Base for underwater blowout preventer group and pressure test operation method

Abstract

The invention relates to an offshore structure, and discloses a base for an underwater blowout preventer group and a pressure test operation method, and the base can comprise a horizontal frame, a vertical frame, a pressure test pile supporting structure and an inclined supporting structure. The horizontal frame and the vertical frames are of a square beam column structure, the bottom edges of the two vertical frames share the same edge with the two opposite edges of the horizontal frame respectively, any vertical frame is perpendicular to the horizontal frame, and the lower blowout preventer or the lower marine riser assembly is installed above the vertical frames. The inclined supporting structure is fixedly connected between the first edge of the vertical frame and the second edge of the horizontal frame, the first edge is adjacent to the second edge, the first edge and the second edge are perpendicular to the common edge, and the pressure test pile supporting structure is fixed to the center of the horizontal frame and used for being connected with a pressure test pile. The pressure test operation method comprises the steps that the base is installed on a deck, and the lower blowout preventer, the lower marine riser assembly and the pressure test pile are connected with the base. Installation and pressure testing work of various devices can be completed through one base.

Description

Technical Field

[0001] The present application relates to offshore structures, and particularly to a base for an underwater blowout preventer stack and a pressure testing operation method. Background Art

[0002] Currently, in the field of offshore oil and gas exploration, underwater blowout preventer stacks are crucial safety equipment, with weights reaching up to 400 tons. Traditionally, an underwater blowout preventer stack consists of a lower riser assembly and a lower blowout preventer. Generally, these two parts are arranged separately and then assembled and pressure tested as a whole in a designated area.

[0003] This traditional arrangement requires the fabrication and installation of various bases. The separate installation of multiple bases occupies a large amount of deck space on the offshore platform. This results in a low utilization rate of the valuable deck area and restricts the layout and operation of other key equipment. Summary of the Invention

[0004] The technical problem to be solved by the present application is: how to improve the deck utilization rate during pressure testing and reduce the on-site alignment and construction volume in a complex environment.

[0005] To solve the above technical problem, the present application provides a base for an underwater blowout preventer stack and a pressure testing operation method.

[0006] In a first aspect of the present application, there is provided a base for an underwater blowout preventer stack, the base comprising: a horizontal frame, the horizontal frame being a square beam-column structure; two vertical frames, the vertical frames being square beam-column structures, the bottom edges of the two vertical frames sharing common sides with two opposite sides of the horizontal frame respectively, and a lower blowout preventer or a lower riser assembly being installed above the vertical frames; an inclined support structure, the inclined support structure being fixedly connected between a first side of the vertical frame and a second side of the horizontal frame, the first side and the second side being adjacent and perpendicular to the bottom edge of the vertical frame respectively; and a test pile support structure, the test pile support structure being fixed at the center of the horizontal frame and used for connecting a test pile.

[0007] In one embodiment, the horizontal frame includes two second horizontal beams parallel to each other and two fourth horizontal beams parallel to each other. The two second horizontal beams and the two fourth horizontal beams form a quadrilateral structure, and the two second horizontal beams are the common sides of the horizontal frame and the vertical frame. The vertical frame includes four first columns, four column lower connecting plates, and two first horizontal beams. The first horizontal beam is parallel to the second horizontal beam. Each column lower connecting plate is fixedly connected to the lower end face of one of the first columns correspondingly. The two first horizontal beams are parallel to each other, and the two first horizontal beams are respectively fixedly connected to the upper ends of the two first columns. The lower ends of the four first columns are respectively fixedly connected to the four corners of the quadrilateral structure. The test pile support structure is at the same height as the horizontal frame. The test pile support structure includes two collinear third horizontal beams, two collinear fifth horizontal beams, a test pile support pipe, and a test pile upper connecting plate. Any one of the third horizontal beams is perpendicular to any one of the fifth horizontal beams. The third horizontal beam is fixed between the test pile support pipe and the second horizontal beam, and the fifth horizontal beam is fixed between the test pile support pipe and the fourth horizontal beam, so that the test pile support pipe is fixed in the middle of the horizontal frame. The test pile upper connecting plate is fixed to the upper part of the test pile support pipe, and the test pile upper connecting plate is used to connect the test pile. The diagonal support structure includes four diagonal support beams. The two ends of any one diagonal support beam are respectively fixedly connected to the adjacent first column and the fourth horizontal beam.

