Suction pile type multi-wellhead base plate suitable for deepwater shallow soft stratum

Abstract

The invention discloses a suction pile type multi-wellhead base plate suitable for a deep water shallow soft stratum. The suction pile type multi-wellhead base plate comprises a truss structure, at least two suction piles, at least two center pipes and at least two spraying devices. The truss structure is connected to the tops of the at least two suction piles; the central pipe is inserted into the suction pile and is used for guiding in a guide pipe; the spraying device comprises a water sprayer and a porous water pipe which are connected; the water sprayer is arranged on the side, close to the center of the truss structure, of the top of the suction pile. The porous water pipes are distributed on the outer side walls of the suction piles; according to the suction pile type multi-wellhead base plate, two or two suction piles are combined to serve as the wellhead base plate, so that the bearing capacity of the wellheads is improved, dangers such as sinking of the wellheads are effectively prevented, the space in the suction piles is effectively utilized, the problem that the number of wellhead grooves is limited is solved, the cost of drilling engineering is reduced, and economic benefits are improved; and by arranging the spraying device, soil blockage between two or more suction piles is effectively prevented.

Description

Technical Field

[0001] The invention relates to the technical field of marine drilling and production operations, and in particular to a suction pile type multi-wellhead base plate suitable for deep-water shallow soft formations. Background Art

[0002] In deepwater drilling projects, the requirements for wellhead stability are very high, and maintaining wellhead stability is the primary condition for continuous drilling, successful drilling and reducing complex situations downhole.

[0003] At present, for deepwater drilling projects, the bearing capacity of the casing is usually adjusted by adjusting the depth of the casing entering the mud. However, in drilling projects in deepwater shallow soft formations, since the formation has not yet been lithified, the cementation is loose and it is easy to collapse, in order to ensure that the shallow target point can be drilled, the depth of the inclination point of the wellbore trajectory will be shallow. At the same time, the depth of the casing entering the mud will also be reduced accordingly, and the contact area between the casing and the formation will be reduced. At this time, the bearing capacity of the wellhead will be insufficient. In the later stage, when a large blowout preventer sits on the wellhead, the risk of wellhead sinking will increase, causing complex conditions underground and increasing the difficulty of on-site processing.

[0004] In deepwater oil and gas exploration and development operations, base plate manifolds and cluster manifolds are the two main forms of drilling wellhead layout. Among them, the cluster manifold is directly connected to the manifold by setting jumper pipes, while the base plate manifold has several wellhead slots inside the structure, and the water-insulating pipes are lowered from the inside of the wellhead slots. When the output of the oil and gas field is large, a considerable number of wellhead slots are required, which will increase the number of jumper pipes or the size of the base plate manifold, thereby significantly increasing the construction and installation costs. Summary of the invention

[0005] In order to enrich the types of wellhead devices in deepwater formations and increase the selection space for wellhead setting methods in marine oil and gas projects, the present invention proposes a suction pile type multi-wellhead base suitable for deepwater shallow soft formations.

[0006] The embodiment of the present invention provides a suction pile type multi-wellhead template suitable for deep water shallow soft formations, comprising a truss structure, at least two suction piles, at least two central pipes and at least two jet flushing devices;

[0007] The truss structure is connected to the top of the at least two suction piles;

[0008] The central tube is inserted into the suction pile and is used to introduce the catheter;

[0009] The spraying device includes a connected sprinkler and a porous water pipe; the sprinkler is arranged on one side of the top of the suction pile close to the center of the truss structure; the porous water pipe is arranged on the outer side wall of the suction pile.

[0010] In one or some optional embodiments, a centralizer is provided on the inner wall of the central tube;

[0011] The centralizer is semi-cylindrical, and has sloped transition sections at both ends;

[0012] The centralizers are evenly arranged along the circumference of the inner wall of the central tube.

[0013] In one or some optional embodiments, the suction pile type multi-wellhead template suitable for deep water shallow soft formations further includes a connecting plate;

[0014] The connecting plate is disposed at the lower part of the at least two suction piles to connect the at least two suction piles.

[0015] In one or some optional embodiments, the number of the central tubes corresponds to the number of the suction piles, and each of the suction piles is inserted with one central tube.

[0016] In one or some optional embodiments, each of the suction piles is provided with at least one of the jetting devices.

