VESSEL-BASED WATER INJECTION SYSTEMS

Abstract

A marine vessel may be configured with a water pump and seawater treatment equipment for use in providing a marine vessel water pumping platform for pumping water into a subsea reservoir to help maintain or increase pressure to assist with producing oil and/or natural gas. The marine vessel water pumping platform allows for the pump and seawater treatment equipment to be continuously used for pumping operations as the marine vessel may be moved between subsea reservoir sites, which helps reduce maintenance costs. The water pump may be lower in minimal flow capacity than water pumps on platforms, thereby allowing for more diversity in supporting different oil and/or gas pumping in offshore drilling operations.

Claims

1. A method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said method comprising: positioning a marine vessel including a pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir at the subsea manifold; treating seawater by seawater treatment equipment to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir; and pumping, by the pump, the treated seawater through one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.

2. The method according to claim 1, wherein positioning the marine vessel includes dynamically positioning the marine vessel in a substantially fixed location.

3. The method according to claim 1, further comprising: fluidly connecting a water conduit injection tree to the subsea manifold in fluid connection with the subsea reservoir; and fluidly connecting a conduit between the water injection pump and the water conduit injection tree.

4. The method according to claim 3, further comprising: disconnecting the water conduit injection tree from the subsea manifold; and fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.

5. The method according to claim 1, wherein fluidly connecting a conduit includes fluidly connecting a drill pipe riser and flexible jumper.

6. The method according to claim 1, wherein fluidly connecting a conduit includes fluidly connecting at least one pair of a coiled tubing riser and flexible jumper.

7. The method according to claim 1, wherein fluidly connecting a conduit includes fluidly connecting a flexible pipe riser.

8. A system for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said system comprising: a marine vessel; a pump disposed on the marine vessel and configured to pump water to a subsea manifold in fluid communication with the subsea reservoir; seawater treatment equipment configured to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir; and one or more conduits in fluid communication with the pump and subsea manifold to enable the treated seawater to be pumped therethrough by the pump to cause fluid pressure in the subsea reservoir to be maintained or increased.

9. The system according to claim 8, wherein positioning the marine vessel includes a propulsion control system configured to dynamically position the marine vessel in a substantially fixed location when the pump is pumping the treated seawater.

10. The system according to claim 8, further comprising: a water conduit injection tree configured to the subsea manifold in fluid connection with the subsea reservoir; and a conduit fluidly connected between the water injection pump and the water conduit injection tree.

11. The system according to claim 10, wherein: the conduit is fluidly disconnected from the pump and the water conduit injection tree from the subsea manifold; and the conduit being fluidly connected between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.

12. The system according to claim 8, wherein the conduit includes a drill pipe riser and flexible jumper.

13. The system according to claim 8, wherein the conduit includes a drill pipe riser and flexible jumper.

14. The system according to claim 8, wherein the conduit includes at least one pair of a coiled tubing riser and flexible jumper.

15. The system according to claim 8, wherein the conduit includes a flexible pipe riser.

16. A method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas, said method comprising: positioning a pump on a seabed, the pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir; positioning seawater treatment equipment on the seabed, the seawater treatment equipment configured to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea manifold to the subsea reservoir; fluidly connecting the pump and seawater treatment equipment together; fluidly connecting the pump to the subsea manifold through one or more conduits; positioning a marine vessel including an electric power generator at the pump and seawater treatment equipment; electrically connecting the electric power generator to the pump; treating seawater by the seawater treatment equipment to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea reservoir; and pumping, by the pump, the treated seawater through the one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.

17. The method according to claim 16, wherein positioning the marine vessel includes dynamically positioning the marine vessel in a substantially fixed location.

18. The method according to claim 16, further comprising: fluidly connecting a water injection tree to the subsea manifold in fluid connection with the subsea reservoir; and fluidly connecting a conduit between the water injection pump and the water injection tree.

19. The method according to claim 18, further comprising: disconnecting the water conduit injection tree from the subsea manifold; and fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir.

20. The method according to claim 16, further comprising mounting the pump onto a skid for deployment to the seabed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Illustrative embodiments of the present invention are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:

[0014] FIGS. 1A-1C are illustrations of a subsea reservoir site with a marine vessel configured with a water pump and water treatment equipment for pumping treated water from the marine vessel to a subsea manifold for pumping into a subsea reservoir with oil and/or natural gas to maintain or increase pressure for producing the oil and/or natural gas by a platform;

[0015] FIG. 2 is an illustration of two subsea reservoir sites in which a marine vessel configured with a water pump and water treatment equipment for pumping treated water from the marine vessel is moved from a first subsea reservoir site to a second subsea reservoir site; and

[0016] FIG. 3 is an illustration of a subsea reservoir site in which a subsea water pump and water treatment equipment may be deployed on the seabed and fluidly connected to a subsea manifold that is in fluid connection with a subsea reservoir, and a marine vessel with an electric generator and controller for powering and controlling the subsea pump and water treatment equipment.

