Underwater production system

Abstract

The utility model relates to the technical field of ocean oil and gas engineering, in particular to an underwater production system which comprises a base, an oil and gas main pipe, a Christmas tree branch pipe, a well drilling guide pipe, a Christmas tree, a jumper pipe, a fly line and the like. The base is composed of a suction pile, a sinking and floating control assembly and a supporting structure located on the upper portion of the suction pile. The well drilling guide pipe is arranged on the base; the Christmas tree is detachably installed on the well head installed later in the well drilling guide pipe, and the Christmas tree is communicated with the well head, the jumper pipe and the pre-installed or post-installed fly line. The oil gas main pipe, the Christmas tree branch pipe, the well drilling guide pipe, the Christmas tree, the jumper pipe, the fly line, the sinking and floating control assembly and the like are integrated on the base to form a compact integral underwater production system, and the sinking and floating control assembly and the suction pile are used for driving the system to sink and float when the Christmas tree is separated from a well head. The system is then installed and recovered so that the system can be reused, thereby reducing the development cost of an oil field, especially a marginal oil field.

Description

Technical Field

[0001] The embodiments of the present utility model relate to the technical field of offshore oil and gas engineering, and particularly to an underwater production system. Background Art

[0002] An underwater production system refers to a production system that uses underwater completion technology combined with facilities such as fixed platforms and floating production platforms to form different offshore oilfield development forms, and is one of the key technologies for offshore oilfield development.

[0003] However, during the use of currently commonly used underwater production systems, most of them are used once, that is, they are fixedly operated for a long time after installation until they are discarded and no longer recycled and reused, resulting in a relatively large fixed asset investment for the development of an oil and gas field. Therefore, for the development of shallow marginal oil and gas fields (generally referring to those oil and gas fields with small reserves and in remote areas), if a conventional underwater production system is used for development, it will be difficult to start due to poor economic efficiency. Summary of the Utility Model

[0004] In view of the above problems, the embodiments of the present utility model provide an underwater production system that overcomes or at least partially solves the above problems.

[0005] According to one aspect of the embodiments of the present utility model, an underwater production system is provided, including a base, a drilling conduit, and a Christmas tree. The base is composed of at least two suction piles, a sinking and floating control component, and a support structure located above the suction piles; the drilling conduit is pre-set in the base; the Christmas tree is detachably and post-installed on a post-installed wellhead inside the drilling conduit, and the Christmas tree is connected to the wellhead, a post-installed crossover pipe, and a pre-installed or post-installed flying line.

[0006] In some embodiments, the underwater production system includes a pre-installed oil and gas main pipe and a pre-installed Christmas tree branch pipe. One end of the Christmas tree branch pipe is connected to the Christmas tree through a detachable post-installed crossover pipe, and the other end of the Christmas tree branch pipe is connected to the pre-installed oil and gas main pipe; at least one of a valve, a flow meter, a chemical reagent injection hole, a temperature and pressure sensor, and a sand production monitor is pre-installed on the oil and gas main pipe and the Christmas tree branch pipe.

[0007] In some embodiments, the pre-installed oil and gas main pipe is detachably connected to a subsea pipeline outside the base.

[0008] In some embodiments, the sinking and floating control assembly includes a single suction pump control manifold and a suction pile pipeline pre-installed on the base. One end of the single suction pump control manifold is provided with a suction pile pipeline connection port, and the number of the suction pile pipeline connection ports is the same as the number of the suction piles. The suction pile pipeline connection ports are connected to the suction piles through the pre-installed suction pile pipelines, and the other end of the single suction pump control manifold is used to connect to a single suction pump during underwater installation or recovery.

[0009] In some embodiments, pipeline valves are pre-installed on the suction pile pipelines, and the pipeline valves are used to control the closing and opening of the suction pile pipelines and the flow rate of the suction pile pipelines.

[0010] In some embodiments, the subsea production system includes a umbilical cable terminal installed on the base later. The umbilical cable terminal is connected to the Christmas tree through a pre-installed or later-installed jumper cable to transmit electric power, communication signals, hydraulic oil, and chemical agents to the Christmas tree.

