shaped and sized to accommodate a carrier 80 and the activation device 41. As shown in FIG. 3A, the diameter of the passageway 208 is reduced after the flanged connection 207, as the pipe section 204 extending to the staged valve with bypass system 42 need only accommodate the activation device 41, without the carrier 80. This pipe section 204 may provide additional rigidity to accommodate unloading of the activation device at the vented adapter 200. The vented adapter 200 includes vents 200a for air flow and to release any fluid from the pneumatic line 56. In some embodiments, screens 200b over the vents 200a prevent debris entering the pneumatic line 56, and prevent a small activation device from exiting the pneumatic line 56.

[0062] In some embodiments, pneumatically conveying the activation device 41 through the pneumatic line 56, to the staging valve with bypass system 42, includes using a carrier 80 within the pneumatic line 56 to carry the activation device 41, or to push the activation device. The carrier 80 may be formed from a light weight material for ease of conveyance, for example from metals such as aluminum, or from hard plastics such as polycarbonate or Teflon™. As shown in one embodiment of a carrier in FIGS. 2A, 2B and 2C, the carrier 80 includes a generally cylindrical body 82 with at least one closed end 84. In some embodiments the carrier 80 is generally hollow for ease of conveyance, and for carrying the activation device 41. The carrier includes one or more seals 86 carried on an outer surface 80a of the carrier 80 to support the carrier 80 within the pneumatic line 56. The seals 86 may be one or more circumferential seals 86, for example two or more spaced circumferential seals of low friction materials with high strength and high wear, for example hard plastics such as hydrogenated nitrile (HNBR), polytetrafluoroethylene (PTFE) seals such as Teflon™, high density polyethylene (HDPE), ultra high molecular weight polyethylene UHMW polyethylene, polyurethane, polyacrylate rubber (ACM), highly saturated nitrile (HSN) and nitrile rubber (NBR), fibrous seals such as leather, reinforced fiber seals, or composite seals of both plastic and fibrous materials. The seals 86 and body 82 are sized for close contact with the inner wall 56b of the pneumatic line 56 such that air pressure from the air source 46 imparted on the closed end 84 of the carrier 80 pneumatically conveys the carrier 80 and the activation device 41 through the pneumatic line 56. In some embodiments, additional low friction seals or guides may extend longitudinally, for example as longitudinal plastic strips or runners, or metal blades, radially spaced around the outer surface. Exemplary low friction materials include polyurethane, polytetrafluoroethylene (PTFE), ultra high molecular weight polyethylene (UHMW polyethylene), and high density polyethylene (HDPE). In other embodiments, the outer surface 80a may include other support features such as low friction spacers, bars or wheels radially spaced around the outer surface 80a.

[0063] In the embodiment of FIG. 1A, the closed end 84 of the carrier 80 is rearward facing toward the air source 46, and the opposing end of the carrier 80 is an open end 88, such that the activation device 41 is discharged through the open end 88 when the carrier strikes the stop 90 in the vented adapter 200, for delivery in a hands free manner (i.e., without human hands contacting the carrier or the activation device 41). This embodiment is well adapted for pneumatic conveyance of a cylindrical smart dart, but may also be used for other shaped activation devices.

[0064] In some embodiments both ends of the carrier are closed ends such that the activation device, whether cylindrical or of a different shape such as a spherical frac ball, is pushed ahead of the carrier during pneumatic conveyance.

[0065] In some embodiments, the carrier is adapted as a service tool carrying brushes at one or both ends of the carrier to run through the pneumatic line 56 to clean out potential debris from the hose and pipe sections 202, 204.

[0066] In FIGS. 2A, 2B and 2C, the carrier 80 is formed from a light weight material such as aluminum, polycarbonate or Teflon™, the open front end 88 of the carrier body 82 is tapered, and the closed end 84 is formed by an end plate 84a bolted to the carrier body 82. The circumferential seals 86 are spaced apart on the outer surface 80a of the carrier 80, with one of the circumferential seals 86 providing an air block seal, formed for example from a reinforced fibrous material or multiple sheets of the above mentioned low friction materials. For retaining a spherical ball as an activation device, the open front end 88 includes an inwardly extending lip 87. The lip 87 is generally not included for cylindrical activation devices.

[0067] The air source 46 provides a bidirectional air supply to the pneumatic line 56. The air supply 46 is shown to be located rearwardly of the loading station 44 to provide air pressure against the carrier 80, once the carrier 80 and activation device 41 are loaded into the pneumatic line 56. In some embodiments, the air source 46 is a regenerative air blower with an air line and a vacuum line joined for connection to the loading station 44, and with controls to switch between imparting air pressure in the pneumatic line 56 and imparting vacuum pressure in the pneumatic line 56. In some embodiments, the air source 46 includes a valve-controlled bleed off port and valve controlled inlet port as part of the controls for the air source 46. Once the activation device 41 is discharged at the vented adapter 200, the air line control is closed, and the vacuum line control is opened to return the empty carrier 80 to the loading station 44 by imparting vacuum pressure to the carrier 80 in the pneumatic line 56. To launch each subsequent activation device 41, and to return the carrier to the loading station 44, the pneumatic conveyance and vacuum return steps are repeated. In some embodiments, the air source 46 may include multiple regenerative air blowers, for example to provide back up in the event of failure of a blower.

[0068] To load the activation device 41 at the loading station 44, the loading station 44 includes a tubular loading housing 110 sized to accommodate the carrier 80 and the activation device 41. The loading housing 110 is connected to the air source 46 at one end, and to the pneumatic line 56 at the other end. A sealed loading port 120 is formed in the upper surface of the loading housing 110 for loading of the carrier 80 and the activation device 41. An arcuate loading port cover 122 provides open and closed positions of the port 120. The cover 122 may be hinged along a side or end for opening and closing, and the cover 122 may carry perimeter seals on its underside for sealing the port 120 in the closed position.

