The present invention generally relates to hydrocarbon extraction systems.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Drilling offshore wells traditionally uses surface equipment for the exploitation of subsea petroleum and natural gas deposits. In deep water applications, surface equipment can include floating platforms or vessels (e.g., drill ships).
The surface equipment typically supports risers that extend from one or more wellheads or structures on the seabed to the equipment at the sea surface. The risers connect the subsea well with the surface equipment to protect the fluid integrity of the well and to provide a fluid conduit to and from the wellbore. The risers connecting the surface systems to the subsea wellhead can be thousands of feet long and extremely heavy.
Drilling operations including surface equipment are generally associated with substantial operating costs. In addition, the offshore environment can be difficult for personnel working on the surface equipment or below the surface. Weather often impacts operations and requires that work stop until conditions improve, resulting in time delays and additional costs. The time required to recover defective equipment from the well to the rig and then returned to the well can amount to days. In view of these issues, an alternative approach to deepwater subsea drilling would be beneficial.
Various features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying figures in which like characters represent like parts throughout the figures, wherein:
One or more specific embodiments of the present invention will be described below. These described embodiments are only exemplary of the present invention. Additionally, in an effort to provide a concise description of these exemplary embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
The disclosed embodiments include a subsea hydrocarbon extraction system with a well boring apparatus and a seabed support system. As will be explained in detail below, the seabed support system supports drilling operations, hydrocarbon production, and well shutdown operations from the sea floor. For example, the seabed support system may include multiple modular systems, such as a coiled tubing spool system, blowout preventers (BOP), power generation systems, managed pressure drilling systems, continuous casing systems, water treatment systems, separation systems, drone/robot garages, material storage systems, pump systems, control systems, communication systems, laser system, etc. These modular systems may be supported on one or more platforms or skids on the sea floor. In some embodiments, the seabed support system may include multiple platforms that support one or more wells. These platforms may couple together with tracks and/or other infrastructure (e.g., pipes) enabling materials and equipment to be shared during hydrocarbon extraction operations on multiple wells. In other words, the seabed support system with its variety of modular systems may form a kind of unmanned subsea village capable of supporting all drilling, production, and shutdown operations associated with one or more wells.
The well boring apparatus 12 may be self-propelled, steerable, and launchable from a topside vessel or directly from a seabed support system 14. In some embodiments, the well boring apparatus 12 may be capable of drilling multiple tracks (e.g., wells) from a central borehole. The well boring apparatus 12 may be modular such that it can be configured and then reconfigured for different tasks (e.g., support specific down hole activities). For example, the well boring apparatus 12 may include one or more modules 16 (e.g., 1, 2, 3, 4, 5, or more) such as a cutting/boring module (e.g., a cutter or a grinder), a motor/power module (e.g., a motor and/or a power source), a thrust module (e.g., movable arms configured to engage the wellbore and/or to propel the well boring apparatus), a pump module (e.g., a pump), a cutting processing module (e.g., a container configured to receive cuttings and/or a grinder configured to grind the cuttings), a chemical module (e.g., a container configured to receive and/or to store chemicals, supply chemicals, and/or process chemicals), a casing production module (e.g., pre-cast casing, a frame configured to support precast casing, a container configured to receive and/or to facilitate mixing of cuttings and/or chemicals to form a casing, and/or a frame configured to facilitate deposition of the casing within the wellbore and/or to support formation of casing between the frame and a wall of the wellbore), a laser module (e.g., a laser), a microwave module (e.g., a microwave), a sensor module (e.g., a temperature, pressure, torque, force, depth, angle, speed (rotational and travel), inclination, accelerometer, location, flow rate, gamma ray, nuclear, acoustic, and/or electromagnetic sensor, among others), a plug module (e.g., a plug), a gas handling module (e.g., a container or lines to receive and direct gas), etc.
The cutting/boring module 16 may include a cutting wheel, one or more drill bits 18, and/or a hammer/vibrator capable of cutting and breaking through rock formations. In some embodiments, the subsea hydrocarbon extraction system 10 may include multiple cutting/boring modules 16 each specialized in cutting through different kinds of rock and sediment layers. Accordingly, during drilling operations, the well boring apparatus 12 may be periodically withdrawn in order to exchange one cutting/boring module 16 for another. For example, a cutting/boring module 16 with a drill bit and/or cutting wheel may be substituted for a laser module 16 capable of cutting through rock formations.