[0017] In one or some optional embodiments, a trumpet-shaped expansion portion is provided at the top of the central tube.

[0018] In one or some optional embodiments, a first reinforcement structure is provided around the flared portion;

[0019] The first reinforcement structure is fixed to the suction pile.

[0020] In one or some optional embodiments, a second reinforcement structure is further provided on the top of each suction pile.

[0021] In one or some optional embodiments, a drainage outlet is provided at the top of each suction pile;

[0022] The drain port is suitable for connecting to a suction pump.

[0023] In one or some optional embodiments, the suction pile type multi-wellhead template suitable for deep water and shallow soft formations also includes a leveling device arranged on the top of the suction pile.

[0024] In one or some optional embodiments, the suction pile type multi-wellhead template suitable for deep water and shallow soft formations also includes a pressure monitoring device arranged on the top of the suction pile.

[0025] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0026] The suction pile type multi-wellhead base suitable for deep-water shallow soft formations provided in the embodiment of the present invention connects two or more suction piles through a truss structure, and a central pipe for introducing a catheter is arranged in the suction pile. Two or more suction piles are combined as a wellhead base, which not only improves the bearing capacity of the wellhead and effectively prevents the occurrence of dangers such as wellhead sinking, but also effectively utilizes the space in the suction pile, solves the problem of limited number of wellhead slots, reduces the cost of drilling projects, and improves economic benefits; the truss structure combines multiple suction piles together, so that the suction pile type multi-wellhead base has good overall strength and rigidity, and improves safety during installation; by arranging a spraying device, water is sprayed outward from the outer wall of the suction pile, which effectively prevents soil plugging between two or more suction piles, so that the two or more connected suction piles can penetrate the formation smoothly.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0028] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 A schematic diagram of the structure of a suction pile type multi-wellhead template suitable for deep water and shallow soft formations provided in an embodiment of the present invention;

[0031] Figure 2 A top view of a suction pile type multi-wellhead template suitable for deep water and shallow soft formations provided in an embodiment of the present invention;

[0032] Figure 3 It is a schematic structural diagram of a single suction pile provided in an embodiment of the present invention;

[0033] Figure 4 Provided in the embodiments of the present invention Figure 3 AA section view;

[0034] Figure 5 A schematic diagram of the distribution of the centralizer provided in an embodiment of the present invention;

[0035] Figure 6 It is a schematic diagram of the structure of the centralizer provided in an embodiment of the present invention.

[0036] In the figure:

[0037] 1 is a suction pile, 101 is a top plate, 102 is a pile body, 2 is a central tube, 3 is a truss structure, 4 is a jetting device, 41 is a sprinkler, 42 is a porous water pipe, 5 is a centralizer, 6 is a connecting plate, 7 is a drain port, 8 is a flaring portion, 9 is a first reinforcement structure, 10 is a second reinforcement structure, 11 is an ROV interface, 12 is a leveling device, 13 is a monitoring device, and 14 is a hanging point;

[0038] 100 is a catheter. DETAILED DESCRIPTION

[0039] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The inventors found that in the offshore natural gas hydrate trial production project, it is difficult to achieve horizontal well drilling in such shallow soft formations because the formation has not yet formed rock, the cementation is loose and it is easy to collapse. The main difficulties are as follows: First, the reservoir is shallow and the slope requirement is too large; second, the depth of conventional catheters in shallow soft formations is limited. Under this limitation, if the catheter length is insufficient and cannot provide sufficient bearing capacity, serious consequences such as wellhead sinking and instability will occur. If the catheter is lowered to a sufficient depth to meet the wellhead stability requirements, the construction and installation costs of the project will increase significantly. In deepwater drilling projects, in order to control the construction and installation costs of the project, the number of wellhead slots is often limited, which to a certain extent restricts the scale of oil and gas production.

[0043] Patent application number CN115492555A discloses a "single-tube multi-well suction pile wellhead device", which improves the bearing capacity of the wellhead by dividing the suction pile into compartments and inserting a central pipe into each compartment. However, in this device, a single suction pile needs to accommodate multiple central pipes, and the bearing capacity that the suction pile can provide is limited, and the scope of application is small. When used in deep-water shallow soft formations with a high degree of cementation and looseness, there is a risk of wellhead sinking and instability.