DETAILED DESCRIPTION OF THE INVENTION

[0017] With regard to FIG. 1A, an illustration of an illustrative scene 100a of a region in which off-shore production is taking place at a platform 102 at a subsea reservoir (not shown) including oil and/or gas beneath a seabed 104. A subsea manifold 106 is shown to be positioned on the seabed 104 and is in fluid connection with the subsea reservoir. The platform 102 may include a water pump (not shown) and water treatment equipment (not shown) positioned thereon (not shown). Typically, the water pump would be in fluid communication with the subsea manifold 106 via a water injection riser (not shown), as understood in the art, that extends vertically to the seabed 104 and across the seabed 104 to connect to the subsea manifold 106. However, in accordance with the principles described herein, the water pump and water treatment equipment may be eliminated and replaced by a marine-vessel based water pump or subsea water pump. As understood, the water pump typically positioned on the platform 102 is configured to pump treated water from the platform 102 to the subsea manifold 106 for injection into the subsea reservoir. As understood in the art, the water pump on platform 102 is configured for large volume pumping, such as 100K barrels per day or more.

[0018] As an alternative and/or in addition to utilizing a water pump positioned on the platform 102, a marine vessel 110 that includes a water pump 112 and water treatment equipment 114 positioned on the marine vessel 110 may be utilized. The water pump 112 may be configured to pump lower volumes, such as 30K barrels/day, than the water pump on the platform 102. By utilizing a lower volume pump, smaller sized subsea reservoirs and/or lower desired pump volumes may be serviced by the marine vessel 110. The water pump 112 and water treatment equipment 114 may be fluidly connected to one another on the marine vessel 110. The water treatment equipment 114 may be configured with filters to remove shells, sand, algae, and other impurities that is pumped into the water treatment equipment 114. In addition, the water treatment equipment 114 may deoxygenate the seawater to avoid corrosion and bacteria growth. Other water treatment processes may be utilized, as well.

[0019] As further shown, a water injection tree 116 may be positioned on the seabed 104 and be fluidly connected to the subsea manifold 106 by a conduit 118. In an embodiment, a subsea injection manifold 120 may be connected to or in fluid connection with the water injection tree 116. In an embodiment, the water pump may be in fluid connection with the water injection tree 116 via the subsea injection manifold 120 by a drill pipe riser 122 and flexible jumper 124. It should be understood that additional fittings and conduits not specifically shown may be utilized.

[0020] With regard to FIG. 1B, an illustration of an illustrative scene 100b of a region in which off-shore production including oil and/or gas beneath the seabed 104 is taking place via the platform 102 at the subsea reservoir (not shown). In this embodiment, the marine vessel 110 with the water pump 112 and water treatment equipment 114 may be fluidly connected to the water injection tree 116 via at least one cooling tubing riser 126 and flexible jumper(s) 128. As shown, the coiled tubing riser(s) 126 and flexible jumper(s) 128 may fluidly connect to the subsea injection manifold 120.

[0021] With regard to FIG. 1C, an illustration of an illustrative scene 100c of a region in which off-shore production is taking place via the platform 102 at the subsea reservoir (not shown) including oil and/or gas beneath the seabed 104. In this embodiment, the marine vessel 110 with the water pump 112 and water treatment equipment 114 may be fluidly connected to the water injection tree 116 via at least one flexible pipe riser 130, such as a Magma pipe riser, that has at least a flexible portion.

[0022] In operation, the marine vessel 110 may be configured with a propulsion controller and propulsion system that performs dynamic positioning to maintain the marine vessel 110 in a substantially stationary position (e.g., within 3 feet). Stationary positioning the marine vessel 110 may be performed by using a global positioning system (GPS) and/or local positioning system (e.g., relative to a fixed structure or land marker), for example, that uses wireless RF communications or optical communications, for example. Still yet, the propulsion controller may be configured to utilize various sensor data, including gyro rotational, accelerometers, and so forth, and provide automatic feedback to cause thrusters to be maintained in a substantially fixed position. Although one marine vessel 110 is shown, it should be understood that multiple marine vessels with a water pump and water treatment equipment that are fluidly connected to the water connection tree 116 may be utilized during pumping operation.