[0008] In one embodiment, the vertical frame further includes at least one second column. The length of the second column is shorter than that of the first column, and the second column is fixedly connected between the first horizontal beam and the second horizontal beam.

[0009] In one embodiment, the horizontal frame further includes a horizontal connecting plate. The fourth horizontal beam is flush with the second horizontal beam in height, and the fourth horizontal beam, the first column, and the second horizontal beam are welded through the horizontal connecting plate.

[0010] In one embodiment, the base further includes a first reinforcing gusset plate. The two right-angle sides of the first reinforcing gusset plate are respectively welded to the fourth horizontal beam and the first column.

[0011] In one embodiment, the test pile support structure further includes a test pile lower connecting plate and a second reinforcing gusset plate. The upper part of the second reinforcing gusset plate is welded to the third horizontal beam or the fifth horizontal beam, the side part of the second reinforcing gusset plate is welded to the test pile support pipe, and the lower part of the second reinforcing gusset plate is welded to the test pile lower connecting plate.

[0012] In one embodiment, the test pile support structure further includes a base backing plate, and the base backing plate is fixed below the test pile lower connecting plate.

[0013] In one embodiment, a eye plate is arranged on the side surface of any one of the first columns, and the eye plate is used for the hoisting of the base.

[0014] In one embodiment, guide pins are provided on the upper end surfaces of at least two first columns, and positions of the guide pins correspond to positions of guide holes in the lower blowout preventer or the lower riser assembly.

[0015] The second aspect of the present application provides a pressure test operation method, which includes: installing the base provided in the first aspect of the present application on the deck; using a crane to lift the pressure test pile onto the base, and fixedly connecting the pressure test pile to the horizontal frame of the base; using a crane to lift the lower blowout preventer or the lower watertight pipe assembly onto the base, and fixedly connecting the lower blowout preventer or the lower watertight pipe assembly to the vertical frame of the base; sealingly connecting the lower blowout preventer or the lower watertight pipe assembly to the pressure test pile; installing a sealing plug at one end of the pressure test drill pipe; inserting the pressure test drill pipe into the underwater blowout preventer group so that the sealing plug reaches the designated sealing position to seal the pressure test area; and performing a pressure test operation on the pressure test area.

[0016] Compared with the prior art, the base and pressure testing method for an underwater blowout preventer assembly according to the present invention have the following advantages:

[0017] The base of the embodiment of the present application integrates a horizontal frame, a vertical frame, a pressure test pile support structure and an oblique support structure. The horizontal frame provides a base foundation, and the pressure test pile support structure based on this can provide support and fixation for the pressure test piles, and the vertical frame provides support and fixation for the larger lower blowout preventer or lower watertight pipe assembly, thus realizing the combination of the functions of multiple bases. The oblique support structure not only strengthens the horizontal frame and the vertical frame, but also reduces the interference with the hoisting pressure test piles and reduces the difficulty of hoisting. Since multiple bases are combined together, there is no need to install bases with other functions on the deck. One base can complete the installation and pressure testing of related equipment for various pressure test scenarios, thereby reducing the occupancy of the deck. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a base exemplarily shown in an embodiment of the present application.

[0019] Figure 2 It is a schematic front view of a base exemplarily shown in an embodiment of the present application.

[0020] Figure 3 It is a left view schematic diagram of a base exemplarily shown in an embodiment of the present application.

[0021] Figure 4 It is a schematic top view of a base exemplarily shown in an embodiment of the present application.

[0022] Figure 5 It is a schematic cross-sectional view at AA of a base exemplarily shown in an embodiment of the present application.

[0023] Figure 6 It is a left - view assembly schematic diagram of a base and a lower blowout preventer, which is exemplarily shown in an embodiment of the present application.

[0024] Figure 7 It is a left - view assembly schematic diagram of a base and a riser assembly, which is exemplarily shown in an embodiment of the present application.

