Four-well-slot centralized underwater drilling basal disc and operation mode

Abstract

The four-well-groove centralized underwater drilling base plate comprises a bottom plate, a plurality of underwater wellhead / Christmas tree installation auxiliary devices and an oil / gas conveying pipeline, the underwater wellhead / Christmas tree installation auxiliary devices are distributed on the bottom plate, and the underwater wellhead / Christmas tree installation auxiliary devices are symmetrically distributed on the two sides of the oil / gas conveying pipeline. And a plurality of bridging branch pipes are also arranged on the oil / gas conveying pipeline. After the device is installed in place, the self-elevating drilling platform can complete drilling and completion of four wells and installation operation of an underwater wellhead / Christmas tree at a time, the situation that a traditional distributed wellhead needs frequent pile insertion and extraction and re-in-place operation of the self-elevating drilling platform is avoided, and the field operation efficiency is greatly improved. And the underwater wellhead / Christmas tree is arranged in a centralized manner, so that the standardized installation process is realized, the installation operation difficulty is reduced, and the connection distance and work between the underwater Christmas tree and a submarine oil and gas pipeline are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil drilling equipment, in particular to a four-well slot centralized underwater drilling base plate and an operation method. Background Art

[0002] Marine oil and gas development mostly adopts underwater development mode, in which underwater wellhead and Christmas tree are important equipment.

[0003] Under the existing underwater development model, underwater wellheads and Christmas trees are arranged in a dispersed manner with a long distance between them, which increases the distance and workload of connecting the Christmas trees with the submarine oil and gas pipelines. Moreover, for self-elevating drilling platforms, it is difficult to cover multiple dispersed underwater wellheads and Christmas trees after they are in place at one time, resulting in low operating efficiency.

[0004] Therefore, a four-well slot centralized underwater drilling base is urgently needed. Summary of the invention

[0005] The present invention provides a four-well slot centralized underwater drilling base plate, which solves the problem that traditional decentralized wellheads require frequent pile insertion and extraction and repositioning operations by a self-elevating drilling platform, resulting in low on-site operation efficiency.

[0006] A first aspect of the present invention provides a four-well slot centralized underwater drilling base, comprising a base plate, a plurality of underwater wellhead / Christmas tree installation auxiliary devices and an oil / gas pipeline, wherein a plurality of the underwater wellhead / Christmas tree installation auxiliary devices are distributed on the base plate, and the underwater wellhead / Christmas tree installation auxiliary devices are symmetrically distributed on both sides of the oil / gas pipeline, and the oil / gas pipeline is also provided with a plurality of jumper branches.

[0007] The four-slot centralized underwater drilling template, preferably, the underwater wellhead / Christmas tree installation auxiliary device includes a support, a casing and a guide sleeve, the support is welded to the base plate, and the guide sleeve is provided on the support.

[0008] The four-well slot centralized underwater drilling template preferably has a spacing between the supports at diagonally opposite corners of not less than 2 m, and a spacing between the supports at diagonally opposite corners of not less than 5.5 m.

[0009] The four-well slot centralized underwater drilling template is preferably provided with a flange interface at the top of the jumper pipe for short-circuiting the oil output of the underwater oil production tree, and the two ends of the oil / gas pipeline are connected vertically.

[0010] In the four-well slot centralized underwater drilling template, preferably, the oil / gas pipeline is arranged on the bottom plate through the east-west direction.

[0011] The four-well slot centralized underwater drilling base, preferably, the bottom plate is a hollow structure.

[0012] A second aspect of the present invention provides an operation method of a four-well slot centralized underwater drilling template, including the four-well slot centralized underwater drilling template, and the specific operation method includes the following steps: Lower the bottom plate to the seabed to complete the installation of the bottom plate; Perform drilling installation operations using subsea wellhead / Christmas tree installation auxiliary equipment; The connection is achieved by short-circuiting the oil outlet of the underwater oil production tree through a jumper branch pipe; Carry out perforation, sand control, and completion string lowering to complete the operation; The installation process is repeated in sequence to complete the drilling and completion of all remaining wells and the installation of subsea wellheads / Christmas trees.