[0069] While the loading station 44 is shown schematically as being ground supported, it will be understood that in some embodiments the loading station 44 may be elevated to decrease the rise or height of raised section R of the pneumatic line 56 and thus the work to convey the carrier 80 and the activation device 41 from the loading station 44 into the frac tree 10. In some embodiments the loading station 44 may be adapted to accept a magazine loaded with a plurality of activation devices for sequential loading into the carrier 80. In some embodiments, the loading station 44 may be adapted to open the door 122 of the loading station 44 on return of the carrier 80 to the loading station 44. In some embodiments, the loading station 44 and the air source 46 may be housed in a climate controlled environment or module, for example in a trailer or shipping container equipped for human and / or computer operations and monitoring. In some embodiments the air source 46 may be located elsewhere than rearwardly of the loading station 44, for example proximate the staging valve with bypass system 42. The air source 46 may be adapted to use blowing air for the conveying path, i.e., to convey the carrier 80 and activation device 41 along the pneumatic line 56 for launching into the frac tree 10, and then vacuum for the return path, or the air source 46 may be adapted to use vacuum for the conveying path and blowing air for the return path.

[0070] In the above described embodiments, the activation device 41 is shown as a cylindrical dart. In some embodiments, the activation device may be spherical, such as a frac ball, and the launch passageway has a radial dimension to accommodate the diameter of the frac ball. In some embodiments, the activation device may be a plug or a drone.

[0071] In some embodiments, as shown in FIGS. ID and IE, the pneumatic launch system 540 is adapted to enable launching of an activation device to a selective frac tree of a plurality of frac trees. This provides extended reach to multiple wellbores across a lease site or to remote wellbores located at separate well sites. FIGS. ID and IE illustrate an air source 546 supplying air to four loading stations 544A-544D through a manifold air distribution system 545. Each of the loading stations 544A-544D is connected to a pneumatic line, labeled as 556A-556D. Although not shown in the figures, each of the pneumatic lines 556A-556D is connected to a staging valve system and the frac head of a frac well, similarly to that described for pneumatic line 56 in FIG. 1A. The manifold air distribution system 545 of FIG. ID, IE shows four loading stations and pneumatic lines, it will be understood that the manifold system may be adapted for additional or fewer loading stations and pneumatic lines for pneumatically launching an activation device to a selective frac tree from a plurality of frac trees, or for pneumatically launching multiple activation devices, either simultaneously, or sequentially, each one of the activation devices being launched to a selective one of a plurality of frac trees.

[0072] The air source 546 is similar to that described in FIG. 1A, providing a bidirectional air supply to each pneumatic line 556A-556D. The air supply 546 may be located rearwardly of the loading stations 544A-544D to provide air pressure against a carrier, once the carrier and activation device are loaded into the selective loading station 544A-544D. The air source 546 is shown to include a regenerative air blower with an air line 500 and a vacuum line 502 joined at joined section 501 of the air / vacuum lines 500, 502. The lines 500, 502, include valve controls 504, 506 to switch between imparting air pressure in the manifold system 545 and imparting vacuum pressure in the manifold system 545. A valve-controlled bleed off port 522 and valve controlled inlet port 520 are included as part of the controls for the air source 546.

[0073] The manifold air distribution system 545 is operative to distribute air from the air source 546 to a selective one of the pneumatic lines 556A-556D through a valved manifold line 530. The manifold line 530 is connected to the joined section 501 of the air / vacuum lines 500, 502 by a T-connector 542. The manifold line 530 includes spaced line sections 541, spaced T- connectors 543 and closed end elbows 547. The manifold line 530 distributes air (or vacuum) to a selective one of the loading stations 544A-544D though one of a plurality of the feeder lines 548A-548D. Each feeder line 548A-548D connects to a respective one of the loading station 544A-544D through a line control valve 549A-549D and a nipple connector 550A-550D.

[0074] In the neutral position of the manifold air distribution system 545, valves 520 and 522 are in open positions, and the other valves are closed. To launch an activation device to a selective frac tree, the staging valve system for that selective frac tree is prepared to receive the launch, as described more fully below for the staging valve system. The carrier and the activation device are loaded in a selective one of the loading stations 544A-544D. The operator opens the air control valve 504 in the air line 500, and the selective line control valve, one of 549A-549D, for that loading station 544A-544D. The other valves and controls for the other loading stations, and the vacuum line 502 are generally in a closed position. This launches the activation device from the selective loading station, through the selective pneumatic line to the selective staging valve system of the selective frac tree. Once the activation device is discharged at the selective staging valve system of the selective frac well, the vacuum line control valve 506 in vacuum line 502 and bleed off valve 522 are opened, the air line control valve 504 and inlet port valve 520 are closed, and the empty carrier is returned to the selective loading station by imparting vacuum pressure to the carrier in the selective pneumatic line. Once the carrier is returned, the selective line control valve 549A-549D is closed and the system 545 is returned to the neutral position, with valves 520, 522 in open positions and other valves closed. To launch each subsequent activation device, and to return the carrier to a selective loading station, the pneumatic conveyance and vacuum return steps are repeated.

[0075] In some embodiments, the manifold air distribution system includes components of the manifold line and connections that make smooth transitions, minimizing right angle bends, to increase the efficiency of the airflow within the manifold system. In some embodiments, the manifold air distribution system may include individual line control valves for each loading station as described above, or a selector valve can be used to distribute air (or vacuum) to multiple feeder lines and loading stations, and thus to multiple selective frac trees, for simultaneous or sequential pneumatic launching of activation devices to multiple wells, ii) Staging Valve with Bypass System

[0076] Multiple embodiments of a staging valve system with bypass are shown in the FIGS. 1A and 4-7. While shown with a pneumatic launching system in FIG. 1 A, other launching systems may be used with the staging valve with bypass system of this disclosure. The staging valve system with bypass (shown generally at 42 in FIG. 4A) includes a first isolation valve 62 (i.e., an upper isolation valve), a pressure isolation housing 64 and a second isolation valve 66 (i.e., a lower isolation valve). A generally radial valve passageway 68 extends through the valve members 62, 66 and the pressure isolation housing 64, sized to allow an activation device 41 to pass therethrough, into the frac head 20 of the frac tree 10, when the valves 62, 66 are in open positions. The valve passageway 68 is axially aligned with the axial passageway 32 extending through the frac tree 10. In some embodiments, the valve members 62, 66 are hydraulically actuated gate valves, but other industry standard valves may be used. In some embodiments, additional valve components may be included, for example an isolation valve may be replaced by two isolation valves to create a catch valve to assist in pinpointing or monitoring the activation device into the frac stream.