[0011] In some embodiments, at least one of a control system distribution unit, a control module, and a communication module is pre-installed or later-installed downstream of the umbilical cable terminal.

[0012] In some embodiments, the subsea production system includes a power cable terminal installed on the base. The power cable terminal is connected to the Christmas tree through a pre-installed or later-installed jumper cable to supply power to the downhole pumping system connected to the Christmas tree.

[0013] In some embodiments, both ends of the jumper cable are detachably connected; and / or, the jumper cable is pre-installed or later-installed on the base.

[0014] In some embodiments, the support structure on the upper part of the base is composed of round tubes and / or steel sections.

[0015] The beneficial effects of the embodiments of the present invention are as follows: Different from the prior art, a subsea production system provided by the embodiments of the present invention includes devices such as a base, an oil and gas main pipe and a Christmas tree branch pipe, a drilling conductor, and a Christmas tree. The oil and gas main pipe and the Christmas tree branch pipe, and the drilling conductor are arranged on the base; the Christmas tree is detachably installed on a wellhead installed later inside the drilling conductor, and the Christmas tree is communicated with the wellhead, a later-installed crossover pipe, and a pre-installed or later-installed jumper cable. The embodiments of the present invention integrate devices such as the oil and gas main pipe and the Christmas tree branch pipe, the drilling conductor, the Christmas tree, the crossover pipe, and the jumper cable on the base to form an integral whole, and drive the overall sinking and floating of the subsea production system through suction piles, thereby realizing the installation and recovery of the subsea production system, enabling the subsea production system to be reused, and thus reducing the development cost of marginal oilfields. Description of the Drawings

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments of the present invention. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the drawings.

[0017] Figure 1 is a perspective view of the underwater production system provided by the embodiment of the present invention;

[0018] Figure 2 is a top view of the underwater production system provided by the embodiment of the present invention;

[0019] Figure 3 is a side view of the underwater production system provided by the embodiment of the present invention.

[0020] The reference numerals in the specific embodiments are as follows:

[0021] 1. Drilling conductor; 2. Umbilical cable terminal; 3. Suction pile; 4. Main oil and gas pipeline; 5. Power cable terminal; 6. Christmas tree; 7. Single suction pump control manifold; 8. Christmas tree branch pipe; 9. Jumper; 10. Support structure. Specific embodiments

[0022] To facilitate the understanding of the present invention, the following will describe the present invention in more detail in conjunction with the drawings and specific embodiments. It should be noted that when an element is expressed as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is expressed as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this specification are only for the purpose of illustration.

[0023] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in this specification in the description of the present invention are only for the purpose of describing specific embodiments and are not used to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0024] An underwater production system refers to a production system that uses underwater completion technology combined with facilities such as fixed platforms and floating production platforms to form different offshore oilfield development forms, and is one of the key technologies for offshore oilfield development.

[0025] However, during the operation of currently commonly used subsea production systems, most of them are used once, that is, they are fixed for long-term operation after installation and are no longer recovered and relocated. This results in a relatively large investment in fixed assets for the development of an oil and gas field. Therefore, for the development of marginal shallow-water oil and gas fields (generally referring to those oil and gas fields with small reserves in remote areas), if a conventional subsea production system is used for development, due to the very poor economic benefits of marginal oil and gas fields, it will be difficult to obtain good economic benefits. In addition, the current mainstream mode of subsea production systems is the central manifold type (usually also referred to as subsea cluster type, satellite well type), and the equipment of its subsea production system is distributed, requiring a relatively large space for facilities.

[0026] In the embodiment of the present utility model, by integrating equipment such as the oil and gas main pipe, production tree branch pipe, drilling conductor, production tree, jumper pipe, flying wire, etc. into the base to form an integral body, the overall structure of the subsea production system is made compact, and the suction pile is used to drive the sinking and floating of the entire subsea production system, thereby realizing the installation and recovery of the subsea production system, enabling the subsea production system to be reused, and thus reducing the development cost of marginal oil fields.