[0023] With regard to FIG. 2, an illustration of scenes 200 of multiple subsea reservoir sites #1 and #2 is shown. In the scenes 200, two different platforms 202a and 202b (collectively 202) are shown to be pumping oil and/or natural gas at each of the different subsea reservoir sites from the subsea reservoirs. Seabeds 204a and 204b may have subsea manifolds 206a and 206b positioned thereon that are in fluid connection with the subsea reservoirs. As previously described, water injection risers had historically been used by pumps and sea water treatment equipment on off-shore platforms 202 to fluidly connect the water pumps with the subsea manifolds 206a and 206b. However, by using marine vessel-based water pumps and/or seawater treatment systems, the cost of using large water pumps on the platforms 202a and 202b may be avoided.

[0024] As shown, a marine vessel 210 that includes a water pump 212 and water treatment equipment 214 may in a first instance connect to a first water injection tree 216a that is in fluid connection with the subsea manifold 206a via a first conduit 218a. In an embodiment, the water pump 212 may be in fluid connection with a subsea injection manifold 220a in fluid connection with the water injection tree 216a via a conduit, in this case drill pipe riser 222a and flexible jumper 224a. As previously provided, alternative conduits may be utilized. Because the water pump 212 and water treatment equipment 214 are marine vessel-based, in the event that the first platform 202a is shut down for maintenance or the subsea reservoir having a problem or simply being discontinued from being pumped, the marine vessel 210 may be disconnected from the subsea injection manifold 220a and/or drill pipe riser 222a and flexible jumper 224a, and moved from the subsea reservoir site #1 to the subsea reservoir site #2. The water pump 212 may thereby be fluidly connected to the subsea manifold 206b via water injection tree 216b, conduit 218b, and subsea injection manifold 220b via a drill pipe riser 222a and/or flexible jumper 224b. The use of the marine vessel based water pump 212 and water treatment equipment 214 allows for lower cost operations since platform-based water pumps that are more expensive for operation and maintenance are no longer needed.

[0025] One embodiment of a method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas may include positioning a marine vessel including a pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir at the subsea manifold. Seawater may be treated by seawater treatment equipment to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir. The pump may pump the treated seawater through one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.

[0026] Positioning the marine vessel may include dynamically positioning the marine vessel in a substantially fixed location (e.g., maintained within 3 feet). The process may further include fluidly connecting a water conduit injection tree to the subsea manifold in fluid connection with the subsea reservoir, and fluidly connecting a conduit between the water injection pump and the water conduit injection tree. In an embodiment, the process may include disconnecting the water conduit injection tree from the subsea manifold, and fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir. That is, the marine vessel moves to a different subsea reservoir so the water pump and conduit is transferred from a first to a second subsea manifold and equipment connecting thereto.

[0027] In an embodiment, fluidly connecting a conduit may include fluidly connecting a drill pipe riser and flexible jumper. Alternatively, fluidly connecting a conduit may include fluidly connecting at least one pair of a coiled tubing riser and flexible jumper. Still yet, fluidly connecting a conduit may include fluidly connecting a flexible pipe riser.

[0028] With regard to FIG. 3, an illustration of an illustrative scene 300 of a region in which off-shore production is being performed by a platform 302 at a subsea reservoir (not shown) including oil and/or gas beneath a seabed 304. A subsea manifold 306 is shown to be positioned on the seabed 304 and is in fluid connection with the subsea reservoir. The platform 302 may include a water pump (not shown) and water treatment equipment (not shown) positioned thereon. The water pump may be in fluid communication with the subsea manifold 306 via a water injection riser 308 that extends vertically to the seabed 304 and across the seabed 304 to connect to the subsea manifold 306. As understood, the water pump positioned on the platform 302 is configured to pump water treated water from the platform 302 to the subsea manifold 306 for injection into the subsea reservoir.

[0029] In this embodiment, rather than a marine vessel 310 including a water pump and water treatment equipment as presented in FIGS. 1A-1C, a subsea water pump 312 and optionally water treatment equipment 313 may be positioned on the seabed 304 for use in pumping treated water. The subsea water pump 312 may be configured to pump lower volumes, such as 30K barrels/day, than the water pump on the platform 302. By utilizing a lower volume pump, smaller sized subsea reservoirs and/or lower desired pump volumes may be serviced by the marine vessel 310. It should be understood that multiple water pumps may be positioned on the seabed 304 in series or in parallel with respect to the subsea manifold 306. The water pump 312 and water treatment equipment 313 may be directly or indirectly fluidly connected to one another.