[0077] The staging valve with bypass system 42 is shown to include a bleed off valve 70 fluidly connected to the pressure isolation housing 64. In FIG. 4A, the bleed off valve 70 is positioned in a side arm 98 connected to the pressure isolation housing 64. A pressure isolation passageway 72, best seen in FIG. 7A, extends through the pressure isolation housing 64. The passageway 72 is shown to be generally cross-shaped, with a side passageway 74 fluidly connected to the side arm 98 and the bleed off valve 70 for bleeding off pressure and excess fluid from the pressure isolation passageway 72 through a dump line 99 into a dump tank 75. This bleed off step is generally conducted before the initial launch of an activation device, and then after each sequential launch of an activation device. To prevent damage to the activation device, a column of residual fluid may remain in the pressure isolation passageway 72 at the end of each bleed off step, such that during launch, the activation device 41 lands in the column of fluid in the pressure isolation passageway 72, rather than striking a closed valve member of the lower isolation valve 66. In some embodiments, the bleed off valve 70 is a hydraulically actuated plug valve, or another industry standard valve.

[0078] In FIGS. 4A-4E, and in the valve sequence of FIGS. 7A-7I, the staging valve system with bypass 42 is connected to the frac head 20 of a frac tree 10. The frac head 20 is shown with four frac fluid supply lines 29a, 29b, 29c and 29d connected to the frac head 20 to provide frac fluid under high pressure to the bore of the frac head. A single frac fluid bypass line 100 has a first end 100a operatively connected to one of the supply lines 29a and a second end 100b operatively connected to the pressure isolation housing 64 to fluidly connect to the pressure isolation passageway 72. A bypass valve 102 is provided in the connected supply line 29a (i.e., in the supply line adapted with a connected frac fluid by pass line). The bypass valve 102 is shown to be positioned between a T-connector 103 in the supply line 29a and the side inlet 28 of the frac head 20. In this manner, the bypass valve 102 permits frac fluid flow from the connected supply line 29a into the frac head 20 in an open position, but closes the connected supply line 29a to prevent frac fluid flow into the frac head from the supply line 29a in the closed position. A bypass isolation valve 104 is provided in the frac fluid bypass line 100 between the bypass valve 102 and the pressure isolation passageway 72. In FIG. 4A, the bypass isolation valve 104 is positioned in a side arm 106 connected to the pressure isolation housing 64. The side arm 106 is connected through an angle connector 108 to a vertical pipe section 111, which in turn is connected to the T-connector 103 and to the connected supply line 29a. Thus, the frac fluid bypass line 100 includes between its ends 100a, 100b, the T-connector 103, the vertical pipe section 111, the side arm 106, and the bypass isolation valve 104.

[0079] The bypass isolation valve 104, in a closed position, prevents flow of frac fluid from the supply line 29a. When the bypass isolation valve 104 and the lower isolation valve 66 are both in open positions, frac fluid from the connected supply line 29a flows in the bypass line 100, into the pressure isolation passageway 72 and into the frac head 20. When the bypass valve 102 is closed, the connected supply line 29a is closed, preventing frac fluid from flowing in the connected and closed supply line 29a. When the bypass isolation valve 104 is then opened, the full volume of the frac fluid flow is diverted from the connected and closed supply line 29a into the frac fluid bypass line 100, through the pressure isolation passageway, through the frac head 20 and into the frac tree components below the frac head 20 (i.e., the swab valve 30a in FIG. 4A). In the Figures, the bypass valve 102 and the bypass isolation valve 104 are shown as a hydraulically actuated plug valves, however, other industry standard valves might be used.

[0080] The valves 62, 66, 70, 102 and 104 included in the staging valve with bypass system 42 may be hydraulically actuated from a remote hydraulic source. Each valve is connected to a hydraulic accumulator and a control panel (not shown). For example, a mechanical handle on a control panel can be turned from open / neutral / closed positions by an electric actuator during the staging operation.

[0081] The above-described embodiments show industry standard gate valves for isolation valves 62, 66 and industry standard rotating trunnion plug valves for valves 102, 104 and 70, however, the invention is not limited to using these particular valves. In some embodiments, the speed of operation of industry standard gate valves can slow operation of the staging valve with bypass system (ex. void space in the valve, sand ingress and travel time between fully opened / closed positions). Rotating trunnion plug valves provide faster travel between fully open / closed positions, but generally require high torque loads at the stem of the plug, and complete opening and closing operations under the high differential pressure (i.e., the atmospheric pressure on the launch side, and frac fluid pressure in the frac head) can be an issue. In some embodiments using serviceless, low grease or greaseless gate valves may be advantageous for the valves 62, 66, 102, 104 and 70. The lower grease valves include additional sealing elements between the gate and the seats of the valve, limiting sand intrusion into the valve body, limiting grease stored in the valve, and decreasing void space in the valve. These valves are less affected by operational speed as the void space is not as affected by sand ingress. In some embodiments, one or more equalizing lines (not shown) may be added, for example across bypass isolation valve 104 where the pressure differential ranges from atmospheric to frac pressure. The equalizing line(s) can be used to protect a plug valve by assisting in pressure equalizing across the valve.

