Safety rope socket for steel wire operation of oil and gas well and use method of safety rope socket

Abstract

The safety rope socket comprises a fishing head and a hanging sleeve adapter, the bottom of the fishing head is connected with the hanging sleeve adapter, an outer taper sleeve is arranged in the fishing head, an inner taper sleeve is arranged in the outer taper sleeve in a sleeved mode, and a plurality of upper open seams are evenly distributed in the outer surface of the top of the inner taper sleeve. A plurality of lower slits are uniformly distributed on the outer surface of the bottom of the inner taper sleeve, and the upper slits and the lower slits are arranged in a staggered manner; one end of the spring is connected with the gasket, and the other end of the spring is connected with the inner wall of the fishing head. The invention further discloses a using method of the safety rope socket for oil and gas well steel wire operation. According to the safety rope socket for the oil and gas well steel wire operation, the problems that an existing steel wire rope socket is fixedly connected with a steel wire, a downhole tool is clamped in an oil pipe and cannot slip out of a hand, the steel wire needs to be cut off, and the steel wire and a tool string in a shaft are left in a well, so that fishing difficulty and cost are greatly increased are solved, manpower and material resources can be saved, and operation cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field production technology, specifically relating to safety rope caps for wireline operations in oil and gas wells, and also to the method of using safety rope caps for wireline operations in oil and gas wells. Background Technology

[0002] In oil and gas field development, wireline operations are used throughout the entire process. Taking gas wells as an example, wireline operations are required for well testing, pressure testing, choke deployment and retrieval, and wireline retrieval for production recovery. Wireline operations involve connecting one end of a wireline to a wire rope cap, which in turn connects to other downhole tools, while the other end connects to a surface winch, which provides the power for the tools to move up and down within the wellbore. However, wireline operations currently face the same problem: if downhole tools become stuck in the wellbore, increasing the tension in the wireline to its breaking point can cause the tool string to fall into the well. In the event of a stuck tool string, the only solution is to cut the wireline and retrieve the fallen wireline and tools, which is difficult, carries significant safety risks, and is costly.

[0003] Chinese Patent (Application No.: 200810104964.5, Publication No.: CN101566051B, Publication Date: 2012-09-05) discloses a safety rope cap and a method for calculating the fuse of the safety rope cap. Specifically, it provides a safety rope cap with a fuse designed inside the tool. The fuse is broken by increasing the tensile force, thus separating the steel wire from the tool string. However, due to the limitation of the fuse material, it is only suitable for steel wires with a diameter of less than 3mm. Chinese Patent (Application No.: 201821802259.8, Publication No.: CN209430141U, Publication Date: 2019-09-24) discloses a rope cap assembly for oil and gas well downhole tools. It uses a snap-fit ​​component that breaks or deforms under force to detach the steel wire. Because the component has a small bearing capacity, it is only suitable for conventional steel wires with a diameter of less than 4mm. Chinese Patent (Application No.: 201821802259.8, Publication No.: CN209430141U, Publication Date: 2012-09-24) discloses a shear spike soluble wire rope cap, which uses a flux injected at the wellhead to dissolve the shear spikes and separate the wire rope from the stuck tubing. However, when there is a large amount of fluid in the wellbore, the flux is difficult to reach the downhole tools and thus fails to achieve a dissolving effect. Chinese Patent (Application No.: 202023181715.1, Publication No.: CN214375434U, Publication Date: 2021-10-08) discloses a novel fiber optic wire rope cap, but its internal clamping structure is made of soft material, resulting in very low tensile strength, making it unsuitable for downhole wire rope operations in oil and gas fields.

[0004] While the above technologies all provide design solutions for safety rope caps, due to limitations in structural design and material strength, they can only withstand a small ultimate pull-out force and are only suitable for conventional wire work (within 4mm in diameter). However, some wire work now requires increasingly larger wire diameters (8mm) and greater wire tension. Existing tools have a small applicable tensile limit and the applicable tensile range cannot be adjusted, making it impossible to meet the requirements for wire connection and fixation under high tension.