In order to drive the boring module 16, the well boring apparatus 12 includes a motor or power module 16 that provides power to drive the boring module 16. The motor or power module may include solid oxide and solid acid fuel cells; energetic materials (e.g., Hydrazine, propellant); aqua batteries (e.g., Lithium-seawater); direct electrical supply from the seabed support system 14 (e.g., through coiled tubing 20 or another connection); direct electrical supply from a rig and/or a ship; indirect electrical supply from a rig, a ship, and/or remotely operated vehicle; and/or hydraulic fluid.
As the cutting/boring module 16 cuts through the rock formation, one or more thrust modules 16 may propel the well boring apparatus 12 further into the well 22. For example, the thrust module 16 may include gripper arms/shoes, tracks, etc. that engage the wall 24 of the well 22 and propel the boring apparatus in axial direction 26. In some embodiments, the well boring apparatus 12 may be propelled by the coiled tubing 20, as the coiled tubing system 28 rotates in circumferential direction 30. In another embodiment, the well boring apparatus 12 may be propelled through a combination of force from the coiled tubing 20 and from the thrust module 16. The coiled tubing 20 may also be used to retrieve the well boring apparatus 12 from the hole as the coiled tubing system 28 rotates in circumferential direction 32. As illustrated, the coiled tubing system 28 may be part of a seabed support system 14, but may also be located at a surface location. The well boring apparatus 12 may also be recovered using a winch and a recovery line on the seabed support system 14 or a surface location (e.g., ship, rig). In some embodiments, the coiled tubing system 28 may assist in providing chemicals used to provide a temporary seal in fluid loss zones as the cutting/boring module 16 cuts through the rock formation. The coiled tubing system 28 may include coiled tubing 20 that is either monochambered for the deployment of fluid to the cutting surface or could be multi-chambered for the deployment of chemicals that upon mixing could be used as a temporary sealant in fluid loss zones.
As the cutting/boring module 16 drills the well 22, a pump module 16 may pump seawater and/or mud to removing the cuttings. The pump module 16 may receive seawater and/or mud through the coiled tubing 20 and/or a separate tubing attachment. In some embodiments, the well boring apparatus 12 may include a grinding module 16 that grinds the cuttings to facilitate transport to the seabed support system 14 and/or for production of a casing surrounding the well 22. For example, the well boring apparatus 12 may include a casing production module 16 that produces a casing/lining using the ground cutting paste produced by the grinding module 16, and chemicals (e.g., pre-polymers and photo initiators such as acrylate and methacrylate monomers) stored in a storage container of a chemical module 16. The casing may then be cured with a curing module (e.g., microwave component, ultraviolet light component, etc.). However, in some embodiments, the casing/lining production module may grind the cuttings, combine the cuttings with chemicals into a casing/lining, and then cure the casing/lining; instead of using separate modules. In some embodiments, the casing production module(s) 16 may include a material ready to produce the casing (e.g., cement) and/or receive it from an external source (e.g., from the seabed support system 14 through the tubing spool 20). In some embodiments, the casing production module 16 may include preformed casing/lining sections that are installed as the well boring apparatus 12 progresses towards the hydrocarbon reservoir.
Once the well boring apparatus 12 reaches the hydrocarbon reservoir, the well boring apparatus 12 may enable oil and/or natural gas production by cutting through the casing with a laser module 16. In another embodiment, the well boring apparatus 12 may include a water jet-cutting module 16 that is likewise able to cut through the casing/lining to begin production. The laser module 16 and/or water jet module may also prepare the casing (e.g., cut the casing) for hydraulic fracturing. For example, in a hydraulic fracturing situation, the well boring apparatus 12 may cut through the casing with either a laser module 16 or a water jet-cutting module 16 (e.g., a waterjet cutter). Once cut, the well boring apparatus 12 may use a plug module 16 to plug the well 22 before frac fluid is pumped into the well 22 during hydraulic fracturing operations.
As discussed above, the well boring apparatus 12 may include one or more chemical modules 16 that store chemicals to form the casing. In some embodiments, the chemical module(s) 16 may store additional chemicals to facilitate drilling and production operations. For example, the chemical modules 16 may store chemicals that inhibit hydrate formation and chemicals that enable hydrocarbon production by dissolving methane hydrates (e.g., release the gas in methane hydrates by the use of exothermic reactions) as the well boring apparatus 12 drills. The modules 16 may also store chemicals such as acids, hydrate inhibitors, scale inhibitors, biocides, thermite, eutectic materials (e.g., bismuth alloys that can be used as temporary or permanent sealants), among others. These chemicals may also be pumped from the subsea support system 14 through coiled tubing 20 to replenish module(s) 16 on the well boring apparatus 12 and/or directly into the well 22 through the well boring apparatus 12.