[0082] FIG. 4D shows valve position sensors V associated with each of the valves 62, 66, 70, 102 and 104 of the staging system 42 (square symbol used to schematically indicate a valve position sensor). The valve position is sensed by the travel of the balanced stem in the gate valves (62, 66) or by the stem rotational position in the rotating plug valves (102, 104, 70).

[0083] One or more components of the staging valve with bypass system 42 may include position sensors to detect the position and movement of the activation device 41. In the Figures, a position sensor S 1 (magnetic field sensing proximity switch) for the activation device is shown at the bottom of the upper isolation valve 62 to confirm that the activation device 41 is launched through valve 62 into the pressure isolation passageway 72, so that the bypass sequence can be commenced (i.e., closing of the bypass valve and opening of the bypass line). A second position sensor S2 (magnetic field sensing proximity switch) is shown below the frac head 20 to indicate that the activation device 41 has passed out of the pressure isolation passageway 72, so that the reversal of the bypass sequence can be commenced (i.e., opening of the bypass valve and closing of the bypass line). Examples of position sensors include acoustical sensors (highly sensitive microphone "hearing" the sound of the arrival and travel of the activation device) or magnetic field sensors such as Hall Effect sensors to sense a differential in the electromagnetic field by either a ferrous object or a battery traveling past the sensor. In some embodiments, position sensors for the activation device may be a proximity switch such as magnetic field, infrared, radio frequency identification, or ultrasonic sensors. For magnetic field sensors or magnetic field proximity switch sensors, the activation device 41 may carry a magnet or a battery, or otherwise be formed of a magnetic material to be detected by the sensor / switch. For acoustical sensors, one or more acoustical sensors may be located on one or more components of the staging valve with bypass system 42, the frac tree 10 or the wellhead. For example, an acoustical sensor may be located on a wellhead component (i.e., below the frac tree components), to detect movement of the activation device 41 through the staging valve system 42, through the frac tree 10, and through the wellhead components. As above, other position sensors such as magnetic field sensors (ex. Hall Effect sensors H) may be located on components proximate to the travel of the activation device 41, for example on the bottom connector of the upper isolation valve 62, on the pressure isolation housing 64, on the bottom connector of the frac head 20, and / or on the bottom connector 12 of the frac tree 10.

[0084] One or more pressure sensors P may be included, for example to monitor the pressure in the pressure isolation passageway 72. As shown in FIG. 4D, the pressure sensor P may be located on the connections of the pressure isolation housing 64 to the bleed off valve 70. The pressure sensor P indicates that the bleed off cycle to release pressure / fluid from the pressure isolation passageway 72 may be run, and that it is safe to open the upper isolation valve 62 to launch a first or subsequent activation device 41.

[0085] In some embodiments, flow rate sensors may be included to determine the flow rate through the staging valve with bypass system 42.

[0086] The staging valve with bypass system 42 may include a control system C, remotely located, to control a sequence of opening and closing the valves in response to the valve position sensors V, the one or more position sensors H, detecting movement of the activation device, and the pressure sensor P. The signals / images can be transmitted to a computer, for example located proximate the loading station 44. The operator can be confident that the activation device 41 has been successfully launched or, in the event of a problem in the launch, the operator can be provided with useful location information, pressure information and / or valve position information for the problem.

[0087] Monitoring of progress of the activation device through the launch system 40 can be achieved remotely, by including one or more position indicators, sensors, and / or cameras at, within, or between the loading station 44 and the staging valve with bypass system 42. In some embodiments, the activation device 41 may carry passive triggering features for monitoring by external sensors. For example one or more proximity switch sensors may be provided with access to the loading station 44, the pneumatic line 56, the flange connection 207 of the vented adapter 200, the passageway 208 of the vented adapter 200, and / or to one or more locations along the axial passageway 68 through the staging valve with bypass system 42 to monitor a successful launch through the staging valve with bypass system 42 and into the frac tree 10. In some embodiments, the launch system 40 may include, or be formed with, one or more transparent portions to permit camera monitoring of the progression of the activation device 41. The one or more position indicators, sensors and / or cameras provide one or more signals and / or images indicative of the progression of the activation device 41 at the one or more locations. The signals / images can be transmitted to the control system C, remotely located, for example at the loading station 44. The operator can be confident that the activation device 41 has been successfully launched or, in the event of a problem in the launch, the operator can be provided with useful location information, pressure information and / or valve position information.

[0088] The sequence of staging an activation device 41 with the staging valve system with bypass of this disclosure is shown in FIGS. 7A to 71. In FIG. 7A, before launching and staging an activation device 41, the isolation valves 62, 66 and 104 and bleed off valve 70 are closed, and the activation device is positioned above the upper isolation valve 62. During operations in which a plurality of activation devices are being launched sequentially, one after another, the pressure isolation passageway 72 is generally at a low or zero pressure, and a column of fluid is present in the pressure isolation passageway 72. If this is a first launch, or during automated operation with a control system, the pressure in the pressure isolation passageway 72 is checked with pressure sensor P and pressure is bled off by opening and then closing the bleed off valve 70. Bypass valve 102 in connected supply line 29a is open. Frac fluid is being actively pumped at high pressure from each of the supply lines 29a-29d (arranged as diametrically opposed pairs), into the frac head 20. As a non-limiting example, in an embodiment using four 3", 1502 frac iron supply lines, each rated for 3 m3 / min connected to the frac head 20 in a balanced and diametrically opposed arrangement, a frac fluid flow of 12 m3 / min of fluid is pumped into the wellbore of the wellhead, through the frac head 20. The balanced flow reduces the turbulence within the frac head 20 and reduces wear.

[0089] In FIG. 7B, the upper isolation valve 62 is opened and the activation device is launched by gravity into the pressure isolation passageway 72. The launch of the activation device is successfully confirmed by valve position sensors V and activation device position sensor S 1. The upper isolation valve 62 is then closed, isolating the pressure isolation passageway 72 and the activation device 41 from pressures from above and below (i.e., low or atmospheric pressure in the launch system 40 located above, and high pressure of the frac free 10 located below).