[0005] Therefore, in order to achieve successful separation of the wire rope from the tool string when it gets stuck in the well, and to significantly reduce the operating costs when the tool string gets stuck, it is necessary to develop a safety rope for wire rope operations in oil and gas wells. When the tool string gets stuck in the well, the wire rope can be pulled out of the rope cap by increasing the lifting force, and the pulling force can be adjusted to adapt to different types of wire rope operations. This avoids the wire rope breaking inside the well or being forced to be cut from the wellhead. After the wire rope is pulled out, normal retrieval operations can be carried out, saving manpower and resources and greatly reducing operating costs. Summary of the Invention

[0006] The purpose of this invention is to provide a safety rope cap for wireline operations in oil and gas wells. When the downhole tool string gets stuck, the wireline can be pulled out of the cap by increasing the lifting force.

[0007] Another object of the present invention is to provide a method for using a safety rope cap for wireline operations in oil and gas wells.

[0008] The technical solution adopted in this invention is a safety rope cap for steel wireline operations in oil and gas wells, including a retrieval head and a sleeve adapter. The bottom of the retrieval head is connected to the sleeve adapter. An outer conical sleeve is provided inside the retrieval head, and an inner conical sleeve is fitted inside the outer conical sleeve. Multiple upper slits are evenly distributed on the outer surface of the top of the inner conical sleeve, and multiple lower slits are evenly distributed on the outer surface of the bottom of the inner conical sleeve. The upper and lower slits are arranged alternately. A washer and a spring are provided at the top of the inner conical sleeve. One end of the spring is connected to the washer, and the other end is connected to the inner wall of the retrieval head.

[0009] The invention is further characterized in that,

[0010] The retrieval head and the adapter sleeve are connected by hexagon socket head cap screws, and an O-ring is also provided at the connection.

[0011] The head of the retrieval head is equipped with a retrieval step.

[0012] The upper slit extends from the top towards the outer surface of the inner conical sleeve, and a gap is provided between the bottom of the upper slit and the bottom of the inner conical sleeve; the lower slit extends from the bottom towards the outer surface of the inner conical sleeve, and a gap is provided between the bottom of the lower slit and the top of the inner conical sleeve.

[0013] The outer and inner tapered sleeves are tightened together by a lock nut.

[0014] A pad is also installed at the bottom of the retrieval head, located below the locking nut.

[0015] Another technical solution adopted in this invention is the method of using a safety rope cap for wireline operations in oil and gas wells, as detailed below:

[0016] S1: Connect the steel wire to the safety rope cap, and then connect it to other lifting tools in sequence through the hanging adapter of the safety rope cap;

[0017] S2: During the process of lifting the tool string to drain the liquid, the tension is used to determine whether the current load is normal. When it is higher than the maximum load value, it indicates that there is a jam and the lifting operation is stopped.

[0018] S3: Lower the tool string. If the wire tension drops rapidly to near 0, it indicates that the tool string is stuck at that point.

[0019] S4: Use a shock absorber to unlock the card;

[0020] S5: Lift at low speed. If the tension decreases, it means the jam has been successfully released. Continue lifting. If the jam cannot be released after repeated attempts, it is determined to be stuck.

[0021] S6: By increasing the tension of the steel wire, the tension reaches the rated tension that allows the safety rope cap to be pulled out, the steel wire is released from the safety rope cap, and then the steel wire is slowly pulled out of the wellhead;

[0022] S7: Replace with a dedicated retrieval tool, lower it to where the retrieval tool string gets stuck, grab the retrieval head of the safety rope cap, and further retrieve the tool string.

[0023] The beneficial effects of this invention are:

[0024] (1) The rope cap has a simple structure and is easy to use. The inner cone sleeve is designed as a cone structure with uniform slits, which can ensure that the cone can hold the steel wire under the pressing action of the cone sleeve, and ensure that the steel wire and the rope cap will not separate during normal construction.