[0044] Based on this, an embodiment of the present invention provides a suction pile type multi-wellhead base suitable for deep water shallow soft formations, which is described in detail below through specific embodiments.

[0045] Example

[0046] The embodiment of the present invention provides a suction pile type multi-wellhead base plate suitable for deep water shallow soft formations, referring to Figure 1-Figure 4 As shown, it includes a truss structure 3, at least two suction piles 1, at least two central pipes 2 and at least two jetting devices 4;

[0047] The truss structure 3 is connected to the top of at least two suction piles 1;

[0048] The central tube 2 is inserted into the suction pile 1 and is used to introduce the catheter 100;

[0049] The spraying device 4 includes a connected water sprinkler 41 and a porous water pipe 42 ; the water sprinkler 41 is arranged on one side of the top of the suction pile 1 close to the center of the truss structure 3 ; the porous water pipe 42 is arranged on the outer side wall of the suction pile 1 .

[0050] The suction pile type multi-wellhead base plate (hereinafter referred to as the multi-wellhead base plate) provided by the embodiment of the present invention is suitable for deep-water shallow soft formations and can be used for marine oil and gas and hydrate exploitation. Its main application methods include: after the multi-wellhead base plate is built on land, it is loaded on a ship and transported to the installation sea area, and then the multi-wellhead base plate is hoisted to the seabed by an engineering ship; the multi-wellhead base plate is penetrated to a preset mud penetration depth under the action of its own weight and suction, completing the preparation work before drilling. After the multi-wellhead base plate is lowered into the formation and stably placed, the guide tube 100 can be lowered from the central pipe 2 to carry out marine oil and gas and hydrate exploitation.

[0051] In a specific embodiment, the number of suction piles 1 is at least two, which can be reasonably set according to the characteristics of deep-water shallow soft formations. For example, if the formation is highly bonded and loose, as many suction piles 1 as possible are set to improve the bearing capacity of the wellhead device. In the embodiment of the present invention, in order to improve the stability of the wellhead device as much as possible, refer to Figure 1 and Figure 2 As shown, three suction piles 1 are provided, and the three suction piles 1 are connected to each other through a truss structure 3 to form a stable equilateral triangle. The three suction piles 1 are respectively provided at the three endpoints of the equilateral triangle, so that the bearing capacity of the wellhead base is large enough and the stability is better. Each suction pile 1 can also serve as a wellhead base while improving the bearing capacity, increasing the number of wellhead slots, thereby saving drilling costs and indirectly increasing the single well production.

[0052] In the embodiment of the present invention, refer to Figure 1-Figure 3 As shown, the suction pile 1 is a barrel-shaped structure with a capped top, including a pile body 102 and an upper top plate 101. The diameter of the top plate 101 can be 5m-8m, the height of the pile body 102 can be 12m-16m, the spacing between the three suction piles 1 can be 12m-18m, and the weight of a single suction pile 1 can be set between 100 tons and 130 tons, so that the overall structure of the multi-wellhead base is more compact and coordinated. Obviously, the diameter of the top plate 101, the height of the pile body 102, the spacing between the three suction piles 1, and the weight of a single suction pile 1 are not limited to the above-mentioned setting mode, and can be reasonably set according to actual needs, and no limitation is made here. After the suction pile 1 is penetrated into the formation, most of the pile body 102 is placed in the formation. For example, when the height of the pile body 102 is 12m, the lower 11m of the pile body 102 is placed in the formation, and the upper 1m and the top plate 101 are located above the formation, so that the suction pile 1 can also serve as a wellhead device.

[0053] In a specific embodiment, the truss structure 3 can be connected by square steel. On the one hand, the suction piles 1 can be firmly connected to enhance the overall strength and rigidity of the multi-wellhead base plate, so that the multi-wellhead base plate can maintain integrity and stability during transportation, hoisting and other construction processes; on the other hand, it can be used as a wellhead equipment support platform for placing wellhead equipment such as booster devices and metering devices. Compared with a single suction pile wellhead device, the multi-wellhead base plate provided in this embodiment not only has a greater bearing capacity, but also does not require a special wellhead equipment placement platform to be set up next to the suction pile 1, which improves the stability and space utilization of the wellhead device, can save engineering costs, and has good economic benefits.