[0090] In FIG. 7C, in order to initiate the bypass, the bypass isolation valve 104 is opened, allowing frac fluid from the connected supply line 29a to begin splitting, that is to begin entering the bypass line 100 and pressurizing the pressure isolation passageway 72. In FIG. 7D, immediately after opening the bypass isolation valve 104, the lower isolation valve 66 is opened. This valve opening sequence is closely timed to avoid pumping high pressure frac fluid against a closed valve. With the valves 104 and 66 in open positions, fully closing the bypass valve 102 fully closes the connected supply line 29a, and fully diverts the frac fluid from the closed and connected supply line 29a into the bypass line 100, into the pressure isolation passageway 72, launching the activation device 41 through the central bore of the frac head 20 and into the frac tree component therebelow (the swab valve 30a in FIG. 7D). As can be seen in FIGS. 7C and 7D, the staging operation with bypass changes the trajectory of the frac fluid from the connected supply line 29a, moving the full volume of the diverted frac fluid flow behind the activation device 41, pushing on the activation device to launch the activation device 41 axially along the pressure isolation passageway 72, through the central bore of the frac head 20, and into the frac tree 10 therebelow. While the bypass line 100 changes the trajectory of the diverted frac fluid, the staging operation maintains flow of the full volume of the diverted frac fluid into the frac head 20. The frac fluid flow volume from supply line 29a is otherwise uninterrupted, but the bypass line changes the trajectory. Frac fluid flow in the supply lines 29b, 29c and 29d is not interrupted. Frac fluid flow in the closed supply line 29a is fully diverted, with a change in trajectory, to launch the activation device, but without interrupting or slowing the frac fluid that is bypassed into the frac head from the connected supply line 29a.

[0091] The staging valve with bypass system 42 avoids prior art issues of slowing or stopping frac fluid flow to launch an activation device, or using a stand-alone pump with additional fluid to launch the activation device. The staging valve with bypass system 42, compared to prior art approaches, reduces the volume of the frac fluid directly entering the frac head from the open supply lines, and diverts a portion of the frac fluid (i.e., from the fully closed supply line) such that it enters the frac head from a different trajectory. This effectively reduces the density of the fluid entering the frac head, making it easier for the activation device to enter the frac stream, without affecting the overall pump rate or total fluid volume being pumped.

[0092] In FIG. 7E, after successful launch of the activation device 41, the bypass valve 102 is opened, and frac fluid flows in a split manner, both in the bypass line 100 and through the connected supply line 29a. The activation device 41 is moved further through the frac tree components.

[0093] In FIG. 7F, to initiate closing of the bypass line 100, the lower isolation valve 66 is closed.

[0094] In FIG. 7G, immediately after closing the lower isolation valve 66, the bypass isolation valve 104 is closed, and frac fluid continues through the connected supply line 29a into the frac head 20, without passing through the bypass line 100. This sequence of opening and closing the valves is automated to avoid pumping high pressure frac fluid against a closed valve. Frac fluid flow remains uninterrupted in any of the supply lines 29b, 29c, and 29d throughout the above staging operations.

[0095] In FIG. 7H, pressure from the pressure isolation passageway 72, with excess fluid, is released by opening the bleed off valve 70, allowing fluid to flow to dump tank 75.

[0096] In FIG. 71, the bleed off valve 70 is closed once the pressure sensor P returns a reading of zero or atmospheric pressure, and the staging system with bypass 42 is ready for the launch of the next activation device 41, by repeating the above sequence.

[0097] FIGS. 5A - 5E show another embodiment of the staging valve system with bypass, shown generally at 42'. Similarly to the embodiment of FIG. 4A, the frac head 20 is of a type having four frac fluid supply lines 29a-29d diametrically opposed and connected to the frac head 20. The staging valve system 42' includes the pressure isolation housing 64, pressure isolation passageway 72 and upper and lower isolation valves 62, 66 similarly to FIG. 4A. However, two frac fluid bypass lines 300, 310 are provided, each one of the bypass lines 300, 310 extending between one of the supply lines 29a or 29c (i.e., diametrically opposed supply lines) and the pressure isolation passageway 72. A bypass valve 302a and 302c, and a bypass isolation valve 304a and 304c are associated with each of the bypass lines 300, 310 respectively. A bleed off valve 70 is connected to the pressure isolation passageway, similarly to FIG. 4A. The staging operations and sequence of valve opening and closing steps are as described above for FIG. 4A-4E, and 7A-7I, except that the supply lines 29a, 29c are closed simultaneously by simultaneously closing bypass valves 302a and 302c, and the bypass lines 300, 310 are closed / opened simultaneously by closing or opening simultaneously bypass isolation valves 304a, 304c. In this way two of the connected supply lines 29a and 29c are closed, and the full frac fluid flow from each of the closed and connected supply lines 20a, 29c is diverted into the bypass lines 300, 310 respectively, and into the pressure isolation passageway 72 to launch the activation device through the frac head 20 and into the frac head component therebelow (swab valve 30a).