[0025] Figure 8 It is a flow schematic diagram of a pressure - testing operation method, which is exemplarily shown in an embodiment of the present application.

[0026] Reference numerals:

[0027] 1, deck; 2, base; 3, pressure - testing pile; 4, lower blowout preventer; 5, lower riser assembly; 6, extension joint; 21, horizontal frame; 22, vertical frame; 23, diagonal support structure; 24, pressure - testing pile support structure; 201, column base backing plate; 202, column lower connecting plate; 203, first column; 204, horizontal connecting plate; 205, eye plate; 206, first horizontal beam; 207, first vertical connecting plate; 208, second vertical connecting plate; 209, guide pin; 210, second column; 211, second horizontal beam; 212, third horizontal beam; 213, diagonal support beam; 214, fourth horizontal beam; 215, fifth horizontal beam; 216, first reinforcing gusset; 217, base backing plate; 218, pressure - testing pile lower connecting plate; 219, pressure - testing pile support pipe; 220, second reinforcing gusset; 221, pressure - testing pile upper connecting plate. Detailed implementation manners

[0028] The following will further describe in detail the specific implementation manners of the present application in combination with the drawings and embodiments. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0029] In the description of the present application, it should be understood that terms such as "first", "second", etc. in the specification, claims and the above - mentioned drawings of the present application are intended to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that under appropriate circumstances, such terms can be interchanged so that the embodiments of the present application can be implemented in a manner other than the illustrated or described manner. In addition, "including", "having" and any of their deformations are intended to cover non - exclusive inclusion. For example, a process, method, system, product or device including a series of components, steps or units does not necessarily have to be limited to those components, steps or units clearly listed, but may also include other components, steps or units inherent to these processes, methods, products or devices. In the present application, any vertical frame is perpendicular to the horizontal frame.

[0030] In the current offshore oil and gas exploration field, the subsea blowout preventer (BOP) stack, as a critically important safety device, can weigh up to 400 tons. According to the traditional structure, the subsea BOP stack consists of a lower riser assembly and a lower BOP. Generally, these two parts are arranged separately and then assembled in a specific area and the overall pressure test operation is carried out subsequently.

[0031] However, this traditional layout mode requires the fabrication and installation of various types of bases. The separate installation of multiple bases will occupy a large amount of deck space on the offshore platform, resulting in low utilization rate of this valuable area of the deck, which severely restricts the layout and operation of other key equipment.

[0032] As Figures 1-7 shown, a base 2 for a subsea BOP stack in a preferred embodiment of the present application can include: a horizontal frame 21, a vertical frame 22, a test pile support structure 24, and an inclined support structure 23.

[0033] The horizontal frame 21 and the vertical frame 22 are square beam-column structures. The bottom edges of the two vertical frames 22 are co-edged with two opposite sides of the horizontal frame 21 respectively. The lower BOP 4 or the lower riser assembly 5 is installed above the vertical frame 22. The inclined support structure 23 is fixedly connected between the first side of the vertical frame 22 and the second side of the horizontal frame 21. The first side and the second side are adjacent, and the first side and the second side are perpendicular to the co-edged sides respectively. The test pile support structure 24 is fixed at the center of the horizontal frame 21, and the test pile support structure 24 is used to connect the test pile 3.

[0034] The base 2 of the present application integrates the functions of supporting the subsea BOP stack and the test pile 3, changing the situation of the traditional need for multiple bases. In terms of the utilization of the offshore platform space, only this one base 2 needs to be installed to achieve the tasks that originally required multiple bases, greatly reducing the occupation of the deck 1 space. Compared with the traditional mode, a large amount of deck 1 space can be saved, creating conditions for the layout and operation of other key equipment. For example, the saved space can be used to place more advanced oil and gas extraction auxiliary equipment to improve the extraction efficiency. In addition, the increased design of the test pile base enables the alignment work of the test pile, the lower riser assembly, the lower BOP, and the base of the subsea BOP stack to be completed during the in-field fabrication stage, which effectively reduces the on-site construction volume in complex environments. And the base 2 of the present application is an integrally detachable structure, which can be adjusted and adapted according to the switching requirements of other operation modes and has the function of overall base interchange, which further improves the deck utilization rate, enables the space of the offshore platform to be used more reasonably and efficiently, and brings more convenience and benefits to the offshore oil and gas extraction operation.