[0027] To facilitate the reader's understanding of the inventive concept of the present utility model, the specific structure of the subsea production system is described as follows:

[0028] Please refer to Figures 1-3 , the subsea production system includes a base, an oil and gas main pipe 4, a production tree branch pipe 8, a drilling conductor 1, a production tree 6, etc. The base serves as the core support structure of the subsea production system, carrying equipment such as the production tree 6, drilling conductor 1, oil and gas main pipe 4, production tree branch pipe 8 above, and firmly connecting them together to form a compact integrated structure; the drilling conductor 1 is arranged on the base, and the drilling conductor 1 passes through the base to drill the oil field so that the subsequent production tree 6 can extract oil and gas; the production tree 6 is detachably installed on the wellhead installed later inside the drilling conductor 1, and the production tree 6 is connected to the wellhead (not shown in the figure), the jumper pipe installed later, and the flying wire 9 installed in advance or later. Preferably, the installation position of the production tree 6 corresponds to that of the drilling conductor 1. For example, the middle of the bottom of the production tree 6 is sleeved on the drilling conductor 1, and the production tree 6 is used to collect oil and gas from the oil field; the suction pile 3 is located at the lower part of the base, and the suction pile 3 is used to provide a stable basic support for the entire subsea production system. By driving the sinking and floating of the suction pile 3, the sinking and floating of the entire system can be driven, thereby realizing the installation and recovery of the subsea production system, enabling the subsea production system to be reused, and thus reducing the development cost of marginal oil fields.

[0029] For the above-mentioned base, the base is composed of at least two suction piles 3, a floating and sinking control component, and a support structure 10 located above the suction piles 3. The support structure 10 is composed of round tubes and / or steel sections to facilitate the processing and preparation of the upper structure of the base. For example, the support structure 10 includes several steel sections distributed crosswise to form a stable load-bearing frame. The steel sections are fixed and connected through connectors. The connectors can be the cooperation of bolts and nuts. Of course, the steel sections can also be fixed by welding.

[0030] For the above-mentioned Christmas tree 6, the Christmas tree 6 can be composed of a connector and a Christmas tree body. The number of the Christmas trees 6 and the drilling conduits 1 can be two or more. Preferably, two or more drilling conduits 1 are arranged in an array evenly on both sides of the base to make the structure of the subsea production system compact. One Christmas tree 6 communicates with the wellhead installed later inside one drilling conduit 1. Of course, the specific number of the Christmas trees 6 can be adjusted accordingly according to the actual oilfield to be exploited.

[0031] Preferably, the periphery of the bottom of the Christmas tree 6 is detachably installed on the wellhead installed later inside the drilling conduit 1; and / or, the wellhead is provided with a guiding member, and the Christmas tree 6 is matched with the guiding member to position the Christmas tree 6 and the wellhead. The fixing member can be the cooperation of bolts and nuts, a clamp or a flange. For example, the periphery of the bottom of the Christmas tree 6 is provided with first installation holes, and the periphery of the wellhead is provided with second installation holes. The bolts pass through the first installation holes and the second installation holes in sequence and are screwed with nuts to fix the Christmas tree 6 on the wellhead. The guiding member can be a positioning pin, a guiding arm or a sliding track. For example, the wellhead is provided with a positioning pin, and the bottom of the Christmas tree 6 is provided with a guiding hole. When the Christmas tree 6 is installed on the wellhead, the positioning pin is inserted into the positioning hole to position the Christmas tree 6 and the wellhead.

[0032] Furthermore, the subsea production system includes a pre-installed oil and gas main pipe 4 and a pre-installed Christmas tree branch pipe 8. One end of the Christmas tree branch pipe 8 is detachably connected to the Christmas tree 6 through a post-installed crossover pipe. The other end of the Christmas tree branch pipe 8 is fixedly pre-connected to the oil and gas main pipe 4 to converge the oil and gas collected by the Christmas tree 6 to the oil and gas main pipe 4 and then transport it to the outside through the main pipe. Through the detachable connection method of the crossover pipe, the Christmas tree 6 and the Christmas tree branch pipe 8 can be connected or disconnected quickly and safely to adapt to different production requirements and maintenance operations. The detachable connection method can be a flange connection, a claw connection, a clamp connection or a threaded connection, etc.