[0098] FIGS. 6A - 6C show another embodiment of the staging valve system with bypass shown generally at 42" connected to a frac head 20". The frac head 20" is of a type in which a single frac fluid supply line 400 is connected to the frac head 20". The staging valve system 42" includes a pressure isolation housing 64, a pressure isolation passageway 72 between upper and lower isolation valves 62, 66, and a bleed off valve 70, similarly to the components described in FIG. 4A. A single bypass frac fluid line 410 is connected between the single supply line 400 at one end 410a and the pressure isolation housing 64 at the other end 410b. A bypass valve 402 is connected in the supply line 400, and a bypass isolation valve 404 is connected in the frac fluid bypass line 410 between the bypass valve 402 and the pressure isolation passageway 72. A bleed off valve 70 is connected to the pressure isolation passageway 72. The valves and bypass line 400 in this embodiment are sized and rated to handle the increased pressure and volume of the frac fluid along the single supply line 400. For example, the single supply line 400 may be a single large bore line (7-1 / 16", 15,000 psi, or 5-1 / 8 “, or 4-1 / 16") that delivers higher rates of fluid flow than the four supply lines of FIG. 4A, due to frictional reduction as the fluid interacts with less surface area of the pipe than multiple lines. The staging operation and the sequence of opening and closing the valves is generally as described for FIG. 4A, however, closing the bypass valve 402 diverts the full volume of the frac fluid from the closed supply line 400 into the bypass line 410, through the pressure isolation passage 72 into the frac head 20" and into the frac tree component therebelow (swab valve 30a). Opening and closing bypass isolation valve 404 opens and closes the bypass line 400, as described above for the embodiment of FIG. 4A for bypass line 100.

[0099] As is apparent from the above description, the staging valve with bypass system of this disclosure temporarily borrows one, or multiple, of the frac fluid streams already being pumped through supply line(s) 29 under high pressure to the frac head 20, to bypass the direct trajectory into the frac head 20 that would otherwise be the supply line trajectory, with a valved bypass line which changes the trajectory of the frac fluid flow from the connected supply line (for example 29a) to a trajectory that is behind the activation device 41 (i.e., behind the activation device in the pressure isolation passageway as it moves toward the frac head) when the activation device is in the pressure isolation passageway 72. This pushes the activation device 41 with the frac fluid which is diverted from the connected supply line 29a into the bypass line(s), in order to launch the activation device from the pressure isolation passageway 72 through the frac head 20, into the frac tree 10. The staging valve with bypass system uses existing frac fluid that is already measured and planned to be pumped down the well, without pumping additional fluid to launch the activation device 41. Compared to prior art devices, this has the effect of reducing the amount of fluid needed to be used for any given treatment, reduces the time required to use a stand-alone pump, eliminates the need of the stand-alone pump, and reduces the fluid being disposed of at the end of the frac. The control of the bypass of fracturing fluid is performed in a sequence to avoid both pumping against a closed valve as well as opening a valve to the atmosphere and causing a fluid leak. A logic sequence of achieving bypass of fracturing fluids into a pressure isolation chamber is set out below.

[0100] 1. All valves start in the closed position during initial installation. Before pumping frac treatment fluid through the supply lines to the frac head, the computer control of the remote hydraulic actuation confirms closed position, or closes, the bypass isolation valve(s), bleed off valve and upper and lower isolation valves.

[0101] 2. Pressure test each valve after initial installation.

[0102] 3. Use computer control of hydraulic actuation to open bypass valve(s).

[0103] 4. Rotational valve position sensor to confirm opening of bypass valve(s).

[0104] 5. Valve position sensors to verify closed position of valves listed in step 1.

[0105] 6. Begin pumping frac treatment fluid into the wellbore through the open bypass valve(s) and any other standing frac iron (supply lines) attached to the frac head.

[0106] 7. Verify reading from the pressure sensor that there is zero pressure in the pressure isolation passageway.

[0107] 8. If pressure is greater than zero, use computer control of hydraulic actuation to open bleed off valve.

[0108] 9. Rotational valve position sensor to verify bleed off valve is in the open position.

[0109] 10. Verify pressure relieved to zero pressure in pressure isolation passageway with pressure sensor.

[0110] 11. Use computer control of hydraulic actuation to close bleed off valve.

[0111] 12. Rotational valve position sensor to verify closing of bleed off valve.

[0112] 13. Use computer control system to launch activation device.

[0113] 14. Open upper isolation valve via computer control of hydraulic actuation.

[0114] 15. Linear valve position sensor to verify upper isolation valve is in the open position.

[0115] 16. Launch activation device into pressure isolation passageway from pneumatic launching system via gravity delivery through the open upper isolation valve.

[0116] 17. Verify activation device has passed through the upper isolation valve with position sensor (acoustical or electromagnetic sensor, or proximity switch including magnetic, infrared, radio frequency identification, or ultrasonic).

[0117] 18. Use computer control of hydraulic actuation to close upper isolation valve.

[0118] 19. Linear valve position sensor to verify upper isolation valve is in the closed position. 20. Use computer control of hydraulic actuation to open bypass isolation valve(s) to open bypass line(s).

[0119] 21. Rotational valve position sensor to confirm opening of bypass isolation valve(s).

[0120] 22. Use computer control of hydraulic actuation to open lower isolation valve.

[0121] 23. Linear valve position sensor to confirm opening of lower isolation valve.

[0122] 24. Use computer control of hydraulic actuation to close bypass valve(s).

[0123] 25. Rotational valve position sensor to confirm closing of bypass valve(s).

[0124] 26. Verify activation device has passed from above the lower isolation valve into the frac tree and wellbore with position sensor (acoustical or electromagnetic sensor, or proximity switch including magnetic, infrared, radio frequency identification, or ultrasonic).

[0125] 27. Use computer control of hydraulic actuation to open bypass valve(s).

[0126] 28. Linear valve position sensor to confirm opening of bypass valve(s).

[0127] 29. Use computer control of hydraulic actuation to close lower isolation valve.

[0128] 30. Linear valve position sensor to confirm closing of lower isolation valve.

[0129] 31. Use computer control of hydraulic actuation to close bypass isolation valve(s).

[0130] 32. Rotational valve position sensor to confirm closing of bypass isolation valve(s).

[0131] 33. Repeat steps 7 through 32 for subsequent activation devices to be launched and staged into the wellbore.

[0132] As used herein and in the claims, the word "comprising" is used in its non-limiting sense to mean that items following the word in the sentence are included and that items not specifically mentioned are not excluded. The use of the indefinite article "a" in the claims before an element means that one of the elements is specified, but does not specifically exclude others of the elements being present, unless the context clearly requires that there be one and only one of the elements.