[0013] The beneficial effects are: With the jack-up rig in place at one time, multiple wells can be drilled, completed and subsea wellhead / Christmas tree operations can be performed, eliminating the need to relocate the drilling vessel; The support casing can ensure the verticality and height of the water-proof casing (and the upper low-pressure wellhead), ensure the verticality and height of the underwater wellhead / Christmas tree, and facilitate subsequent drilling and completion operations; After the underwater Christmas tree is installed, the oil outlet short circuit and the jumper branch of the oil / gas pipeline are aligned to quickly connect the Christmas tree to the submarine oil / gas pipeline.

[0014] This application avoids the need for frequent pile insertion and repositioning operations of the self-elevating drilling platform in traditional decentralized wellheads, greatly improving on-site operation efficiency. The centralized layout of the underwater wellhead / Christmas tree realizes a standardized installation process, reduces the difficulty of installation operations, and reduces the connection distance and workload between the underwater Christmas tree and the submarine oil and gas pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A top view of a four-well slot centralized underwater drilling template of the present invention; Figure 2 for Figure 1 Side view of Figure 3 for Figure 1 Oblique view of Figure 4 for Figure 1 The support and casing in the In the figure: 1. Bottom plate; 2. First support; 3. Third support; 4. Fourth support; 5. Second support; 6. First casing; 7. Third casing; 8. Fourth casing; 9. Second casing; 10. Oil / gas pipelines; 11. First jumper branch pipe; 12. Third jumper branch pipe; 13. Fourth jumper branch pipe; 14. Second jumper branch pipe; 15. First guide sleeve; 16. Third guide sleeve; 17. Fourth guide sleeve; 18. Fourth guide sleeve; 19. First flange interface; 20. Third flange interface; 21. Fourth flange interface; 22. Second flange interface. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the term "upper" or the like is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the system or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the use of terms such as "first", "second", "third", and "fourth" to define components is only for the convenience of distinguishing the above components. If not otherwise stated, the above terms have no special meaning and cannot be understood as indicating or implying relative importance.

[0018] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" 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 an indirect connection 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.

[0019] The present invention provides a four-well slot centralized underwater drilling base, including a bottom plate, a plurality of underwater wellhead / Christmas tree installation auxiliary devices and an oil / gas pipeline. The bottom plate is provided with a plurality of the underwater wellhead / Christmas tree installation auxiliary devices, and the underwater wellhead / Christmas tree installation auxiliary devices are symmetrically distributed on both sides of the oil / gas pipeline. The oil / gas pipeline is also provided with a plurality of cross-branch pipes. After the present invention is installed in place, the self-elevating drilling platform can complete the drilling and completion of four wells and the installation of the underwater wellhead / Christmas tree at one time, avoiding the need for the self-elevating drilling platform to frequently insert and remove piles and reposition the traditional distributed wellhead, greatly improving the efficiency of on-site operations. In addition, the centralized layout of the underwater wellhead / Christmas tree realizes a standardized installation process, reduces the difficulty of the installation operation, and reduces the connection distance and workload between the underwater Christmas tree and the submarine oil and gas pipeline.

[0020] The entire technical process is described in detail below using a four-well slot centralized underwater drilling template as an example.