[0033] Preferably, the main oil and gas pipe 4 and the production tree branch pipe 8 are pre-installed in the upper structure of the base. In this way, when several production trees 6 are installed on the base, the distances between the main oil and gas pipe 4 and each production tree 6 are relatively balanced, which is convenient for connection and wiring layout. Further, the production tree branch pipe 8 is arranged around the production tree 6 to reduce the possibility of the production tree branch pipe 8 occupying the installation area of the production tree 6.

[0034] Preferably, the main oil and gas pipe 4 is detachably connected to the subsea pipeline outside the base to transport the oil and gas converged by the main oil and gas pipe 4 to a place far from the production area, such as an oil and gas processing platform, an onshore oil and gas storage station or the international market. Through the detachable connection, the main oil and gas pipe 4 and the subsea pipeline can be quickly and safely connected or disconnected to meet different production requirements and maintenance operations. For example, the main oil and gas pipe 4 is provided with a male head, and the subsea pipeline or the subsea pipeline jumper is provided with a female head, and the male head of the main oil and gas pipe 4 is detachably connected to the subsea pipeline outside the base. Further, a main pipe valve may be provided on the main oil and gas pipe 4 to open or close the main oil and gas pipe 4 and regulate the flow rate of the main oil and gas pipe 4. A flow meter may also be provided on the main oil and gas pipe 4 to measure the flow rate of the oil and gas in the main oil and gas pipe 4. Equipment such as chemical reagent injection holes, temperature and pressure sensors, and sand production monitors may also be provided on the main oil and gas pipe 4 for chemical reagent injection, temperature and pressure monitoring, and sand production monitoring, etc.

[0035] Preferably, the pipeline of the production tree branch pipe 8 and the production tree 6 is connected by a detachable jumper pipe to collect the oil and gas of the production tree branch pipe 8 into the main oil and gas pipe 4. Through the detachable connection, the production tree branch pipe 8 and the production tree 6 can be quickly and safely connected or disconnected to meet different production requirements and maintenance operations. For example, the production tree branch pipe 8 is provided with a claw male head, and the subsea pipeline or the subsea pipeline jumper is provided with a claw female head, and the male head of the production tree branch pipe 8 is detachably connected to the female head of the jumper pipe. The other end of the jumper pipe is connected to the pipeline claw male head of the production tree 6 in the same principle. Further, a branch pipe valve may be provided on the production tree branch pipe 8 to open or close the production tree branch pipe 8 and regulate the flow rate of the production tree branch pipe 8. A flow meter may also be provided on the production tree branch pipe 8 to measure the flow rate of the oil and gas in the production tree branch pipe 8. Equipment such as chemical reagent injection holes, temperature and pressure sensors, and sand production monitors may also be provided on the production tree branch pipe 8 for chemical reagent injection, temperature and pressure monitoring, and sand production monitoring, etc.

[0036] In some embodiments, the subsea production system includes a umbilical termination 2 installed above the base. The umbilical termination 2 is connected to the Christmas tree 6 and other base equipment through pre-installed or post-installed jumpers 9 to transmit power, communication signals, hydraulic oil, and chemical agents to the Christmas tree 6 and other base equipment. Downstream of the umbilical termination, equipment such as a control system distribution unit, control module, and communication module can be pre-installed or post-installed as needed. Further, the subsea production system includes a power cable termination 5 installed above the base. The power cable termination 5 is connected to the Christmas tree 6 through pre-installed or post-installed jumpers 9 to supply power to the downhole oil pump connected to the Christmas tree 6. Preferably, both the umbilical termination 2 and the power cable termination 5 are installed on the periphery above the base so that more space can be provided in the middle of the base for installing the Christmas tree 6. Of course, the umbilical termination 2 and the power cable termination 5 can also be installed at other positions above the base.

[0037] Preferably, both ends of the jumper 9 are detachably connected. In this way, the jumper 9 can be quickly and safely connected or disconnected to meet different production requirements and maintenance operations. The detachable connection can be the detachable connection of the above-mentioned Christmas tree branch pipe 8. For example, male and female connectors are respectively provided at both ends of the jumper 9, the Christmas tree 6 is provided with a female connector, and the umbilical termination 2 is provided with a male connector. The male connector at one end of the jumper 9 is detachably connected to the female connector of the Christmas tree 6, and the female connector at the other end of the jumper 9 is detachably connected to the male connector of the umbilical termination 2. Further, the jumper 9 is arranged on the periphery of the Christmas tree 6 to reduce the possibility of the jumper 9 occupying the installation area of the Christmas tree 6.