[0035] The square beam-column frame has a regular shape, with a uniform force distribution. The horizontal and vertical frames 22 are perpendicularly connected, initially resisting wind and waves, equipment gravity, and pressure testing pressure. The diagonal bracing structure 23 further strengthens the whole, connecting the vertical and horizontal frames 21, decomposing the diagonal wind and wave impact force, making the force on the square frame system more balanced, avoiding excessive local force, reducing stress concentration, enhancing stability under complex working conditions, and firmly supporting the subsea blowout preventer group and the pressure testing pile 3.

[0036] In the design stage, due to its regular geometric shape, the square beam-column structure frame can flexibly adjust parameters such as the side length of the frame and the cross-sectional dimensions of the beams and columns according to the size requirements of different subsea blowout preventer groups and pressure testing piles 3.

[0037] In an embodiment of the present application, a unique frame structure is provided. Specifically, the horizontal frame 21 may include two mutually parallel second horizontal beams 211 and two mutually parallel fourth horizontal beams 214. The two second horizontal beams 211 and the two fourth horizontal beams 214 form a quadrilateral structure, and the two second horizontal beams 211 are the common sides of the horizontal frame 21 and the vertical frame 22.

[0038] The vertical frame 22 includes four first columns 203, four column lower connecting plates 202, and two first horizontal beams 206. The first horizontal beam 206 is parallel to the second horizontal beam 211. Each column lower connecting plate 202 is fixedly connected to the lower end face of one of the first columns 203. The two first horizontal beams 206 are mutually parallel, and the two first horizontal beams 206 are respectively fixedly connected to the upper ends of the two first columns 203. The lower ends of the four first columns 203 are respectively fixedly connected to the four corners of the quadrilateral structure.

[0039] The pressure testing pile support structure 24 is at the same height as the horizontal frame 21. The pressure testing pile support structure 24 includes two collinear third horizontal beams 212, two collinear fifth horizontal beams 215, a pressure testing pile support pipe 219, and a pressure testing pile upper connecting plate 221. Any one of the third horizontal beams 212 is perpendicular to any one of the fifth horizontal beams 215. The third horizontal beam 212 is fixed between the pressure testing pile support pipe 219 and the second horizontal beam 211, and the fifth horizontal beam 215 is fixed between the pressure testing pile support pipe 219 and the fourth horizontal beam 214, so that the pressure testing pile support pipe 219 is fixed in the middle of the horizontal frame 21. The pressure testing pile upper connecting plate 221 is fixed to the upper part of the pressure testing pile support pipe 219, and the pressure testing pile upper connecting plate 221 is used to connect the pressure testing pile 3.

[0040] The diagonal bracing structure 23 may include four diagonal bracing beams 213. The two ends of any one of the diagonal bracing beams 213 are respectively fixedly connected to the adjacent first column 203 and the fourth horizontal beam 214.

[0041] In terms of the horizontal frame 21, a quadrilateral is formed by two second horizontal beams 211 and two fourth horizontal beams 214, sharing a side with the vertical frame 22 to construct a stable foundation, ensuring uniform force distribution in the horizontal direction of the overall structure and enabling better response to complex horizontal forces at sea, such as wind and wave impacts. The vertical frame 22 is connected by four first columns 203 and corresponding connecting plates and horizontal beams to form a solid vertical support system, enhancing the vertical load-bearing capacity of the structure and stably supporting the huge weights of underwater blowout preventers 4, lower riser assemblies 5, and other underwater blowout preventer groups. The test pile support structure 24 is ingeniously designed. The test pile support pipe 219 is fixed in the middle of the horizontal frame 21, making the connection position of the test pile 3 accurate, and the beams are perpendicularly fixed to each other, ensuring the stability of the test pile 3 during the pressure test and ensuring uniform pressure conduction. The four diagonal support beams 213 of the diagonal support structure 23 connect the first column 203 and the fourth horizontal beam 214, effectively dispersing and transferring forces in all directions, further enhancing the overall structural stability, reducing stress concentration, and providing a reliable equipment support framework for offshore oil and gas exploitation operations.