[0021] Example 1 like Figures 1 to 4 As shown, a four-well slot centralized underwater drilling base includes a bottom plate 11, a first underwater wellhead / Christmas tree installation auxiliary device, a second underwater wellhead / Christmas tree installation auxiliary device, a third underwater wellhead / Christmas tree installation auxiliary device, a fourth underwater wellhead / Christmas tree installation auxiliary device and an oil / gas pipeline 10. The bottom plate 1 is a steel hollow structure, and the first underwater wellhead / Christmas tree installation auxiliary device, the second underwater wellhead / Christmas tree installation auxiliary device, the third underwater wellhead / Christmas tree installation auxiliary device, the fourth underwater wellhead / Christmas tree installation auxiliary device are distributed on the bottom plate 1. Installation auxiliary devices, and the first underwater wellhead / Christmas tree installation auxiliary device, the second underwater wellhead / Christmas tree installation auxiliary device, the third underwater wellhead / Christmas tree installation auxiliary device, and the fourth underwater wellhead / Christmas tree installation auxiliary device are symmetrically distributed on both sides of the oil / gas pipeline 10. The oil / gas pipeline 10 is also provided with a first jumper branch pipe 11, a third jumper branch pipe 12, a fourth jumper branch pipe 13, and a second jumper branch pipe 14. The oil / gas pipeline 10 is arranged on the bottom plate 1 in the east-west direction and is located at the north-south symmetrical center of the bottom plate 1.

[0022] The oil / gas pipeline 10 is arranged in the east-west direction, which is equivalent to being located in the center of the four-well slot centralized underwater drilling base, so that the oil production trees on the north and south sides can be connected thereto, and after the connection, the two sides of the chassis 1 are evenly stressed.

[0023] Continue to refer to Figure 3As shown, the first underwater wellhead / Christmas tree installation auxiliary device comprises a first support 2, a first casing 6 and a first guide sleeve 15, the first support 2 is welded on the bottom plate 1, and the first guide sleeve 15 is provided on the first support 2; the second underwater wellhead / Christmas tree installation auxiliary device comprises a second support 5, a second casing 9 and a second guide sleeve 18, the second support 5 is welded on the bottom plate 1, and the second support 5 is provided with a second guide sleeve 18; The third underwater wellhead / Christmas tree installation auxiliary device comprises a third support 3, a third casing 7 and a third guide sleeve 16. The third support 3 is welded on the bottom plate 1, and the third guide sleeve 16 is provided on the third support 3. The fourth underwater wellhead / Christmas tree installation auxiliary device comprises a fourth support 4 , a fourth casing 8 and a fourth guide sleeve 17 . The fourth support 4 is welded to the bottom plate 1 , and the fourth guide sleeve 17 is provided on the fourth support 4 .

[0024] The distance between the first support 2 and the fourth support 4 is at least 2m, and the center distance between the first support 2 and the fourth support 4 is at least 5.5m; the distance between the third support 3 and the second support 5 is at least 2m, and the center distance between the third support 3 and the second support 5 is at least 5.5m. The position of each support determines the position of the underwater wellhead / Christmas tree, and the distance is maintained to avoid mutual interference between the underwater wellhead / Christmas tree during the lowering process.

[0025] in, The heights of the four supports, four casings and four guide sleeves are consistent; The casing ensures the centering of the water-proof pipe (and the upper low-pressure wellhead) and limits the height of the water-proof pipe (and the upper low-pressure wellhead); The height of the jumper branch pipe is determined according to the length of the casing and the underwater oil production tree short circuit.

[0026] Continue to refer to Figure 3 As shown, the first jumper branch pipe 11, the third jumper branch pipe 12, the fourth jumper branch pipe 13, and the second jumper branch pipe 14 are respectively reserved with a first flange interface 19, a third flange interface 20, a fourth flange interface 21, and a second flange interface 22 for short-circuiting the oil outlet of the underwater oil production tree, and the two ends of the oil / gas pipeline 10 are vertically connected.

[0027] Example 2 A second aspect of the present invention provides an operation method of a four-well slot centralized underwater drilling template, including the four-well slot centralized underwater drilling template, and the specific operation method includes the following steps: S1: Lower the bottom plate 1 to the seabed to complete the installation of the bottom plate 1.

[0028] Specifically, a four-well slot centralized underwater drilling baseplate is hoisted by an offshore floating crane vessel and slowly lowered to the seabed like water to adjust the horizontality.