[0038] In some embodiments, the subsea production system includes a fastener. The fastener includes a collar and a suction cup connected to each other. The collar is circular in shape, and a receiving space is formed by enclosing the inner wall of the collar. The collar is provided with a gap through which the jumper 9 can enter the receiving space of the collar. The suction cup is connected to the outer wall of the collar and is used to adsorb on the base. During use, the fastener first inserts several jumpers 9 into the receiving space through the gap, and then adsorbs on the base through the suction cup, thereby fixing several jumpers 9 at any position on the base. When the fastener needs to be detached from the base, the user only needs to apply a pulling force on the fastener towards the outside of the base, and the suction cup of the fastener can be detached from the base. In this way, the jumper 9 can be flexibly adjusted and installed at a position on the base through the fastener.

[0039] Further, the above-mentioned sinking and floating control assembly includes a single suction pump control manifold 7 and a suction pile pipeline installed on the base. One end of the single suction pump control manifold 7 is provided with a suction pile pipeline connection port. The number of the suction pile pipeline connection ports is the same as the number of the suction piles 3. The suction pile pipeline connection ports are connected to the inside of the suction piles 3 through pre-installed suction pile pipelines. The other end of the single suction pump control manifold 7 is used to be connected to a single suction pump during underwater installation or recovery. The single suction pump is used to suck or discharge media into the suction piles 3, so as to form a pressure difference between the internal space of the suction piles 3 and the outside, thereby causing the suction piles 3 to sink or float, and thus driving the underwater production system to sink or float.

[0040] Preferably, the number of the suction piles 3 and the suction pile pipelines is two or more. Two or more suction piles 3 are evenly distributed around the periphery of the base to stably drive the underwater production system to sink or float. Among them, the number of the suction piles 3 is preferably two, three or four. Of course, the number of the suction piles 3 can also be more than four. One end of the single suction pump control manifold 7 is provided with two or more suction pile pipeline connection ports. One suction pile 3 is connected to one suction pile pipeline connection port through one suction pile pipeline. The other end of the single suction pump control manifold 7 is provided with a single suction pump connection port, and the single suction pump connection port is used to be connected to a single suction pump. In this way, the underwater production system of the present application only needs one single suction pump to realize the suction (sinking) or discharge (floating) work of all the suction piles 3.

[0041] Further, a pipeline valve is pre-installed on each suction pile pipeline. The pipeline valve is used to control the closing and opening of the suction pile pipeline and the flow rate of the suction pile pipeline. By adjusting the pipeline valves corresponding to each suction pile pipeline, the internal and external pressure differences of each suction pile 3 can be better controlled to be the same, so as to better adjust the levelness of the underwater production system. Further, a depth mark is arranged on the outer side of the suction pile 3, and the depth mark is used to monitor the sinking depth of the suction pile 3; a horizontal marking instrument is arranged on the top of the suction pile 3, and the horizontal marking instrument is used to monitor the horizontal inclination angle of one suction pile 3; among them, the horizontal detection device can be a bull's eye, a compass, a level (such as a bubble level, an electronic level, a magnetic level and a laser level) or a gyrotheodolite.

[0042] In some embodiments, two adjacent suction piles 3 can be connected through a connecting piece to improve the stability between the suction piles 3. The connecting piece can be a connecting rod, a metal pipe or a cover plate.

[0043] In some embodiments, the suction pump connection port is provided with a switch structure (not shown in the figure), and the switch structure is used to open and close the suction pump connection port. The switch structure can be a valve, a piston or a cover piece.

[0044] In some embodiments, the subsea production system further includes two or more sealing rings (not shown in the figure). One of the sealing rings surrounds the connection between the pipeline and the single suction pump control manifold 7 to enhance the sealing performance at the connection between the pipeline and the single suction pump control manifold 7.