[0025] (2) The pull-out force can be changed by adjusting the preset compression of the spring, which can meet the application requirements under different working conditions;

[0026] (3) Design a spring mechanism. When the wire gets stuck, increase the lifting force of the wire rope. After the cone compresses the spring, it moves to the left and then releases the wire, so that the wire can be released. The wire can be separated from the rope cap without the need to use other tools. This can avoid accidents such as wire breakage or forced cutting. After the wire is released, normal salvage operations can be carried out, saving manpower and resources and greatly reducing operating costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the safety rope cap for steel wire operations in oil and gas wells according to the present invention;

[0028] Figure 2 This is a schematic diagram of the inner cone sleeve in the safety rope cap for steel wire rope operations in oil and gas wells according to the present invention;

[0029] Figure 3 This is a schematic diagram of the connection of the wireline drilling tool string;

[0030] Figure 4 This invention relates to the method of using the safety rope cap for steel wire work in oil and gas wells;

[0031] Figure 5 This is a pull-out force test diagram of the safety rope cap for steel wire operations in oil and gas wells according to the present invention.

[0032] In the diagram, 1. retrieval head, 2. outer conical sleeve, 3. inner conical sleeve, 4. lock nut, 5. adapter sleeve, 6. washer, 7. pad block, 8. spring, 9. steel wire, 10. O-ring seal, 11. socket head cap screw. Detailed Implementation

[0033] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] Example 1

[0035] This invention relates to a safety rope cap for wireline work in oil and gas wells, such as... Figure 1 As shown, the tool string includes a retrieval head 1 and a sleeve adapter 5. The retrieval head 1 is connected to the bottom of the sleeve adapter 5, and the retrieval head 1 and the sleeve adapter 5 are connected by an internal hexagon head screw 11. An O-ring 10 is also provided at the connection point to prevent the tool string from falling into the well due to loosening of the threads. In addition, it can also prevent oil and water from entering the tool. The retrieval head 1 is located at the top and has a retrieval step at the head. When the tool string is stuck in the well, the tool string can be pulled out as a whole after being engaged at this step. The sleeve adapter 5 is located at the bottom and serves to connect the wire rope cap to other tool strings downhole.

[0036] The retrieval head 1 has an outer conical sleeve 2 inside, and an inner conical sleeve 3 is fitted inside the outer conical sleeve 2. The outer conical sleeve 2 and the inner conical sleeve 3 are tightened together by a locking nut 4, which serves to fix the steel wire. A pad 7 is also provided at the bottom of the retrieval head 1, located below the locking nut 4, to prevent the locking nut 4 from loosening and causing the steel wire to slip out. Figure 2 As shown, the outer surface of the top of the inner cone sleeve 3 has multiple upper slits evenly distributed, and the outer surface of the bottom of the inner cone sleeve 3 has multiple lower slits evenly distributed; the upper and lower slits are arranged alternately; the upper slits open from the top towards the outer surface of the inner cone sleeve 3, and a gap is provided between the bottom of the upper slit and the bottom of the inner cone sleeve 3; the lower slits open from the bottom towards the outer surface of the inner cone sleeve 3, and a gap is provided between the bottom of the lower slit and the top of the inner cone sleeve 3; this structure can ensure that the steel wire is held tightly and does not slip under the pressing action of the outer cone sleeve.

[0037] The inner cone sleeve 3 is equipped with a washer 6 and a spring 8 at its top. One end of the spring 8 is connected to the washer 6, and the other end is connected to the inner wall of the retrieval head 1. When the lifting force of the steel wire is increased, the inner cone sleeve 3 compresses the spring 8 and moves to the left, releasing the steel wire rope and realizing the release of the steel wire under the fixed pull-out force.

[0038] The inner cone sleeve 3 is designed as a truncated cone structure with uniform slits. Under external pressure, the truncated cone structure closes to grip the wire rope, ensuring that the cone can hold the wire rope tightly and prevent slippage under the compression of the cone sleeve. A spring mechanism is located on the left side of the cone. When the lifting force of the wire rope is increased, the cone compresses the spring and moves to the left, then releases the wire rope, achieving wire release under a fixed pull-out force. The pull-out force is adjustable to meet the needs of different working conditions.

[0039] The safety rope cap for wireline work in oil and gas wells of this invention solves the problems of existing wireline caps being fixed to the wire, causing downhole tools to get stuck in the tubing and requiring the wire to be cut, leaving the wire and tools stranded inside the wellbore, significantly increasing the difficulty and cost of retrieval. This invention can save manpower and resources and reduce operating costs. Furthermore, compared to existing safety rope caps, the ultimate pull-out force is significantly improved, allowing it to adapt to wireline work under high loads, and the pull-out force is adjustable to meet the needs of different wireline operations.

