Wellhead blowout preventer for testing

Abstract

The utility model discloses a wellhead blowout preventer for testing, and belongs to the technical field of exploration. Comprising a storage tank, a choke pipe and a blowout prevention pipe, an upper joint is arranged at the top of the choke tube; the storage tank is connected with the grease injection connector through a grease injection pipeline with a pump, and the grease return connector is connected with the storage tank through a grease return pipeline; the middle and the lower portion of the choke pipe are both located in the blowout prevention pipe, the lower end of the choke pipe is located on the lower portion of the blowout prevention pipe, the length of the choke pipe is larger than 1.2 m, and the choke pipe is composed of N sub choke pipes. A middle connector is arranged between every two adjacent sub-choke pipes, the outer walls of the middle connectors protrude outwards relative to the choke pipes and are fixed to the anti-spraying pipe, the grease injection connector is arranged on the second sub-choke pipe, the grease return connector is arranged on the uppermost sub-choke pipe, the uppermost middle connector is fixed to the top of the anti-spraying pipe, and the grease injection pipeline penetrates through the anti-spraying pipe. The length of the sub-choke pipe at the lowest end is larger than or equal to 30 cm. The device can save the use amount of sealing grease.

Description

Technical Field

[0001] This utility model belongs to the field of exploration technology, and specifically relates to a wellhead blowout prevention device for testing. Background Technology

[0002] Blowout preventers are essential wellhead cable sealing devices for logging operations. These devices connect directly to the wellhead and effectively prevent well fluid overflow caused by excessive downhole pressure during logging operations, thus preventing blowout accidents. They also reduce well fluid outflow and well site pollution caused by logging operations, making them an essential safety and environmental protection measure for logging operations.

[0003] In existing technologies, cables can be sealed using a flow-blocking tube, through which sealing grease is introduced. For example, patent application number CN200920161409.6 discloses a grease-filled cable sealing anti-spray box, in which an upper connector and a lower connector are respectively connected to the upper and lower ends of the upper flow-blocking tube, the lower end of the lower connector is connected to the lower flow-blocking tube, the upper connector is connected to a grease return interface assembly, the lower connector is connected to a grease injection connector assembly with a needle valve, the upper end of the upper connector is connected to a sealing overflow device, and the lower end of the lower flow-blocking tube is connected to a spring rebound buffer device. For example, patent application number CN201520648825.4 discloses a sealing device for a flow-blocking pipe. The flow-blocking pipe assembly includes a flow-blocking pipe, a blowout preventer, and a wellhead connector connected to an oil well, and a fixing frame coaxially arranged with the flow-blocking pipe, connected in sequence. The sealing device includes a grease injection assembly and a recovery assembly connected to the flow-blocking pipe respectively. The grease injection assembly includes a storage tank and a hydraulic pump disposed on the storage tank. The recovery assembly includes a filter bucket and a filter screen disposed on the upper end of the filter bucket.

[0004] To reduce grease usage, existing technologies can design more complex flow-blocking pipes, such as adding corresponding sealing structures; however, this significantly increases costs and installation difficulty. If flow-blocking pipes (usually less than 0.5m) are used directly, the amount of grease used is large (when the wellhead pressure is 25MPa and the cable diameter is 5.6mm, the amount of sealing grease used for 10 days is 40-60kg). Utility Model Content

[0005] To address the aforementioned problems, this utility model provides a test wellhead blowout preventer that achieves good sealing performance using a simple flow-blocking pipe, reducing the amount of sealing grease required. The technical solution is as follows:

[0006] This utility model embodiment provides a test wellhead blowout preventer device, which includes a storage tank 1, a flow-blocking pipe 2, and a blowout preventer pipe 3. Both the flow-blocking pipe 2 and the blowout preventer pipe 3 are vertically arranged. The lower end of the blowout preventer pipe 3 is provided with a wellhead connector 4. The top of the flow-blocking pipe 2 is provided with an upper connector 5, with a grease return port 6 at its upper part and a grease injection port 7 at its lower part. The storage tank 1 is connected to the grease injection port 7 via a grease injection line 8 with a pump, and the grease return port 6 is connected to the storage tank 1 via a grease return line 9. The middle and lower parts of the flow-blocking pipe 2 are located inside the blowout preventer pipe 3, with its lower end... Located at the lower part of the blowout preventer 3, its length is greater than 1.2m, and it consists of N sub-choke tubes; an intermediate joint 10 is provided between two adjacent sub-choke tubes, the outer wall of the intermediate joint 10 protrudes towards the choke tube 2 and is fixed on the blowout preventer 3, the grease injection port 7 is located on the second sub-choke tube, the grease return port 6 is located on the uppermost sub-choke tube, the uppermost intermediate joint 10 is fixed to the top of the blowout preventer 3, the grease injection line 8 passes through the blowout preventer 3, N is an integer greater than or equal to 3, and the length of the lowermost sub-choke tube is greater than or equal to 30cm.

