Patent Application
20220120166
Deep sea or off-shore drilling is performed in many places around the globe to extract oil and gas from subsea reservoirs. In offshore production, platforms used to extract oil from the subsea reservoirs perform a number of functions in order to maintain the subsea reservoir in such a condition that oil and gas can be more easily extracted therefrom. One such function of the platforms is to maintain pressure within the subsea reservoir by pumping processed seawater using a large water pump on the platforms to a subsea injection manifold positioned on the seabed. A conduit, such as a water injection riser, extends from the platforms to the seabed and across the seabed to the manifold to enable the water pump to pump the processed seawater into the subsea reservoir. Water pumps used on platforms typically output sufficient water to enable up to 100,000 barrels per day of water injection into the subsea reservoir.
A few problems exist with current configurations and operations of the platforms with maintaining pressure in the subsea reservoir. One such problem is the size of the hydraulic pumps on the platforms that are meant for large production volumes (e.g., 100K barrels of oil production per day). Another problem is that the cost of installing, moving, and/or maintaining the water pumping infrastructure including the water pump and water injection riser is very expensive and time consuming. As is understood in the art of offshore drilling, oil rigs are routinely moved and oil fields are also dynamic over time. For example, production operations vary for a variety of natural reasons (e.g., weather, seismic, pressure fluctuations, formation shifts, etc.) and manmade reasons (e.g., over-supply, under-supply, price fluctuations, political tensions, war, etc.), so subsea oil fields are routinely developed, slowed, or abandoned.
Moreover, because of the nature of subsea oil production, oil production of a subsea reservoir from a platform may slow or stop altogether. In those events, equipment, such as the water pumps, risers, and other equipment, may not be used for extended periods of time (e.g., weeks, months, years). Such stoppage can be harmful to the equipment and water pumping infrastructure, including the water pump, water injection riser, subsea manifold, filters, fittings, and so forth.
As a result of routine non-operation of oil production by the platforms at subsea reservoirs due to natural and manmade reasons, maintenance is often needed to ensure that all of the equipment and pumping infrastructure, including the water pumps, risers, seabed manifold, etc., properly work. The maintenance of off-shore drilling equipment for subsea reservoirs is often expensive and time consuming. For at least these reasons, there is a need for an alternative solution to existing systems and processes for maintaining subsea reservoirs that is less expensive to install and maintain, and that is more reliable for producers that face oil and gas production variabilities to support pumping water into subsea reservoirs to maintain pressure therein.
To provide for more reliable and cost effective pumping of treated water into a subsea or undersea reservoir so as to maintain or increase pressure therein, a marine vessel including a water pump configured to pump treated seawater may be fluidly connected to a subsea injection manifold fluidly connected to the undersea reservoir. By using a vessel-based water pump and seawater treatment equipment, if production disruption occurs at a subsea reservoir, the vessel may be repositioned to another subsea reservoir so as to continue to operate and avoid problems that occur when water pumps and seawater treatment equipment is not used for extended periods of time.
An adapter structure may be deployed in fluid communication between a first conduit connected to the pump positioned on the marine vessel and a second fluid conduit connected to the manifold. The adapter structure may be a water injection tree, and a second subsea injection manifold or second manifold may be connected thereto such that the second first conduit may be connected to the second manifold. The first conduits may be in the form of (i) drill pipe risers with a flexible jumper, (ii) coiled tubing risers with flexible jumpers, (iii) pipe riser that is flexible (i.e., flexible pipe riser), (iv) or otherwise. In operation, the marine vessel may be a single hulled marine vessel, and may be configured with a stationary positioning propulsion system to enable the marine vessel to remain positioned at the adapter. In being at the adapter, the marine vessel may be positioned above the adapter within a relatively near vertical alignment (e.g., within 50 feet or 100 feet).
In an alternative embodiment, rather than having the water pump and seawater treatment equipment positioned on a marine vessel, the water pump and seawater treatment equipment may be positioned on a seabed near the subsea manifold. To power and/or control operation of the equipment, a marine vessel with power generation and control equipment may be used to deliver power and control signals to the subsea water pump and seawater treatment equipment while positioned thereat. Still yet, the water pump and seawater treatment equipment may be positioned on a seabed near the subsea manifold, and power and control equipment positioned on shore may be used to control the pump and equipment via subsea power and control line cable(s). In this configuration, the riser may be eliminated as the vessel is providing power and control signals to control subsea equipment. This configuration may (1) reduce installation time, (2) enable a smaller vessel to be used, (3) reduce time to recover cables and depart in advance of unanticipated weather storms, and/or (4) provide larger operating windows as only electrical downlines may be connected to subsea equipment on the seafloor.
To provide for mobility, the water pump and water treatment equipment may be positioned on a structure (e.g., skid, floatable structure, or otherwise) that allows for the water pump and water treatment equipment to be easily positioned on the seabed and moved. For example, a crane from a marine vessel may be used to lower and raise the equipment positioned on a skid depending on the configurations of the water pump and water treatment equipment. It should be understood that one or more skids may be utilized depending on the configurations of the water pump and water treatment equipment. In an embodiment, floatation equipment may be positioned on the structure on which the water pump and water treatment equipment is positioned so that an operator may inflate the floatation equipment in order to raise the water pump and water treatment equipment from the seabed, move the equipment from a first manifold, and lower the equipment in a new location to be at a second subsea manifold on the seabed, for example. In an embodiment, a propulsion system may be integrated with the structure to enable the structure to rise or float above the seabed and move via remote control, semi-autonomously, or autonomously to a new location on the seabed.
One process 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.
One embodiment of a system for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas may include a marine vessel with a pump disposed on the marine vessel that is configured to pump water to a subsea manifold in fluid communication with the subsea reservoir. Seawater treatment equipment may be configured to produce treated seawater in preparation for pumping the treated seawater into the subsea reservoir. One or more conduits may be 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.
One process for maintaining or increasing pressure in a subsea reservoir containing oil and/or gas may include positioning a pump on a seabed, where the pump is configured to pump water to a subsea manifold in fluid communication with the subsea reservoir. Seawater treatment equipment may also be positioned on the seabed and be 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. 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 and controller may be positioned at the pump and seawater treatment equipment (e.g., on the water surface thereabove). The electric power generator and controller may be electrically connected to the pump. Seawater may be treated by the seawater treatment equipment 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.
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:
With regard to
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.
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.
With regard to
With regard to
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.
With regard to
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.
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.
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.
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.
With regard to
In this embodiment, rather than a marine vessel 310 including a water pump and water treatment equipment as presented in
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.
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.
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.
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.
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.
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.
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.
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.
This application claims priority to co-pending U.S. Provisional Patent Application having Ser. No. 63/085,859 filed Sep. 30, 2020; the contents of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63085859 | Sep 2020 | US |