[0040] Example 2

[0041] The method of using the safety rope cap for wireline work in oil and gas wells according to the present invention is as follows: Figure 3 and 4 As shown, the details are as follows:

[0042] S1: Connect the steel wire 9 to the safety rope cap, and connect it to other lifting tools in sequence through the hanging adapter 5 of the safety rope cap;

[0043] S2: During the process of lifting the tool string to drain the liquid, the tension is used to determine whether the current load is normal. When it is higher than the maximum load value, it indicates that there is a jam and the lifting operation is stopped.

[0044] S3: Lower the tool string. If the tension of the steel wire 9 drops rapidly to near 0, it is confirmed that the tool string is stuck at that point.

[0045] S4: Use a shocker to release the jam. Pull the chain upward quickly and forcefully to make the chain shocker vibrate and release the jam. Repeat the shocking multiple times.

[0046] S5: Lift at low speed. If the tension decreases, it means the jam has been successfully released. Continue lifting. If the jam cannot be released after repeated attempts, it is determined to be stuck.

[0047] S6: By increasing the tension of steel wire 9 to the rated tension that allows the safety rope cap to be pulled out, steel wire 9 is released from the safety rope cap, and then steel wire 9 is slowly pulled out of the wellhead;

[0048] S7: Replace with a dedicated retrieval tool, lower it to the point where the retrieval tool string gets stuck, grab the retrieval head 1 of the safety rope cap, and further retrieve the tool string.

[0049] Example 3

[0050] The specific steps for using the safety rope cap for steel wireline operations in oil and gas wells according to this invention are as follows:

[0051] S1: First, tightly connect the steel wire 9 to the safety rope cap, ensuring a secure and loose connection. Next, using the safety rope cap's adapter 5, precisely connect it to various lifting tools in sequence.

[0052] S2: When performing the operation of lifting the tool string to drain the liquid, closely monitor the change in tension value to determine whether the current load is within the normal range. Once the tension exceeds the preset maximum load value, it means that jamming may have occurred, and the lifting operation must be stopped immediately.

[0053] S3: When lowering the tool string, if you notice that the tension of the steel wire 9 drops sharply and almost to 0, then you can be sure that the tool string is stuck at the current position.

[0054] S4: Use the shock absorber to attempt to release the jam. During operation, quickly and forcefully pull the chain upwards to cause the chain shock absorber to vibrate strongly, thus releasing the jam. A certain number of consecutive shocks are required, for example, 5-8 times.

[0055] S5: Lift at a low speed. If the tension decreases, it indicates that the jam has been successfully released, and you can continue lifting. However, if the jam cannot be released after repeated attempts, it is considered to be stuck.

[0056] S6: Gradually increase the tension of wire 9 until the tension reaches the rated tension that allows the safety rope cap to be pulled out. At this point, wire 9 will automatically detach from the safety rope cap, and then wire 9 will be smoothly and slowly pulled out of the wellhead.

[0057] S7: Replace with a specialized retrieval tool and carefully lower it to the position where the retrieval tool string is stuck. Accurately grasp the retrieval head 1 of the safety rope cap to further retrieve the tool string.

[0058] During on-site operations, following the above steps accurately resolved the jamming issue and successfully completed the task. At another work site, timely identification of the jamming situation and the implementation of correct countermeasures prevented equipment damage and operational delays.

[0059] Example 4

[0060] This embodiment describes the indoor performance test of a safety rope cap used in wireline work at oil and gas wells. Figure 5 As shown, the details are as follows:

[0061] Experimental steps: (1) Adjust the preset compression of the spring and set the pull-out force of the safety rope cap for oil and gas well wire rope operation to 25KN; (2) Connect the adapters to both ends of the safety rope cap for oil and gas well wire rope operation, and then fix the rope cap on the tensile testing machine; (3) Set the tensile parameters of the tensile testing machine and observe whether the wire rope is pulled out under a specific tensile force; (4) A total of 10 sets of experiments were conducted, and the test results were recorded.