[0029] S2: Perform drilling and installation operations using subsea wellhead / Christmas tree installation auxiliary equipment.

[0030] Step S2 specifically includes step S21 and step S22: S21: The drilling ship is located on the south side of the four-well slot centralized underwater drilling base; the cantilever beam is moved and the drilling center is adjusted to be directly above the first support 2.

[0031] S22: After the surface drilling operation is completed, the watertight pipe (and the upper low-pressure wellhead) is lowered, and the first guide sleeve 15 guides the watertight pipe into the first casing 6 until the watertight pipe (and the upper low-pressure wellhead) is lowered to the specified height of the first casing 6, and the pipe string hanging weight is released, and cement is injected into the watertight pipe (and the upper low-pressure wellhead) for cementing. Subsequent drilling and high-pressure wellhead installation operations are continued.

[0032] S3: The connection is achieved by short-circuiting the oil outlet of the underwater oil production tree through a jumper branch pipe.

[0033] The top drive hoists the underwater Christmas tree above the first support 2, slowly lowers it and seats it on the high-pressure wellhead; the diver / ROV confirms that the underwater Christmas tree oil outlet short circuit is properly docked with the first flange interface 19 on the top of the first jumper branch pipe 11, and locks the underwater Christmas tree to the high-pressure wellhead; the diver / ROV completes the connection between the underwater Christmas tree oil outlet short circuit and the first flange interface 19.

[0034] S4: Perform perforation, sand control, and lower the completion string to complete the operation.

[0035] S5: Repeat the installation process in sequence to complete the drilling and completion of the remaining wells and install the subsea wellhead / Christmas tree.

[0036] Specifically, steps S1 to S4 are repeated to complete the drilling and completion of the remaining three wells and the installation of the underwater wellhead / Christmas tree.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A four-well slot centralized underwater drilling template, characterized in that: It comprises a base plate, a plurality of underwater wellhead / Christmas tree installation auxiliary devices and an oil / gas pipeline. The base plate is provided with a plurality of the underwater wellhead / Christmas tree installation auxiliary devices, and the underwater wellhead / Christmas tree installation auxiliary devices are symmetrically distributed on both sides of the oil / gas pipeline. The oil / gas pipeline is also provided with a plurality of jumper branches.

2. The four-well slot centralized underwater drilling template according to claim 1 is characterized in that: The underwater wellhead / Christmas tree installation auxiliary device comprises a support, a casing and a guide sleeve. The support is welded to the bottom plate, and the guide sleeve is arranged on the support.

3. The four-well slot centralized underwater drilling template according to claim 2 is characterized in that: The spacing between the supports at diagonally opposite corners is not less than 2m, and the spacing between the supports at diagonally opposite corners is not less than 5.5m.

4. The four-well slot centralized underwater drilling template according to claim 1 is characterized in that: The top of the jumper branch pipe is reserved with a flange interface for connecting to the oil outlet short circuit of the underwater oil production tree, and both ends of the oil / gas pipeline are connected to a vertical connection interface.

5. The four-well slot centralized underwater drilling template according to any one of claims 1 to 4, characterized in that: The oil / gas pipeline is arranged on the bottom plate through the bottom plate in the east-west direction.

6. The four-well slot centralized underwater drilling template according to any one of claims 1 to 4, characterized in that: The bottom plate is a hollow structure.

7. An operation method of a four-well slot centralized underwater drilling template, characterized in that: The four-well slot centralized underwater drilling template according to any one of claims 1 to 6 is included, and the specific operation method includes the following steps: Lower the bottom plate to the seabed to complete the installation of the bottom plate; Perform drilling installation operations using subsea wellhead / Christmas tree installation auxiliary equipment; The connection is achieved by short-circuiting the oil outlet of the underwater oil production tree through a jumper branch pipe; Carry out perforation, sand control, and completion string lowering to complete the operation; The installation process is repeated in sequence to complete the drilling and completion of all remaining wells and the installation of subsea wellheads / Christmas trees.

Images