The well boring apparatus 12 may also include other module(s) 16 to assist in drilling and production operations (e.g., melt methane hydrates, inhibit hydrate formation). For example, the well boring apparatus 12 may include a heating module (e.g., a heat source) that inhibits hydrate formation and releases gas from methane hydrates. In some embodiments, the well boring apparatus 12 may include an acoustic energy module (e.g., an acoustic energy source) that breaks up methane hydrates for production as well as inhibits formation of hydrates. Moreover, the well boring apparatus 12 may include a microwave module that releases gas from methane hydrates and inhibits hydrate formation in the well 22.
In order to steer and measure properties in the well 22, the well boring apparatus 12 may include a sensor and/or control module 16 with one or more sensors. For example, the sensor module 16 may include a temperature, pressure, torque, force, depth, angle, speed (rotational and travel), inclination, accelerometer, location, flow rate, gamma ray, nuclear, acoustic, and electromagnetic sensors among others. The sensor and/or control module 16 may also include navigation tools such as an inertial navigation system that guides the well boring apparatus 12. The sensors also may enable the well boring apparatus 12 to analyze properties of the surrounding environment such as temperature, pressure, acidity, and for the presence of particular chemicals, as well as steer the well boring apparatus 12. Accordingly, the direction of the well bore may be changed at any time during the drilling process. In some embodiments, the steering control signals may be provided from a surface location, the seabed support system 14, and/or a preloaded mission package. In some embodiments, the direction of drilling can be manipulated by changing characteristics of the cutting wheel or bits 18 that contact the formation (e.g., changing the location, number, or type of teeth, the angle of the cutting wheel relative the formation, the portions of the cutting wheel in contact with the formation, etc.). In some embodiments, the thrust module 16 may be used to control the direction of travel, or a combination of the thrust module 16 and the cutting wheel or bit(s) 18.
In order to launch, recover, and selectively change the modules 16, the subsea hydrocarbon extraction system 10 may include a launch and recovery frame 34 that aligns the well boring apparatus 12 for insertion into the well 22 through the wellhead 36. In some embodiments, the frame 34 may couple to the well boring apparatus 12 to enable a drone or robot 38 to change the configuration of the well boring apparatus 12 (e.g., selectively coupling and uncoupling modules 16 from the well boring apparatus 12). As illustrated, the wellhead 36 may couple to a multi-port wellhead connection 39 that includes multiple conduits 40 that enable insertion of the well boring apparatus 12, insertion of additional tools into the well 22, as well as fluid processing of fluid (e.g., drilling mud, water, hydrocarbons, etc.) coming out of the well 22. For example, the wellhead 36 may include a main conduit 42 that enables insertion of the well boring apparatus 12 into the wellhead 36. Coupled to the main conduit 42 are second and third conduits 44 and 46. The second and third conduits 44, 46 may enable insertion of additional tools following insertion of the well boring apparatus 12, as well as fluid processing. For example, the secondary conduit 44 may direct fluid to a production tree as it flows out of the well 22, while the third conduit 46 may enable tool insertion and/or chemical injection. To control fluid flow out of the multi-port wellhead connection 39, the multi-port wellhead connection 39 may couple to various blowout preventers 48 that control access to the well 22.
The modular systems 58 may be installed and retrieved directly by lowering and retrieving the platform 60 and/or with the use of a remotely operated vehicle or an autonomous underwater vehicle. Moreover, the seabed support system 14 may be deployed from a construction vessel rather than a conventional drilling unit. For example, the platform 60 and/or modular systems 58 may be secured using ball and taper units that allow for quick-release disconnection by remotely operated vehicle as well as retrieval for maintenance and/or replacement.
In order to power the seabed support system 14 and/or the well boring apparatus 12, the power generation system 66 may generate and/or store power. The power generation system 66 may produce power in various ways including subsea turbines (e.g., water/hydro turbines), nuclear, fuel cells, energetic materials (such as hydrazine, propellants), and/or thermal conversion. The power generation system 66 may also store power produced on the surface (e.g., wind power system, wave power system, rig, ship, etc.) using batteries and/or provide a connection for external power to flow to the subsea hydrocarbon extraction system 10. For example, the power generation system 66 may electrically couple to a ship 82 that produces power (e.g., power generation ship). The ship 82 then transfers power to the subsea hydrocarbon extraction system 10 through power line(s) 84 (e.g., umbilical lines). In some embodiments, the power generation system 66 may couple to subsea cables that carry power from a shore facility. As the power generation system 66 receives power, it distributes the power throughout the subsea support system 14 and/or stores the power in batteries for later use (e.g., during a storm).