[0030] To power the subsea water pump 312, an electricity power generator and controller 314 may be positioned on the marine vessel 310. The generator and controller 314 may be configured using any means to generate electricity, including burning natural gas, solar power, or any other “green” or “non-green” electricity production system, as understood in the art, and generate control signals for controlling operation of the subsea water pump 312. A power line or cable 315 may be electrically connected to the generator 314 and extended from the marine vessel 310 down to the subsea water pump 312 to power and control the subsea water pump 312. That is, electrical power may be applied to the subsea water pump 312 and control signals may control operation of the water pump. The control signals may cause the pump to turn ON and OFF. In an embodiment, the controller may also be used to control different aspects of the pump, such as controlling different pistons at different timing offsets. Moreover, sensor signals from the pump and/or seawater treatment equipment may be communicated back to the controller for monitoring and controlling the pump and treatment equipment.

[0031] As further shown, a water injection tree 316 may be positioned on the seabed 304 and be fluidly connected to the subsea manifold 306 by a conduit 318. In an embodiment, a subsea injection manifold 320 may be connected to or in fluid connection with the water injection tree 316. In an embodiment, the subsea water pump 312 may be in fluid connection with the water injection tree 316 via the subsea injection manifold 320 by a drill pipe riser 322. It should be understood that additional fittings and conduits not specifically shown may be utilized.

[0032] In an embodiment, the subsea water pump 312 may be disposed on a skid 324 that enables the subsea water pump 312 to be placed on the seabed 304 along with providing a platform for a crane 326 on the marine vessel 310 to raise and lower the subsea water pump 312. In an embodiment, seawater treatment equipment may be positioned on the same or different skid 324 as the subsea water pump 312. In an embodiment, a ballast and/or inflatable flotation device 326 along with an air pump 328 may be mounted to the skid 324, for example, to enable the skid 324 and subsea water pump 312 to be more easily lifted and/or moved from one location to another either below or above the surface of the water. In an embodiment, a propulsion system (e.g., motor, propeller(s), direction actuator(s), etc.) may be integrated with the structure to enable the structure to rise or float above the seabed, optionally below the surface of the water, and move via remote control, semi-autonomously, or autonomously to a new location on the seabed.

[0033] One embodiment of a method for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas may include positioning a pump configured to pump water to a subsea manifold in fluid communication with the subsea reservoir on a seabed. Seawater treatment equipment configured to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea manifold to the subsea reservoir on the seabed may be positioned. The pump and seawater treatment equipment may be fluidly connected together. The pump may be fluidly connected to the subsea manifold through one or more conduits. A marine vessel including an electric power generator may be positioned at the pump and seawater treatment equipment. The electric power generator may be electrically connected to the pump. The seawater treatment equipment may treat the seawater to produce treated seawater in preparation for the pump to pump the treated seawater into the subsea reservoir. The pump may pump the treated seawater through the one or more conduits in fluid communication with the subsea manifold to cause fluid pressure in the subsea reservoir to be maintained or increased.

[0034] In an embodiment, positioning the marine vessel includes dynamically positioning the marine vessel in a substantially fixed location. The process may further include fluidly connecting a water injection tree to the subsea manifold in fluid connection with the subsea reservoir, and fluidly connecting a conduit between the water injection pump and the water injection tree.

[0035] The process may further include disconnecting the water conduit injection tree from the subsea manifold, and fluidly connecting the conduit between the pump and a second subsea manifold in fluid connection with a second subsea reservoir. The process may further include mounting the pump onto a skid for deployment to the seabed. The skid may include dynamic flotation to assist raising, lowering, and/or moving the pump and/or water treatment equipment.

[0036] While a marine vessel based water pump and water treatment equipment solution and seabed based water pump and water treatment equipment solution have been presented, it should be understood that alternative solutions are possible. For example, the marine vessel is shown to be a manned marine vessel. However, it should be understood that an unmanned marine vessel (e.g., drone marine vessel) may be utilized by using a remote control of the unmanned marine vessel, generator, local controller, water pump, and water treatment equipment. Unmanned marine vessels may include the same or similar controllers and propulsion systems to maintain the unmanned marine vessel in substantially stationary locations. Still yet, rather than using a marine vessel, power and control signals from land may be provided and remote control of the subsea water pump and water treatment equipment may be provided. Other manned and unmanned configurations are possible along with alternative configurations of vessel-based, drone vessel-based, and subsea water pump and/or water treatment equipment.

[0037] The previous description is of at least one embodiment for implementing the invention, and the scope of the invention should not necessarily be limited by this description. The scope of the present invention is instead defined by the following claims.