[0042] In the present application, a column base backing plate 201 can also be provided below each lower connecting plate 202 of the column. The column base backing plate 201 is used to cover bolts, welding marks, etc., reducing wear of the device and the deck 1.

[0043] In addition, in the present application, when it is necessary to switch operations, the existing base can be removed to vacate deck space for arranging other operating equipment.

[0044] In one embodiment, the vertical frame 22 can further include at least one second column 210. The length of the second column 210 is shorter than that of the first column 203, and the second column 210 is fixedly connected between the first horizontal beam 206 and the second horizontal beam 211.

[0045] In terms of the vertical load-bearing capacity, the second column 210 shares part of the vertical load. The underwater blowout preventer group is extremely heavy. Although the first column 203 bears the main support, after adding the second column 210, the additional support points make the overall vertical support more stable, further ensuring that the structure does not undergo excessive deformation or damage when carrying heavy loads.

[0046] On this basis, second vertical connecting plates 208 can be welded at corresponding positions of the first horizontal beam 206 and the second horizontal beam 211 to strengthen the structure and transfer forces.

[0047] In another embodiment, second vertical connecting plates 208 can be welded on the inner side at the contact position of the fourth horizontal beam 214 and the diagonal support beam 213 to further enhance the structure.

[0048] In one embodiment, the horizontal frame 21 may further include a horizontal connecting plate 204. The fourth horizontal beam 214 is flush with the second horizontal beam 211 in height. The fourth horizontal beam 214, the first column 203 and the second horizontal beam 211 are welded through the horizontal connecting plate 204.

[0049] The fact that the fourth horizontal beam 214 is flush with the second horizontal beam 211 in height enables welding through the same horizontal connecting plate 204, greatly simplifying the structure. Compared with setting connection structures for each component separately, it reduces various connecting pieces and corresponding installation processes, and reduces the material procurement cost and the manual installation cost.

[0050] The horizontal connecting plate 204 tightly connects the fourth horizontal beam 214, the first column 203 and the second horizontal beam 211 to form a stable planar structure, which can effectively disperse stress and avoid excessive single-point stress. And the unified horizontal connecting plate 204 is convenient for on-site installation operation. The installer does not need complex positioning and adjustment, and only needs to weld each component to the horizontal connecting plate 204 according to the established position.

[0051] In one embodiment, the base 2 may further include a first reinforcing gusset 216. The two right-angled sides of the first reinforcing gusset 216 are respectively welded to the fourth horizontal beam 214 and the first column 203.

[0052] Setting the first reinforcing gusset 216 in the base 2 strengthens the connection between the fourth horizontal beam 214 and the first column 203, prevents cracking and deformation, improves the bearing capacity, stabilizes the base 2, and ensures the safe operation of the underwater equipment.

[0053] The reinforcing gusset reduces the wear and fatigue damage at the connection. The reinforcing gusset disperses the force, reduces the fatigue risk, prolongs the service life of the component, reduces maintenance and replacement, and saves costs.

[0054] In another embodiment of the present application, the test pile support structure 24 may further include a test pile lower connecting plate 218 and a second reinforcing gusset 220. The upper part of the second reinforcing gusset 220 is welded to the third horizontal beam 212 or the fifth horizontal beam 215, the side part of the second reinforcing gusset 220 is welded to the test pile support pipe 219, and the lower part of the second reinforcing gusset 220 is welded to the test pile lower connecting plate 218.

[0055] The second reinforcing gusset 220 is used to jointly bear the vertical force and part of the horizontal force from the lower blowout preventer 4 or the lower riser assembly 5 and the test pile 3 with the test pile support pipe 219.

[0056] Specifically, the second reinforcing gusset 220 can share the vertical pressure by virtue of its welded connection with the test pile support pipe 219. It is like an additional "lever arm", which evenly disperses part of the vertical force to the test pile lower connecting plate 218 and the relevant horizontal beams, and reduces the vertical load borne by the test pile support pipe 219 alone.