[0007] In this embodiment of the invention, the flow-blocking pipe 2 and the blowout preventer 3 are coaxially arranged, and the wellhead connector 4, the upper connector 5 and the intermediate connector 10 are all coaxially arranged with the flow-blocking pipe 2.

[0008] Specifically, in this embodiment of the invention, the length of the sub-flow-blocking tube is 30-50cm.

[0009] Furthermore, in this embodiment of the present invention, a vent valve 11 is provided at the lower part of the blowout preventer 3 and below the flow control pipe 2.

[0010] In this embodiment of the invention, the inner diameter of the flow-blocking tube 2 is 0-2 mm larger than the diameter of the cable 12.

[0011] Specifically, in this embodiment of the present invention, the grease injection port 7 is located adjacent to and above the lowest intermediate connector 10, and the grease return port 6 is located above the highest sub-flow-blocking tube.

[0012] Preferably, in this embodiment of the present invention, the blowout preventer 3 is composed of N-1 segments of blowout preventer, and two adjacent segments of blowout preventer are detachably connected by an intermediate joint 10.

[0013] Specifically, in this embodiment of the present invention, all sub-flow-blocking tubes are 40cm long, there are 3 intermediate joints 10, 4 sub-flow-blocking tubes, and 3 sub-blowout preventers.

[0014] The beneficial effects of the technical solution provided by this utility model embodiment are:

[0015] (1) The flow control tube is extended, extending upward and downward relative to the upper end of the blowout preventer, thereby improving the sealing effect;

[0016] (2) Due to the elongated choke tube, in order to avoid deformation of the choke tube, the middle and upper parts of the blowout preventer are used as a fixing structure to fix the choke tube, while the lower part serves as a blowout preventer.

[0017] (3) The downward extension of the upper end of the blowout preventer not only lengthens the blowout preventer, but also increases the distance between the grease return port and the lower end of the flow barrier, reducing the amount of sealing grease flowing out from the lower end of the flow barrier.

[0018] (4) The amount of sealing grease used has been reduced. When the wellhead pressure is 25 MPa and the diameter of the cable is 5.6 mm, the amount of sealing grease used in 10 days is 15-30 kg, which is 1 / 3-1 / 2 of the existing technology (short choke tube, with the lower end of the choke tube inserted at the upper end of the blowout preventer).

[0019] (5) Tests have shown that the maximum sealing pressure at the wellhead can reach 45 MPa;

[0020] (6) The cost is low, and the main sealing structure is a flow-blocking tube, so there is no need to add other sealing structures. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the existing test wellhead blowout preventer.

[0022] Figure 2 This is a schematic diagram of the structure of the test wellhead blowout preventer in this embodiment of the present invention.

[0023] In the diagram: 1 Storage tank, 2 Blowout pipe, 3 Blowout preventer, 4 Wellhead connector, 5 Upper connector, 6 Grease return port, 7 Grease injection port, 8 Grease injection line, 9 Grease return line, 10 Intermediate connector, 11 Vent valve, 12 Cable. Detailed Implementation

[0024] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.

[0025] Example 1

[0026] See Figure 2Example 1 provides a test wellhead blowout preventer (BOP) device, which includes a storage tank 1, a flow-blocking pipe 2, and a blowout preventer 3. Both the flow-blocking pipe 2 and the blowout preventer 3 are vertically arranged and coaxially. A wellhead connector 4 (consistent with existing technology) is coaxially located at the lower end of the blowout preventer 3, and a vent valve 11 (specifically a ball valve or butterfly valve, etc.) is located below the flow-blocking pipe 2. An upper connector 5 is coaxially located at the top of the flow-blocking pipe 2, consistent with existing technology. The middle and lower parts of the flow-blocking pipe 2 are located inside the blowout preventer 3, with its lower end at the bottom of the blowout preventer 3. Its length is greater than 1.2m, and it consists of N segments of flow-blocking pipes, with an inner diameter 0-2mm larger than the diameter of the cable 12. Here, N is an integer greater than or equal to 3, specifically 3, 4, or 5. The length of the sub-choke tube is 30-50cm, with the length of the lowest sub-choke tube being greater than or equal to 30cm (the sealing grease is sprayed from the bottom). Specifically, the sub-choke tube is a common metal choke tube. An intermediate connector 10 is provided between two adjacent sub-choke tube sections. The intermediate connector 10 is coaxially arranged with the choke tube 2, and it has a ring structure. Its outer wall protrudes towards the choke tube 2 and is fixed to the blowout preventer 3. Its structure can be referred to as the lower connector in the prior art. The second section (counting from bottom to top) of the sub-choke tube is provided with a grease injection port 7; specifically, the grease injection port 7 is located adjacent to and above the lowest intermediate connector 10. The uppermost sub-choke tube is provided with a grease return port 6; specifically, the grease return port 6 is located at the upper part of the uppermost sub-choke tube. The uppermost intermediate connector 10 is fixed to the top of the blowout preventer 3 to seal the top of the blowout preventer 3. Storage tank 1 (containing sealing grease) is connected to grease injection port 7 via grease injection line 8 with pump to output sealing grease. Grease return port 6 is connected to storage tank 1 via grease return line 9 to recover sealing grease. Storage tank 1 is located below storage tank 1. Grease injection line 8 passes through blowout preventer 3.