[0045] In some embodiments, the subsea production system includes an airbag (not shown in the figure). The airbag surrounds and adheres to the side wall below the suction pile 3. The airbag is provided with an air inlet and an air outlet. A one-way valve is provided at the air inlet, and external gas can enter the airbag through the one-way valve. The one-way valve is connected to an air pump through a trachea, and the air pump is used to inflate the airbag; a sealing cover is provided at the air outlet, and the sealing cover is used to seal the air outlet; when the subsea production system floats, the user can inflate the airbag through the air pump, thereby increasing the buoyancy of the suction pile 3 to make the suction pile 3 float faster; when the airbag needs to leak air, the user can remove the sealing cover at the air outlet so that the gas in the airbag can be discharged from the air outlet.

[0046] For the convenience of readers to understand the inventive concept of the present utility model, the working process of the subsea production system is described as follows:

[0047] First, a base is fabricated, which includes multiple suction piles 3, a floating and sinking control component, and a support structure 10 located above the suction piles 3. Before the underwater production system is launched into the water, pre-installation needs to be carried out first, that is, underwater production system equipment such as the main oil and gas pipeline 4, the production tree branch pipe 8, the drilling conductor 1, and the flying wire 9 (which can also be installed later) are installed on the base to form a preliminary overall structure of the underwater production system; then the preliminary overall structure of the pre-installed underwater production system is launched into the water for installation, allowing it to automatically sink under the action of its own gravity; then a single suction pump is connected to the single suction pump connection port of the single suction pump control manifold 7, and the medium in the internal space of each suction pile 3 is pumped out through the single suction pump, so as to form a pressure difference between the outside and the inside of each suction pile 3, and under the action of the pressure difference, the preliminary overall structure of the underwater production system continues to sink; during the process of the preliminary overall structure of the underwater production system continuing to sink, adjust the pipeline valves of the suction pile pipelines so that the horizontal inclination angles of each suction pile 3 are all within the preset error range. When the sinking depth of the preliminary overall structure of the underwater production system reaches the preset depth and the horizontal inclination angles of each suction pile 3 are all within the preset error range, the installation and sinking of the preliminary overall structure of the underwater production system are completed; recover the single suction pump. After the sinking is completed, drill the oilfield through the drilling conductor 1; after the drilling is completed, install the production tree 6 on the wellhead installed later inside the drilling conductor 1 through a hoisting device, and then connect and fix the production tree branch pipe 8 and the flying wire 9 through an underwater robot (ROV) or a diver to form a complete overall structure of the underwater production system. Then connect the umbilical cable outside the base; if necessary, connect the power cable. Connect the main oil and gas pipeline 4 to the offshore pipeline outside the base. In this way, the underwater production system can carry out oil production work. When the underwater production system finishes working and needs to be recovered, disconnect the production tree 6 from the wellhead, the production tree branch pipe 8, and the flying wire 9, and remove the production tree 6 from the base through a hoisting device. Disconnect the connection between the base and the offshore pipeline, umbilical cable, and power cable (if any) outside the base. Then install the single suction pump, reverse the working direction of the single suction pump, so as to discharge the external medium into the internal space of each suction pile 3, so as to form a pressure difference between the outside and the inside of each suction pile 3, and under the action of the pressure difference, the underwater production system floats up, adjust the pipeline valves of the suction pile pipelines so that the horizontal inclination angles of each suction pile 3 are all within the preset error range, thereby recovering and floating up the underwater production system.