[0057] On the side of the second reinforcing gusset plate 220, it is welded to the pressure test pile support pipe 219, and on the upper part, it is welded to the horizontal beam, enabling it to cooperate with the pressure test pile support pipe 219 to resist horizontal forces. When a horizontal external force acts, the second reinforcing gusset plate 220 can decompose the horizontal force. Part of it is transmitted to the third horizontal beam 212 and the fifth horizontal beam 215, and the structural characteristics of the horizontal beam are used to disperse the horizontal force. The other part is transmitted to the lower connecting plate 218 of the pressure test pile through its own structure, and then the lower connecting plate 218 of the pressure test pile conducts the force to the entire base 2, effectively reducing the force-bearing burden of the pressure test pile support pipe 219 in the horizontal direction.

[0058] In one embodiment, the pressure test pile support structure 24 may further include a base backing plate 217, and the base backing plate 217 is fixed below the lower connecting plate 218 of the pressure test pile.

[0059] The base backing plate 217 increases the contact area between the support structure and the foundation, disperses the vertical force transmitted by the pressure test pile 3, reduces the pressure per unit area, and reduces the wear on the deck 1.

[0060] In one embodiment, a eye plate 205 is arranged on the side surface of any one of the first columns 203, and the eye plate 205 is used for the hoisting of the base 2.

[0061] Setting the eye plate 205 on the side surface of the first column 203 can make the hoisting force evenly distributed over the entire base structure. The first column 203 has a strong load-bearing capacity. The hoisting force is transmitted to it through the eye plate 205 and then dispersed to the vertical frame 22 and other structural parts, avoiding local stress concentration, reducing the risk of damage to the base structure, and ensuring its integrity during hoisting.

[0062] In one embodiment, guide pins 209 are provided on the upper end surfaces of at least two first columns 203, and the positions of the guide pins 209 correspond to the positions of the guide holes in the lower blowout preventer 4 or the lower riser assembly 5.

[0063] In terms of the convenience of positioning and alignment, the guide pin 209 is like an accurate "positioning pin", providing efficient assistance for the installation of the lower blowout preventer 4 or the lower riser assembly 5. Two or more guide pins 209 can not only provide guiding in the vertical direction to enable the smooth contact of the contact surfaces of the two devices. It can also provide a limiting function in the horizontal direction. This limiting function enables the lower blowout preventer 4 or the riser assembly to be directly aligned with the installed pressure test pile 3 after being placed according to the guide pin 209, reducing the steps of secondary alignment, reducing the construction difficulty, and shortening the construction time.

[0064] In addition, the guide pin can also bear a part of the horizontal load generated by the movement of the lower blowout preventer 4 or the lower riser assembly 5, further optimizing and dispersing the force-bearing situation of the base.

[0065] In a further embodiment, a first vertical connecting plate 207 and a second vertical connecting plate 208 may be provided below the guide pin 209 to reliably strengthen the structure of the guide pin 209.

[0066] In any embodiment of the present application, structures such as beams and columns in the present application may be made of materials with the same cross-section. For example, an H-shaped steel structure is used, and the connecting plate is perpendicular to the vertical web, serving as an extension of the horizontal flange of the butt joint beam / column and transmitting the force.

[0067] It can be understood that for some sizes of the pressure test pile 3, by hoisting the lifting short section 6 onto the upper connecting plate 221 of the pressure test pile and connecting it to the pressure test pile 3, the overall structure height can be increased, enabling the lower riser assembly 5 to be in a suitable position to meet the space requirements of the local pressure test operation.

[0068] Such as Figure 8 As shown, correspondingly, the present application also provides a pressure test operation method, which may include:

[0069] S101. Install the base 2 provided in the first aspect of the present application on the deck 1.

[0070] S102. Use a crane to lift the pressure test pile 3 onto the base 2 and fixedly connect the pressure test pile 3 to the horizontal frame 21 of the base 2.