[0027] Example 2

[0028] See Figure 2 Example 2 provides a test wellhead blowout preventer, whose structure is basically the same as that of Example 1, except that: the blowout preventer 3 in this embodiment is composed of N-1 sub-blowout preventer sections, and adjacent sub-blowout preventer sections are detachably connected by an intermediate joint 10 (e.g., by internal and external threads). The length of the lowest sub-blowout preventer section is set according to the actual situation, and the lengths of the other sub-blowout preventers are approximately the same as the lengths of the corresponding sub-chokes. The sub-chokes are detachably connected to the intermediate joint 10. This structure facilitates transportation.

[0029] Example 3

[0030] See Figure 2Example 3 provides a test wellhead blowout preventer, whose structure is basically the same as that of Example 2, except that: in this embodiment, all sub-flow preventers are 40cm long, there are 3 intermediate joints 10, 4 sub-flow preventer segments, and 3 sub-blowout preventer segments. Therefore, the total length of the flow preventer 2 is 1.4m. Except for the lowest sub-blowout preventer segment, the length of the other sub-blowout preventers is approximately 40cm.

[0031] Example 4

[0032] See Figure 2 Example 4 provides a test wellhead blowout preventer, whose structure is basically the same as that of Example 2. The difference is that the intermediate joint 10 in this utility model embodiment is detachably connected to the sub-flow preventer (with external thread at the end) by a thread.

[0033] Example 5

[0034] See Figure 2 Example 5 provides a test wellhead blowout preventer, whose structure is basically the same as that of Example 1, except that the diameter of the cable 12 in this embodiment is 5.60 mm, and the inner diameter of the flow-blocking tube 2 is 5.60 mm-5.61 mm. This ensures that the cable 12 can slide while minimizing the amount of sealant used. Testing showed that at a wellhead pressure of 25 MPa, the wellhead seal was good, and the amount of sealant used over 10 days was approximately 16.7 kg.

[0035] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A wellhead blowout preventer for testing, comprising a storage tank (1), a choke pipe (2) and a blowout preventer pipe (3), the choke pipe (2) and the blowout preventer pipe (3) are vertically arranged, the lower end of the blowout preventer pipe (3) is provided with a wellhead joint (4); the top of the choke pipe (2) is provided with an upper joint (5), the upper part thereof is provided with a grease return interface (6), and the lower part thereof is provided with a grease injection interface (7); the storage tank (1) is connected with the grease injection interface (7) through a grease injection pipeline (8) with a pump, and the grease return interface (6) is connected with the storage tank (1) through a grease return pipeline (9); characterized in that, the middle and lower parts of the choke pipe (2) are located in the blowout preventer pipe (3), the lower end thereof is located in the lower part of the blowout preventer pipe (3), the length thereof is greater than 1.2 m, and the choke pipe (2) is composed of N sub-choke pipes; an intermediate joint (10) is arranged between two adjacent sub-choke pipes, the outer wall of the intermediate joint (10) is protruded relative to the choke pipe (2) and is fixed on the blowout preventer pipe (3), the grease injection interface (7) is arranged on the second sub-choke pipe, the grease return interface (6) is arranged on the uppermost sub-choke pipe, the uppermost intermediate joint (10) is fixed on the top of the blowout preventer pipe (3), the grease injection pipeline (8) passes through the blowout preventer pipe (3), N is an integer greater than or equal to 3, and the length of the lowermost sub-choke pipe is greater than or equal to 30 cm.

2. The test wellhead blowout preventer according to claim 1, characterized in that, The choke pipe (2) and the blowout preventer pipe (3) are coaxially arranged, the wellhead joint (4), the upper joint (5) and the intermediate joint (10) are coaxially arranged with the choke pipe (2).

3. The test wellhead blowout preventer according to claim 2, characterized in that, The length of the sub-choke pipe is 30-50 cm.

4. The test wellhead blowout preventer of claim 1, wherein, The lower part of the blowout preventer pipe (3) and below the choke pipe (2) is provided with a vent valve (11).

5. The test wellhead blowout preventer of claim 1, wherein, The inner diameter of the choke pipe (2) is 0-2 mm larger than the diameter of the cable (12).

6. The test wellhead blowout preventer of claim 1, wherein, The grease injection interface (7) is located adjacent to the upper part of the lowermost intermediate joint (10), and the grease return interface (6) is located on the upper part of the uppermost sub-choke pipe.

7. The test wellhead blowout preventer of claim 3, wherein, The blowout preventer pipe (3) is composed of N-1 sub-blowout preventer pipes, and two adjacent sub-blowout preventer pipes are detachably connected through an intermediate joint (10).

8. The test wellhead blowout preventer according to claim 7, characterized in that The length of all sub-choke pipes is 40 cm, the number of intermediate joints (10) is 3, the number of sub-choke pipes is 4, and the number of sub-blowout preventer pipes is 3.

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