[0062] The experimental results are shown in Table 1. When the tension is ≤24KN, the wire rope and the rope cap can be stably connected; when the wire rope lifting force is >26KN, the wire rope can be pulled out; the rope cap function meets the requirement of being pulled out under the expected pull-out force. Compared with existing safety rope caps, the safety rope cap for oil and gas well wireline operations of this invention has a significantly improved ultimate pull-out force, which can adapt to wireline operations under high loads, and the pull-out force is adjustable to meet the needs of different wireline operations.

[0063] Table 1. Test results of the detachable rope hat.

[0064] project Tensile force / KN Latto in conclusion Group 1 5 no qualified Group 2 10 no qualified Group 3 15 no qualified Group 4 20 no qualified Group 5 22 no qualified Group 6 24 no qualified Group 7 26 yes qualified Group 8 28 yes qualified Group 9 30 yes qualified Group 10 35 yes qualified

Claims

1. A safety rope cap for wireline work in oil and gas wells, characterized in that, The device includes a retrieval head (1) and a sleeve adapter (5). The bottom of the retrieval head (1) is connected to the sleeve adapter (5). An outer conical sleeve (2) is provided inside the retrieval head (1). An inner conical sleeve (3) is fitted inside the outer conical sleeve (2). Multiple upper slits are evenly distributed on the outer surface of the top of the inner conical sleeve (3). Multiple lower slits are evenly distributed on the outer surface of the bottom of the inner conical sleeve (3). The upper and lower slits are arranged alternately. A gasket (6) and a spring (8) are provided at the top of the inner conical sleeve (3). One end of the spring (8) is connected to the gasket (6), and the other end is connected to the inner wall of the retrieval head (1).

2. The safety rope cap for steel wire work in oil and gas wells as described in claim 1, characterized in that, The retrieval head (1) and the sleeve adapter (5) are connected by an internal hexagonal head screw (11), and an O-ring (10) is also provided at the connection.

3. The safety rope cap for steel wire work in oil and gas wells as described in claim 1, characterized in that, The head of the salvage head (1) is provided with a salvage step.

4. The safety rope cap for steel wire work in oil and gas wells as described in claim 1, characterized in that, The upper slit is opened along the top towards the outer surface of the inner conical sleeve (3), and a gap is provided between the bottom of the upper slit and the bottom of the inner conical sleeve (3); the lower slit is opened along the bottom towards the outer surface of the inner conical sleeve (3), and a gap is provided between the bottom of the lower slit and the top of the inner conical sleeve (3).

5. The safety rope cap for steel wire work in oil and gas wells as described in claim 1, characterized in that, The outer cone sleeve (2) and the inner cone sleeve (3) are pressed together by a locking nut (4).

6. The safety rope cap for steel wire work in oil and gas wells as described in claim 5, characterized in that, A pad (7) is also provided at the bottom of the retrieval head (1), and the pad (7) is located below the locking nut (4).

7. The method of using the safety rope cap for wireline work in oil and gas wells as described in any one of claims 1-6, characterized in that, Specifically as follows: S1: Connect the steel wire to the safety rope cap, and then connect it to other lifting tools in sequence through the hanging adapter of the safety rope cap; S2: During the process of lifting the tool string to drain the liquid, the tension is used to determine whether the current load is normal. When it is higher than the maximum load value, it indicates that there is a jam and the lifting operation is stopped. S3: Lower the tool string. If the wire tension drops rapidly to near 0, it indicates that the tool string is stuck at that point. S4: Use a shock absorber to unlock the card; S5: Lift at low speed. If the tension decreases, it means the jam has been successfully released. Continue lifting. If the jam cannot be released after repeated attempts, it is determined to be stuck. S6: By increasing the tension of the steel wire, the tension reaches the rated tension that allows the safety rope cap to be pulled out, the steel wire is released from the safety rope cap, and then the steel wire is slowly pulled out of the wellhead; S7: Replace with a dedicated retrieval tool, lower it to where the retrieval tool string gets stuck, grab the retrieval head of the safety rope cap, and further retrieve the tool string.

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