[0054] According to soil mechanics and pile foundation theory, the vertical bearing capacity of the pile foundation is determined by the friction resistance of the seabed soil around the penetration depth to the side wall of the pile foundation and the supporting force of the soil at the bottom of the pile foundation. Therefore, the larger the contact area between the pile foundation and the soil, the greater the bearing capacity it provides. Based on this, the multi-wellhead base provided by the embodiment of the present invention combines the suction foundation technology with the drilling catheter technology, combines multiple suction piles 1 with large diameters, and at the same time, the suction piles 1 also serve as the wellhead base. A central pipe 2 is set in each suction pile 1. The inner and outer walls of each suction pile 1 and each central pipe 2 are in contact with the soil in the formation, thereby generating a large side friction resistance, so that the multi-wellhead base can provide a large bearing capacity. The central pipe 2 is used to introduce the catheter 100. Since the multi-wellhead base can provide a large bearing capacity, the catheter 100 can be pre-inclined in advance during the process of introducing it into the deep-water shallow soft formation, so as to achieve early inclination and early orientation, leaving a certain amount of space surplus for the lower well section.

[0055] In a specific embodiment, the number of center tubes 2 corresponds to the number of suction piles 1. A center tube 2 is inserted in the center of each suction pile 1, and the center tube 2 serves as a channel for introducing the catheter 100. The suction pile 1 provides bearing capacity for the wellhead, ensuring the lateral stability and longitudinal stability of the wellhead device. Compared with inserting multiple catheters into a single suction pile, a center tube 2 is provided corresponding to each suction pile 1, which can better ensure the stability of the wellhead device after the catheter 100 is introduced. Furthermore, the bearing capacity that a single suction pile can provide is limited, and it cannot be applied to shallow soft formations with a high degree of loose cementation. By fixing two or more suction piles 1 together through a truss structure 3, the resulting multi-wellhead base can provide greater bearing capacity, a wider range of application, and higher stability. In this embodiment, referring to Figure 1 and Figure 2 As shown, the number of the central tubes 2 corresponds to the number of the suction piles 1 , and three central tubes 2 are provided and inserted in the centers of the three suction piles 1 , respectively.

[0056] In a specific embodiment, referring to Figure 3 , Figure 5 and Figure 6As shown, the inner wall of the central tube 2 is provided with a centralizer 5 for centralizing the catheter 100. During the lowering process of the catheter 100, the catheter 100 may tilt, affecting the verticality of the tube body; if the error caused by the tilt accumulates during the lowering process of the catheter 100, it will cause a large deviation in the lowering direction of the catheter 100, causing the catheter 100 to be subjected to a certain bending moment, and even hindering the lowering of the catheter 100 in severe cases. Therefore, it is necessary to provide a centralizer 5 to prevent the catheter 100 from tilting. The centralizer 5 is evenly arranged along the inner wall of the central tube 2, and can limit the lowering direction of the conduit 100 when the conduit 100 enters the central tube 2, so as to ensure the verticality of the conduit 100; the centralizer 5 is semi-cylindrical, and soil will accumulate in the central tube 2 when the suction pile 1 is lowered into the formation. Compared with the prismatic centralizer 5, the centralizer 5 is set to be semi-cylindrical, which can prevent soil from accumulating between it and the wall of the central tube 2, and avoid soil plugging in the central tube 2, thereby ensuring that the conduit 100 can be smoothly lowered vertically; each centralizer 5 is provided with a slope-shaped transition section at both ends, and the slope of the transition section is relatively gentle, so that when the conduit 100 passes through the transition section, it can naturally slide between the centralizers 5, and the conduit 100 will not be hindered by the presence of the centralizer 5. Obviously, when the conduit 100 is lowered, the lowering speed should be kept as slow as possible to avoid collision and deformation.

[0057] In a specific embodiment, the material of the centralizer 5 can be semi-round steel, which has the characteristics of wear resistance and corrosion resistance, and can improve the strength and service life of the centralizer 5. The number of centralizers 5 can be reasonably set according to the inner diameter of the central tube 2 and the outer diameter of the guide tube 100, as long as the guide tube 100 can be guided. For example, a group of centralizers 5 arranged around the inner wall of the central tube 2 is 6, and two or more groups of centralizers 5 can be set at different heights of the central tube 2 according to actual needs.