[0071] S103. Place a sealing steel ring on the pressure test pile 3;

[0072] S104. Use a crane to lift the lower blowout preventer 4 or the lower riser assembly 5 onto the base 2 and fixedly connect the lower blowout preventer 4 or the lower riser assembly 5 to the vertical frame 22 of the base 2.

[0073] S105. Lock and connect the lower blowout preventer 4 or the lower riser assembly 5 to the pressure test pile 3.

[0074] S106. Install a sealing plug at one end of the pressure test drill pipe.

[0075] S107. Insert the pressure test drill pipe into the internal part of the subsea blowout preventer group so that the sealing plug reaches the designated sealing position to block the pressure test area.

[0076] S108. Conduct a pressure test operation on the pressure test area.

[0077] In the above embodiment, in step S103, placing a sealing steel ring on the pressure test pile 3 ensures the sealing between the pressure test pile 3 and other components, enabling the pressure test work to proceed smoothly.

[0078] An embodiment of the base 2 for an underwater blowout preventer stack described in this application and the beneficial effects it possesses are equally applicable to a pressure testing operation method provided by this application. In this pressure testing operation method, the unique structural design of the base 2, such as the specific implementation manners of the horizontal frame 21, the vertical frame 22, the diagonal support structure 23, the test pile support structure 24, etc., provides a solid foundation for the smooth progress of the pressure testing operation process. Through beneficial effects such as enhancing structural stability, optimizing space utilization, and reducing costs, it directly acts on all aspects of the pressure testing operation, including equipment installation and positioning, pressure conduction and control during the pressure testing process, reducing operation time and costs, etc., powerfully guaranteeing the efficiency, accuracy, and safety of the pressure testing operation.

[0079] Compared with the prior art, a base 2 for an underwater blowout preventer stack and a pressure testing operation method in this application have the beneficial effects that:

[0080] The base 2 of the embodiment of this application combines the horizontal frame 21, the vertical frame 22, the test pile support structure 24, and the diagonal support structure 23. The horizontal frame 21 provides the base foundation. On this basis, the test pile support structure 24 can provide support and fixation for the test pile 3. The vertical frame 22 provides support and fixation for the larger-sized lower blowout preventer 4 or the lower riser assembly 5, realizing the compounding of the functions of multiple bases. The diagonal support structure 23 not only strengthens the horizontal frame 21 and the vertical frame 22, but also can reduce the interference with the hoisting of the test pile 3 and lower the hoisting difficulty. Since multiple bases are combined together, there is no need to install other bases with assembly functions on the deck 1. One base can complete the installation and pressure testing of related equipment for multiple pressure testing scenarios. Therefore, the occupation of the deck 1 is reduced.

[0081] The above is only the preferred embodiment of this application. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the technical principle of this application, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of this application.

Claims

1. A base for an underwater blowout preventer stack, characterized in that, Comprising: A horizontal frame (21), the horizontal frame (21) being a square beam-column structure; Two vertical frames (22), the vertical frames (22) being square beam-column structures, the bottom edges of the two vertical frames (22) being co-edged with two opposite sides of the horizontal frame (21), and a lower blowout preventer (4) or a lower riser assembly (5) being installed above the vertical frames (22); An inclined support structure (23), the inclined support structure (23) being fixedly connected between a first side of the vertical frame (22) and a second side of the horizontal frame (21), the first side and the second side being adjacent, and the first side and the second side being perpendicular to the bottom edge of the vertical frame (22) respectively; A test pile support structure (24), the test pile support structure (24) being fixed at the center of the horizontal frame (21), and the test pile support structure (24) being used for connecting a test pile (3).