[0048] In the embodiment of the present utility model, the underwater production system integrates devices such as the main oil and gas pipe 4, the production tree branch pipe 8, the drilling conductor 1, and the production tree 6 on the base to form an integral whole, and drives the sinking and floating of the whole system through the suction pile 3, so as to realize the installation and recovery of the underwater production system, enabling the underwater production system to be reused, thereby reducing the development cost of marginal oil fields. In addition, by integrating the drilling conductor 1, the main oil and gas pipe 4, the production tree branch pipe 8, the umbilical cable terminal 2, the power cable terminal 5, the flying wire 9, the suction pile 3, and the single suction pump control manifold 7 on the base, the underwater production system has a compact structure. In addition, all the suction piles 3 are only pumped or discharged through a single suction pump. By adjusting the pipeline valves corresponding to each suction pile 3, the internal and external pressure differences of each suction pile 3 can be better controlled to be the same, so as to better adjust the levelness of the underwater production system. During the installation and recovery of the underwater production system, only a single suction pump is required for operation, which not only maintains the pressure balance between the suction piles 3, saves costs, but also reduces the number of suction pumps required, making it more portable for transportation. In addition, for the installation and recovery of the suction pumps in the prior art, since multiple suction pumps are used, multiple underwater robots, divers, or auxiliary tools are required for installation and monitoring. However, only one underwater robot, diver, or auxiliary tool is required for the installation of the single suction pump of the present application, saving costs.

[0049] It should be noted that the description and drawings of the present utility model give preferred embodiments of the present utility model. However, the present utility model can be implemented in many different forms and is not limited to the embodiments described in this specification. These embodiments do not serve as additional limitations to the content of the present utility model. The purpose of providing these embodiments is to make the understanding of the disclosed content of the present utility model more thorough and comprehensive. Moreover, the above-mentioned technical features continue to be combined with each other to form various embodiments not listed above, which are all regarded as within the scope described in the description of the present utility model. Further, for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of the present utility model.

Claims

1. A subsea production system, characterized in that: include: A base, the base consisting of at least two suction piles, a sinking and buoyancy control assembly, and a supporting structure located above the suction piles; A drilling guide tube, preset on the base; A Christmas tree, a wellhead installed detachably and post-installed inside the drilling conduit, the Christmas tree being connected to the wellhead and the post-installed jumper pipe and the pre-installed or post-installed flying line.

2. The underwater production system according to claim 1, characterized in that: The underwater production system includes a pre-installed oil and gas main pipe and a pre-installed Christmas tree branch pipe, one end of the Christmas tree branch pipe is connected to the Christmas tree through a detachable post-installed jumper pipe, and the other end of the Christmas tree branch pipe is connected to the pre-installed oil and gas main pipe; the oil and gas main pipe and the Christmas tree branch pipe are pre-installed with at least one of a valve, a flow meter, a chemical reagent injection hole, a temperature and pressure sensor, and a sand production monitor.

3. The underwater production system according to claim 2, characterized in that: The pre-installed oil and gas main pipe is connected to the sea pipe outside the base in a detachable manner.

4. The underwater production system according to claim 1, characterized in that: The sinking and buoyancy control assembly includes a single suction pump control manifold and a suction pile pipeline pre-installed on the base. A suction pile pipeline connection port is opened at one end of the single suction pump control manifold. The number of the suction pile pipeline connection ports is the same as the number of the suction piles. The suction pile pipeline connection port is connected to the suction pile through the pre-installed suction pile pipeline. The other end of the single suction pump control manifold is used for connecting with a single suction pump during underwater installation or recovery.

5. The underwater production system according to claim 4, characterized in that: A pipeline valve is pre-installed on the suction pile pipeline, and the pipeline valve is used to control the closing and opening of the suction pile pipeline and the flow rate of the suction pile pipeline.

6. The underwater production system according to claim 1, characterized in that: The subsea production system comprises an umbilical cable terminal installed on the base, and the umbilical cable terminal is connected to the Christmas tree through a pre-installed or post-installed flying line to transmit power, communication signals, hydraulic oil and chemicals to the Christmas tree.

7. The underwater production system according to claim 6, characterized in that: At least one of a control system distribution unit, a control module and a communication module is pre-installed or post-installed downstream of the umbilical cable terminal.

8. The underwater production system according to claim 1, characterized in that: The subsea production system comprises a power cable terminal installed on the base, and the power cable terminal is connected to the Christmas tree through a pre-installed or post-installed flying line to supply power to a downhole oil pumping system connected to the Christmas tree.

9. The underwater production system according to claim 7 or 8, characterized in that: Both ends of the flying wire are connected in a detachable manner; and / or the flying wire is pre-installed or post-installed on the base.

10. The underwater production system according to any one of claims 1 to 8, characterized in that: The supporting structure on the upper part of the base is composed of round tubes and / or steel sections.

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