[0058] The inventor discovered in the process of implementing the present invention that connecting three suction piles 1 into an integral structure of a multi-wellhead base can greatly improve the wellhead bearing capacity. However, in the process of penetrating the multi-wellhead base into the formation, as the depth of penetration increases, there is no relative displacement between the soil between the piles and the suction piles 1, and soil will gradually accumulate between the three suction piles 1. When the soil accumulates to a certain extent, soil plugging will occur between the suction piles 1, resulting in an increase in the penetration resistance of the multi-wellhead base, thereby hindering the penetration of the multi-wellhead base. In order to solve the problem of soil plugging between the three suction piles 1, the present invention proposes to set a spraying device 4 on the suction pile 1, and use hydraulic spraying to flush the soil between the three suction piles 1, so that the soil between the piles is separated from the suction piles 1, and fundamentally prevent soil plugging between the piles.

[0059] In a specific embodiment, a suction pile 1 needs to be provided with at least one spraying device 4. The specific number of the spraying devices 4 can be reasonably set according to the characteristics of the stratum soil and the diameter of the suction pile 1. For example, when the diameter of the suction pile 1 is large and the adhesion of the soil in the stratum is high, two or three spraying devices 4 can be set to ensure that the force of the hydraulic spraying is sufficient to flush the soil between the piles.

[0060] In a specific embodiment, referring to Figure 1 and Figure 2 As shown, the spraying device 4 includes a water sprinkler 41 and a porous water pipe 42; the water sprinkler 41 can spray water after pressurizing it; the porous water pipe 42 is arranged along the height direction of the inner wall of the suction pile 1, and its holes are evenly distributed in the vertical direction and face the space between the three suction piles 1. One end of the porous water pipe 42 is connected to the water sprinkler 41, and the water sprinkler 41 sprays the pressurized water into the porous water pipe 42, and the water can be sprayed out from the holes of the porous water pipe 42 to flush the soil accumulated between the piles.

[0061] In a specific embodiment, in order to improve the stability of the multi-wellhead template, refer to Figure 1 As shown, a connecting plate 6 is provided at the bottom of the three suction piles 1. The connecting plate 6 connects the three suction piles 1 in pairs, and cooperates with the upper truss structure 3 to firmly connect the three suction piles 1 together, further improving the rigidity and strength of the multi-wellhead base plate, so that the multi-wellhead base plate maintains integrity and stability during transportation, hoisting and other construction processes, and enables the displacement of each suction pile 1 to be coordinated and uniformly inserted during the penetration process.

[0062] In the embodiment of the present invention, refer to Figure 2 As shown, a drain port 7 is provided at the top of each suction pile 1, and the drain port 7 can be connected to a suction pump. A switch valve is provided inside the suction pump to realize the opening and closing of the drain port 7; the pressure difference between the inside and outside of the suction pile 1 can be controlled by the suction pump to achieve the purpose of adjusting the structural installation error and realizing a high-precision installation. The specific operation process may include: the drain port 7 is opened to allow the multi-wellhead base plate to sink under its own gravity, and after the multi-wellhead base plate cannot sink under its own gravity, the suction pump is started to suck out the seawater in the suction pile 1, so that the multi-wellhead base plate continues to sink under the suction until the preset mud entry depth is reached, and then the suction is stopped.

[0063] In a specific embodiment, referring to Figure 1 and Figure 3As shown, a trumpet-shaped expansion part 8 is provided at the top of the central tube 2 to enlarge the entrance of the central tube 2, so as to facilitate positioning when the guide tube 100 is lowered, and to provide support for the wellhead. The upper part of the wellhead is connected with high and low pressure wellheads and Christmas trees and other equipment. Since the expansion part 8 needs to provide support force, a first reinforcement structure 9 is provided around the bottom of the expansion part 8 to increase the strength and rigidity of the expansion part 8 and prevent the expansion part 8 from deformation and damage.

[0064] In a specific embodiment, referring to Figure 3 As shown, since the upper part of the wellhead is connected to equipment such as high and low pressure wellheads and Christmas trees, the suction pile 1 needs to provide support force. A second reinforcement structure 10 is arranged under the top plate 101 of each suction pile 1 to increase the strength and rigidity of the top of the suction pile 1 to prevent the suction pile 1 from deformation and damage.