[0133] All references mentioned in this specification are indicative of the level of skill in the art of this invention. All references are herein incorporated by reference in their entirety to the same extent as if each reference was specifically and individually indicated to be incorporated by reference. However, if any inconsistency arises between a cited reference and the present disclosure, the present disclosure takes precedence. Some references provided herein are incorporated by reference herein to provide details concerning the state of the art prior to the filing of this application, other references may be cited to provide additional or alternative device elements, additional or alternative materials, additional or alternative methods of analysis or application of the invention. The terms and expressions used are, unless otherwise defined herein, used as terms of description and not limitation. There is no intention, in using such terms and expressions, of excluding equivalents of the features illustrated and described, it being recognized that the scope of the invention is defined and limited only by the claims which follow. Although the description herein contains many specifics, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the embodiments of the invention.

[0134] One of ordinary skill in the art will appreciate that elements and materials other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such elements and materials are intended to be included in this invention. The invention illustratively described herein suitably may be practised in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein.

Claims

Claims:

1. A staging valve system for staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under the high pressure through one or more supply lines, the staging valve system comprising: a first isolation valve operatively connected to the launching system; a second isolation valve operatively connected to the frac head of the frac tree; a pressure isolation passageway between the first isolation valve and the second isolation valve; the first isolation valve, the second isolation valve and the pressure isolation passageway being axially aligned one with another and with an axial passageway extending through the frac head and into the frac tree to permit passage of the activation device from the low pressure in the launching system to the high pressure in the frac tree; a frac fluid bypass line fluidly connecting at least one of the one or more supply lines to the pressure isolation passageway; a bypass valve in the connected supply line, the bypass valve permitting frac fluid flow to the frac head in an open position, and closing the connected supply line and diverting flow of the frac fluid from the closed supply line into the frac fluid bypass line in a closed position; and a bypass isolation valve in the frac fluid bypass line between the bypass valve and the pressure isolation passageway, the bypass isolation valve preventing frac fluid flow in the frac fluid bypass line when in a closed position, and permitting flow of the diverted frac fluid from the frac fluid bypass line into the pressure isolation passageway when in an open position to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the second isolation valve member and the frac head, and into frac tree components below the frac head.

2. The staging valve system of claim 1, wherein; the one or more supply lines comprises a single frac fluid supply line connected to the frac head; the frac fluid bypass line is fluidly connected between the single frac fluid supply line and the pressure isolation passageway; and the bypass valve fully closes and fully diverts the frac fluid from the single supply line into the frac fluid bypass line in the closed position.

3. The staging valve system of claim 1, wherein:the one or more supply lines comprises a plurality of frac fluid supply lines connected to the frac head; the frac fluid bypass line is fluidly connected between one of the plurality of the frac fluid supply lines and the pressure isolation passageway; and the bypass valve fully closes and fully diverts the frac fluid from the connected fluid supply line into the frac fluid bypass line in the closed position.

4. The staging valve system of claim 1, wherein: the one or more supply lines comprises a plurality of frac fluid supply lines connected to the frac head; a plurality of the frac fluid bypass lines are provided, each one of the frac fluid bypass lines being fluidly connected between one of the plurality of frac fluid supply lines and the pressure isolation passageway; each one of the connected supply lines includes the bypass valve to fully close and fully divert the frac fluid from the connected fluid supply line into the frac fluid bypass line in a closed position; and each one of the frac fluid bypass lines includes the bypass isolation valve.

5. The staging valve system of claim 4, wherein the plurality of frac fluid bypass lines are connected between diametrically opposed fluid supply lines.

6. The staging valve system of claim 5, wherein there are two frac fluid bypass lines.

7. The staging valve system of any of claims 1-6, further comprising a bleed off valve to bleed off pressure from the pressure isolation passageway.

8. The staging valve system of any one of claims 1-7, wherein the activation device is a cylindrical dart, a drone, a ball or a plug.

9. The staging valve system of any one of claims 1-8, wherein the launching system is a pneumatic launching system, and the low pressure in the launching system is an atmospheric pressure.

10. The staging valve system of claim 7, wherein the bleed off valve, the first and second isolation valves, and each one of the bypass and bypass isolation valves are remotely actuated.

11. The staging valve system of claim 10, wherein the bleed off valve, the first and second isolation valves, and each one of the bypass and bypass isolation valves are remotely, hydraulically actuated.

12. The staging valve system of claim 11, further comprising valve position sensors to detect the valve position of the bleed off valve, the first and second isolation valves and the bypass andbypass isolation valves.

13. The staging valve system of claim 12, further comprising one or more position sensors to detect movement of the activation device through the pressure isolation passageway and into the frac tree.

14. The staging valve system of claim 13, wherein the one or more position sensors are acoustic sensors or magnetic field sensors.

15. The staging valve system of claim 13 or 14, further comprising a pressure sensor to detect pressure in the pressure isolation passageway.

16. The staging valve system of claim 15, further comprising a control system to control a sequence of opening and closing the valves in response to the valve position sensors, the one or more position sensors detecting movement of the activation device, and the pressure sensor.

17. A method of staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under high pressure from a single supply line or from a plurality of supply lines, the method comprising: a) launching the activation device from the launching system into a pressure isolation passageway located between first and second isolation valves of a staging valve system connected above the frac head while isolating the pressure isolation passageway from the high pressure in the frac tree with the second isolation valve in a closed position, and then isolating the launching system and pressure isolation passageway with the first isolation in a closed position; and b) closing the single supply line or one or more of the plurality of supply lines and diverting the frac fluid from the closed single supply line or from each of the one or more closed supply lines through a frac fluid bypass line and into the pressure isolation passageway to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the frac head, and into frac tree components below the frac head.

18. The method of claim 17, wherein step b) changes a trajectory of the frac fluid diverted from the closed single supply line or from each of the one or more closed supply lines to a trajectory behind the activation device to push the activation device with the diverted frac fluid generally axially along the pressure isolation passageway and through a central bore of the frac head into the frac tree components below the frac head.