As the well boring apparatus 12 drills the well 22, pump systems 72 may pump water, chemicals, and/or drilling mud into the well 22 to remove cuttings (e.g., rock, sand, etc.), to hydraulically fracture the well, or otherwise facilitate drilling operations. Moreover, as the well boring apparatus 12 drills, the water, drilling mud, chemicals, etc. may mix with natural gas and/or oil. However, instead of processing the cuttings, water, chemicals, drilling mud, etc. at the surface, the subsea hydrocarbon extraction system 10 may process these materials at the seabed with the seabed support system 14, thereby removing the need for a drilling riser. In order to process the fluids exiting the well 22, the seabed support system 14 may include a separator system 70 that separates oil and/or natural gas from the water, chemicals, and/or mud exiting the well 22. The oil and/or natural gas may then be pumped through pipelines 86 to the surface or along the sea floor to the shore for further processing and refining. After separating the water, gas, and oil in the separator system 70, the seabed support system 14 may also treat the water in a water treatment system 68 for reuse in the well 22 or for release into the surrounding environment (e.g., desalination, disinfection, etc.).
Similarly, instead of pumping drilling mud, frac fluid, etc., from the surface the seabed system 14 may include material storage systems 74 with storage tanks, racks, etc. These storage systems 74 may store a variety of materials such as water, chemicals, proppant, cement, fishing heads (e.g., for retrieving stuck pipes or equipment), pipes, thermite (e.g., to form temporary or permanent zonal seals in the well 22 as well as wellhead isolation), bismuth alloy, etc. for use by the hydrocarbon extraction system 10. The tanks may in turn couple to mixer systems 78 that combine water, chemicals, proppant, cement, etc. that is then pumped into the well 22 using pumps 76 (e.g., drilling mud pumps, frac pumps, etc.). The mixer systems 78 may also combine chemicals, water, etc. for use in the modules 16 of the well boring apparatus 12.
As explained above, the well boring apparatus 12 may include one or more modules 16 that facilitate drilling of the well 22. These modules 16 enable the well boring apparatus 12 to be reconfigured to perform different activities. In order to exchange and/or change out the modules 16, the seabed support system 14 may include drones/robots 38 that move modules 16 around the platform 60 as well as change the configuration of the well boring apparatus 12. The drones/robots may also manipulate other equipment and systems 58. For example, the drones/robots 38 may perform repairs on the seabed support system 14, replace equipment or systems 58, lay pipes, lift pre-formed casing into the well 22, etc. When the drones/robots 38 are not in use or when the robots/drones 38 need maintenance (e.g., battery charging, refueling) the drones/robots 38 may be relocated to a drone/robot garage(s) 72 that recharges batteries, downloads data, uploads missions, etc.
The seabed support system 14 may also include control and communication system modules 80, 81 that control operation of the seabed support systems 58, well boring apparatus 12, and drones/robots 38. For example, the control system modules 80 (e.g., a control system having an electronic controller, processor, and memory) may be in signal communication (fluid, optical, electrical, wireless, acoustic, radio, inductive, and/or magnetic) with one or more modular systems 58 (e.g., sensors and/or controllers coupled to the modular systems 58), well boring apparatus 12, and one or more drones/robots 38. In some embodiments, the control system module 80 may also receive feedback from video cameras (e.g., visual, infrared, thermal) positioned around the subsea support system 14. In this way, the control system module 80 enables monitoring and control of hydrocarbon extraction operations (e.g., drilling, production, and well abandonment operations). For example, the control system module 80 may control permanent or zonal sealing of the well 22 during drilling as well as wellhead isolation once production is complete. The control system module 80 may use the well boring apparatus 12 and modules 16 (e.g., chemical modules 16 with thermite, and/or bismuth alloys) to form the seals. In some embodiments, the control system module 80 may control other equipment (e.g., cranes) on the subsea support system 14 to deploy thermite, explosives, bismuth alloys, etc. to form temporary or permanent seals (e.g., zonal seals) in the well 22. Moreover, the control system module 80 may communicate with remote operators (e.g., shore, rig, ship, etc.) by providing video feed, sensor data, etc. Thereby, enabling operators to monitor and control operation of the subsea hydrocarbon extraction system 10 remotely.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/216,872, filed Sep. 10, 2015, entitled “SUBSEA HYDROCARBON EXTRACTION SYSTEM,” which is incorporated by reference herein in its entirety for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/051111 | 9/9/2016 | WO | 00 |
Number | Date | Country | |
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62216872 | Sep 2015 | US |