[0065] In a specific embodiment, referring to Figure 2 As shown, each suction pile 1 is also provided with an ROV interface 11, a leveling device 12, a monitoring device 13 and a hanging point 14 at the top. The ROV is connected to the suction pile 1 through the ROV interface 11, so as to realize the related control operations such as the switch and pressure adjustment of the suction pump. The leveling device 12 (such as a bull's eye) can measure the horizontality of the suction pile 1, so that the horizontality can be adjusted in time according to the monitoring results of the leveling device 12 during the penetration of the multi-wellhead base plate into the formation, thereby ensuring the horizontal placement of the multi-wellhead device. The monitoring device 13 is used to monitor the pressure difference in the pile, and adjust the pressure of each suction pump connected to each suction pile 1 according to the monitored pressure difference. The hanging points 14 are respectively set at the boundaries of the top of each suction pile 1.

[0066] The installation process of the multi-wellhead base plate may include: after each suction pile 1 reaches the seabed, it first penetrates into the seabed to a certain depth under the action of its own weight; the suction pump on the top of the suction pile 1 is started to control the internal and external pressure difference of each suction pile 1 respectively, so that the suction pile 1 continues to slowly penetrate into the soil; during the penetration process, the pressure difference displayed by the monitoring device 13 is monitored at any time, and the horizontality of the central pipe 2 is judged and adjusted according to the monitoring results of the leveling device 12; when necessary, the multi-wellhead base plate is leveled by adjusting the internal pressure of the suction pile 1, so as to achieve higher installation accuracy and meet the wellhead horizontality requirements.

[0067] The suction pile type multi-wellhead base suitable for deep-water shallow soft formations provided in the embodiment of the present invention combines two or more suction piles 1 together through a truss structure 3, thereby improving the bearing capacity of the wellhead and effectively preventing the occurrence of dangers such as wellhead sinking; by arranging a central tube 2 for introducing a guide tube 100 in the suction pile 1, the space in the suction pile 1 is effectively utilized, solving the problem of limited number of wellhead slots, reducing the cost of drilling projects, and improving economic benefits; by arranging a jet flushing device 4, soil plugging between the suction piles 1 is effectively avoided, ensuring that the multi-wellhead base can be smoothly lowered into deep-water shallow soft formations; compared with a single suction pile wellhead device, the multi-wellhead base provided in the embodiment of the present invention can provide greater bearing capacity and is applicable to a wider range of deep-water shallow soft formations.

[0068] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A suction pile multi-wellhead base suitable for deep water shallow soft formations, characterized in that: It includes a truss structure, at least two suction piles, at least two central pipes and at least two jetting devices; The truss structure is connected to the top of the at least two suction piles; The central tube is inserted into the suction pile and is used to introduce the catheter; The spraying device includes a connected sprinkler and a porous water pipe; the sprinkler is arranged on one side of the top of the suction pile close to the center of the truss structure; the porous water pipe is arranged on the outer side wall of the suction pile.

2. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: The inner wall of the central tube is provided with a centralizer; The centralizer is semi-cylindrical, and has sloped transition sections at both ends; The centralizers are evenly arranged along the circumference of the inner wall of the central tube.

3. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: Also included is a connection plate; The connecting plate is disposed at the lower part of the at least two suction piles to connect the at least two suction piles.

4. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: The number of the central tubes corresponds to the number of the suction piles, and each of the suction piles is provided with one central tube.

5. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: Each of the suction piles is provided with at least one of the spraying devices.

6. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: The top of the central tube is provided with a bell-shaped expanding portion.

7. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 6 is characterized in that: A first reinforcement structure is arranged around the flared portion; The first reinforcement structure is fixed to the suction pile.

8. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: A second reinforcement structure is also provided on the top of each suction pile.

9. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1 is characterized in that: A drainage outlet is provided on the top of each suction pile; The drain port is suitable for connecting to a suction pump.

10. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1, characterized in that: It also includes a leveling device arranged on the top of the suction pile.

11. The suction pile type multi-wellhead template suitable for deep water shallow soft formation according to claim 1, characterized in that: It also includes a pressure monitoring device arranged on the top of the suction pile.

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