19. The method of claim 17 or 18, wherein step b) includes opening a bypass isolation valve in the frac fluid bypass line, opening the second isolation valve, and closing a bypass valve inthe single supply line or in the one or more of the plurality of supply lines to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the frac head, and into the frac tree components below the frac tree.

20. A method of staging an activation device from a low pressure in a launching system to a high pressure in a frac tree, wherein the frac tree includes a frac head receiving frac fluid under high pressure through one or more supply lines, the method comprising: a) providing a staging valve system operatively connected between the launching system and the frac head of the frac tree, the staging valve system including a first isolation valve, a second isolation valve, and a pressure isolation passageway between the first isolation valve, the second isolation valve, the first isolation valve, the second isolation valve and the pressure isolation passageway being axially aligned one with another and with an axial passageway extending through the frac head and into the frac tree to permit passage of the activation device from the low pressure in the launching system to the high pressure in the frac tree; b) providing a frac fluid bypass line fluidly connecting at least one of the one or more supply lines to the pressure isolation passageway; c) providing a bypass valve in the connected supply line, and a bypass isolation valve in the frac fluid bypass line between the bypass valve member and the pressure isolation passageway; d) with the second isolation valve and the bypass isolation valve in closed positions, opening the first isolation valve to launch the activation device through the first isolation valve into the pressure isolation passageway and closing the first isolation valve; e) opening the bypass isolation valve and the second isolation valve and closing the bypass valve to close the connected supply line and to divert the frac fluid from the closed supply line into the frac fluid bypass line and into the pressure isolation chamber to launch the activation device with the diverted frac fluid, from the pressure isolation passageway, through the second isolation valve and the frac head, and into the frac tree; and f) opening the bypass valve and closing the second isolation valve and the bypass isolation valve to resume frac fluid flow from the previously closed supply line into the frac head and into the frac tree components below the frac head.

21. The method of claim 20, further comprising: g) bleeding off pressure from the pressure isolation passageway and repeating steps d) - f) for launching each subsequent one of a plurality of activation devices.

22. The method of claim 20 or 21, wherein:the one or more supply lines comprises a single frac fluid supply line connected to the frac head, the frac fluid bypass line is fluidly connected between the single frac fluid supply line and the pressure isolation passageway; and the bypass valve fully closes and fully diverts the frac fluid from the single supply line into the frac fluid bypass line in the closed position.

23. The method of claim 20 or 21, wherein: the one or more supply lines comprises a plurality of frac fluid supply lines connected to the frac head; the frac fluid bypass line is fluidly connected between one of the plurality of the frac fluid supply lines and the pressure isolation passageway; and the bypass valve fully closes and fully diverts the frac fluid from the connected fluid supply line into the frac fluid bypass line in the closed position.

24. The method of claim 20 or 21, wherein: the one or more supply lines comprises a plurality of frac fluid supply lines connected to the frac head; a plurality of the frac fluid bypass lines are provided, each one of the frac fluid bypass lines being fluidly connected between one of the plurality of frac fluid supply lines and the pressure isolation passageway; each one of the connected supply lines includes the bypass valve to fully close and fully divert the frac fluid from the connected fluid supply line into the frac fluid bypass line in a closed position; and each one of the frac fluid bypass lines includes the bypass isolation valve.

25. The method of claim 24, wherein the plurality of frac fluid bypass lines are connected between diametrically opposed fluid supply lines.

26. The method of claim 25, wherein there are two frac fluid bypass lines.

27. The method of any one of claims 20-26, wherein the activation device is a cylindrical dart, a drone, a ball or a plug.

28. The method of any one of claims 20-27, wherein the launch step includes launching the activation step pneumatically from an atmospheric pressure.

29. The method of any one of claims 20-28, wherein a bleed off valve from the pressure isolation passageway, the first and second isolation valves, and each one of the bypass and bypass isolation valves are remotely actuated.

30. The method of any one of claims 29, wherein the bleed off valve, the first and second isolation valves, and each one of the bypass and bypass isolation valves are remotely, hydraulically actuated.

31. The method of claim 30, further comprising using valve position sensors to detect the valve position of each of the bleed off valve, the first and second isolation valves and the bypass and bypass isolation valves.

32. The method of claim 29, further comprising using one or more position sensors to detect movement of the activation device through the pressure isolation passageway and into the frac tree.

33. The method of claim 32, wherein the one or more position sensors are acoustic sensors or magnetic field sensors.

34. The method of claim 32 or 33, further comprising using a pressure sensor to detect pressure in the pressure isolation passageway.

35. The method of claim 34, further comprising using a control system to control a sequence of opening and closing the valves in response to the valve position sensors, the one or more position sensors detecting movement of the activation device, and the pressure sensor.

36. A pneumatic launching system for launching an activation device to a staging valve system of one of a plurality of frac trees, comprising: a plurality of loading stations, each loading station being located remotely from the plurality of frac trees; a plurality of pneumatic lines, each pneumatic line having a first end and a second end, the first end connected to one of the plurality of loading stations, and the second end connected to the staging valve system of one of the plurality of frac trees; a carrier adapted to be loaded with the activation device in one of the plurality of loading stations for pneumatically conveying the activation device in one of the plurality of pneumatic lines, the carrier having a generally cylindrical body, at least one closed end, and one or more circumferential seals carried on an outer surface of the carrier to support the carrier within the pneumatic line and to pneumatically convey the carrier through the pneumatic line when air pressure is imparted on the closed end of the carrier; an air source to impart air pressure to the closed end of the carrier when loaded in one of the plurality of loading stations; and an air manifold connecting the air source to each one of the plurality of loading stations, the air manifold including a plurality of control valves to selectively deliver air pressure to oneof the plurality of loading stations in order to selectively launch the activation device to the staging valve system of a selective frac tree of the plurality of frac trees.

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