2. The base according to claim 1, wherein The horizontal frame (21) comprises two second horizontal beams (211) parallel to each other and two fourth horizontal beams (214) parallel to each other, the two second horizontal beams (211) and the two fourth horizontal beams (214) forming a quadrilateral structure, and the two second horizontal beams (211) being the co-edges of the horizontal frame (21) and the vertical frames (22); The vertical frame (22) comprises four first columns (203), four column lower connecting plates (202) and two first horizontal beams (206), the first horizontal beams (206) being parallel to the second horizontal beams (211), each column lower connecting plate (202) being fixedly connected to the lower end face of one of the first columns (203) correspondingly, the two first horizontal beams (206) being parallel to each other, and the two first horizontal beams (206) being fixedly connected to the upper ends of two of the first columns (203) respectively, and the lower ends of the four first columns (203) being fixedly connected to the four corners of the quadrilateral structure; The test pile support structure (24) is at the same height as the horizontal frame (21), the test pile support structure (24) comprises two third horizontal beams (212) collinear with each other, two fifth horizontal beams (215) collinear with each other, a test pile support pipe (219) and a test pile upper connecting plate (221), any one of the third horizontal beams (212) being perpendicular to any one of the fifth horizontal beams (215), the third horizontal beam (212) being fixed between the test pile support pipe (219) and the second horizontal beam (211), the fifth horizontal beam (215) being fixed between the test pile support pipe (219) and the fourth horizontal beam (214), so that the test pile support pipe (219) is fixed in the middle of the horizontal frame (21), and the test pile upper connecting plate (221) is fixed to the upper part of the test pile support pipe (219), and the test pile upper connecting plate (221) is used for connecting the test pile (3); The diagonal support structure (23) includes four diagonal support beams (213), and both ends of any one of the diagonal support beams (213) are fixedly connected to the adjacent first vertical column (203) and the fourth horizontal beam (214) respectively.

3. The base according to claim 2, wherein The vertical frame (22) further includes at least one second vertical column (210), the length of the second vertical column (210) is shorter than that of the first vertical column (203), and the second vertical column (210) is fixedly connected between the first horizontal beam (206) and the second horizontal beam (211).

4. The base according to claim 2, characterized in that, The horizontal frame (21) further includes a horizontal connecting plate (204), the fourth horizontal beam (214) is flush with the second horizontal beam (211) in height, and the fourth horizontal beam (214), the first vertical column (203) and the second horizontal beam (211) are welded through the horizontal connecting plate (204).

5. The base according to claim 4, characterized in that, The base (2) further includes a first reinforcing gusset plate (216), and two right-angled sides of the first reinforcing gusset plate (216) are welded to the fourth horizontal beam (214) and the first vertical column (203) respectively.

6. The base according to claim 2, wherein The test pile support structure (24) further includes a test pile lower connecting plate (218) and a second reinforcing gusset plate (220); The upper part of the second reinforcing gusset plate (220) is welded to the third horizontal beam (212) or the fifth horizontal beam (215), the side part of the second reinforcing gusset plate (220) is welded to the test pile support pipe (219), and the lower part of the second reinforcing gusset plate (220) is welded to the test pile lower connecting plate (218).

7. The base according to claim 6, characterized in that, The test pile support structure (24) further includes a base backing plate (217), and the base backing plate (217) is fixed below the test pile lower connecting plate (218).

8. The base according to claim 2, wherein, Eye plates (205) are arranged on the side surface of any one of the first vertical columns (203), and the eye plates (205) are used for hoisting the base (2).

9. The base according to claim 2, characterized in that, Guide pins (209) are arranged on the upper end surfaces of at least two of the first vertical columns (203), and the positions of the guide pins (209) correspond to the positions of the guide holes in the lower blowout preventer (4) or the lower riser assembly (5).

10. A pressure test operation method, characterized in that, The test operation method includes: Install the base (2) as described in any one of claims 1-9 on the deck (1); Use a crane to lift the test pile (3) onto the base (2), and fixedly connect the test pile (3) with the horizontal frame (21) of the base (2); Place a sealing steel ring on the test pile (3); Use the crane to lift the lower blowout preventer (4) or the lower riser assembly (5) onto the base (2), and fixedly connect the subsea blowout preventer group or the lower riser assembly (5) with the vertical frame (22) of the base (2); Lock and connect the subsea blowout preventer group or the lower riser assembly (5) with the test pile (3); Install a sealing plug at one end of the test drill pipe; Insert the test drill pipe into the interior of the subsea blowout preventer group so that the sealing plug reaches the specified sealing position to block the test area; Conduct a pressure test on the test area.

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