Injection well containment fishing wellhead device

Abstract

The present application relates to the well logging fishing is used closed fishing device, especially relates to a kind of injection well closed fishing wellhead device.The device includes wellhead sealing locking gate, variable-diameter positioning fishing short circuit and hydraulic sealing short circuit;Wellhead sealing locking gate includes main body, sealing clamping elastic gate, gate hand wheel;The upper end of main body is connected to blowout preventer, and its lower end is connected to hydraulic sealing short circuit;Variable-diameter positioning fishing short circuit includes heavy rod connector, variable-diameter positioning short circuit, fishing head;Heavy rod connector connects variable-diameter positioning short circuit;Variable-diameter positioning short circuit can be detachably connected to fishing head;Hydraulic sealing short circuit includes: steel sleeve, rubber tube, pressurizing connector, first piston, second piston and spring;Injection well closed fishing wellhead device provided by the present application maximizes the success rate of fishing, meets the requirements of safety and environmental protection standards, realizes the goal of zero overflow and zero pollution on site.

Description

Technical Field

[0001] This invention relates to a closed retrieval device used in well logging and retrieval, and particularly to a closed retrieval device for injection wellheads. Background Technology

[0002] Conventional fishing operations typically employ two methods: open-loop fishing with pressure release and closed-loop fishing. However, with increasingly stringent environmental protection requirements for well logging operations in recent years, the open-loop method often fails to meet safety and environmental requirements. Therefore, closed-loop fishing is the only viable option in well logging operations. However, closed-loop fishing presents the following two problems during operation:

[0003] (1) Due to the height of the blowout preventer, when the total length of the retrieval instrument string and retrieval device exceeds the length of the blowout preventer, the entire string of devices cannot be successfully retrieved from the wellhead.

[0004] (2) For high-pressure injection wells, the fishing device needs to be equipped with a sufficient number of weights, which will inevitably increase the overall length of the fishing device and make it more difficult to lift the instrument out of the wellhead. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] This invention provides a sealed wellhead retrieval device for injection wells to overcome the shortcomings of existing technologies, such as numerous obstacles and low success rates during the retrieval process.

[0007] (II) Technical Solution

[0008] To solve the above problems, the present invention provides a sealed wellhead retrieval device for injection wells, characterized in that it comprises:

[0009] Wellhead sealing and locking gate, variable diameter positioning and fishing short-connector, and hydraulic well sealing short-connector;

[0010] The wellhead sealing and locking gate includes a main body, a sealing and clamping elastic gate plate, and a gate handwheel;

[0011] The upper end of the main body is connected to a blowout preventer, and the lower end is connected to a hydraulic well sealing connector;

[0012] The sealing clamping elastic gate is U-shaped and is located in the cavity of the main body. The two ends of the main body are respectively connected to the gate handwheel. By rotating the gate handwheel, the sealing clamping elastic gate undergoes elastic deformation, which plays a locking and clamping role in the variable diameter positioning short-connection in the variable diameter positioning salvage short-connection.

[0013] The variable diameter positioning and retrieval short connector is installed in the main body of the wellhead sealing and locking gate; the variable diameter positioning and retrieval short connector includes: a weighted rod connector, a variable diameter positioning short connector, and a retrieval head;

[0014] The weighted rod connector is connected to a variable diameter positioning short circuit; the variable diameter positioning short circuit is detachably connected to the retrieval head;

[0015] The upper part of the hydraulic well sealing short-connector is connected to the wellhead sealing and locking gate, and the lower part is connected to the wellhead;

[0016] The hydraulic well-sealing short connector includes: a steel sleeve, a rubber sleeve, a pressure fitting, a first piston, a second piston, and a spring; the rubber sleeve is disposed in the steel sleeve, and the pressure fitting is connected to one side of the steel sleeve and communicates with the inner cavity of the hydraulic well-sealing short connector; the spring is sleeved on the second piston, and hydraulic oil enters the inner cavity of the hydraulic well-sealing short connector through the pressure fitting, pushing the piston upward to squeeze the rubber sleeve, causing the rubber sleeve to deform and change diameter to position and seal the retrieval head in the short connector.

[0017] Preferably, the sealing clamping elastic gate is made of rubber material.

[0018] Preferably, the diameter of the variable diameter positioning short circuit is smaller than the diameter of the weighted rod connector.

[0019] Preferably, the diameter of the variable-diameter positioning short circuit is smaller than the diameter of the retrieval head.

[0020] Preferably, the upper end of the wellhead sealing and locking gate is connected to a blowout preventer, and the lower end is connected to a hydraulic well sealing short connector.

[0021] (III) Beneficial Effects

[0022] The injection well sealing and retrieval device provided by this invention achieves a double-stage sealing effect by setting a wellhead sealing and locking gate and a hydraulic well sealing short circuit, which enhances the environmental friendliness of the device, maximizes the retrieval success rate, meets the requirements of safety and environmental protection standards, and achieves the goal of zero overflow and zero pollution on site. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the sealed wellhead retrieval device for injection wells according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the variable diameter positioning and retrieval short-connection structure in the sealed retrieval wellhead device of the injection well according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the wellhead sealing and locking gate structure in the wellhead sealing and retrieval device of the injection well according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the hydraulic well-sealing short-connection structure in the wellhead sealing and retrieval device of the injection well according to an embodiment of the present invention.

[0027] The components include: 1. Wellhead sealing and locking gate; 2. Variable diameter positioning and retrieval short connector; 3. Variable diameter positioning and retrieval short connector; 11. Main body; 12. Sealing clamping elastic gate plate; 13. Gate handwheel; 21. Weight rod connector; 22. Variable diameter positioning short connector; 23. Retrieval head; 24. Instrument string; 31. Steel sleeve; 32. Rubber sleeve; 33. Pressure joint; 34. First piston; 35. Second piston; 36. Spring. Detailed Implementation

[0028] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0029] like Figure 1 As shown, the present invention provides a sealed wellhead retrieval device for injection wells, comprising: a wellhead sealing and locking gate 1, a variable diameter positioning retrieval short connector 2, and a variable diameter positioning retrieval short connector;

[0030] The wellhead sealing and locking gate 1 includes a main body 11, a sealing and clamping elastic gate plate 12, and a gate handwheel 13;

[0031] The upper end of the main body 11 is connected to a blowout preventer, and the lower end is connected to a hydraulic well sealing short connector 3;

[0032] The sealing clamping elastic gate 12 is U-shaped and is located in the cavity of the main body 11. The two ends of the main body 11 are respectively connected to the gate handwheel 13. By rotating the gate handwheel 13, the sealing clamping elastic gate 12 undergoes elastic deformation, which plays a locking and clamping role in the diameter positioning short-connection in the diameter positioning retrieval short-connection. The sealing clamping elastic gate 12 is made of elastic material, such as rubber.

[0033] The wellhead sealing and locking gate 1 is connected to a blowout preventer at the upper end and a hydraulic well-sealing connector at the lower end. Its main function is to lock and clamp the variable diameter positioning connector 22 in the variable diameter positioning retrieval connector after successful retrieval. At the same time, the sealing clamping elastic gate 12 provides a certain sealing effect. By calculating the length of the retrieval weight rod and the retrieval connector, when the cable is slowly raised at the wellhead until it encounters a jam, the variable diameter section is exactly aligned with the sealing clamping elastic gate 12 of the locking gate. At this time, the gate handwheel is turned to advance the sealing clamping elastic gate 12 to clamp the variable diameter positioning connector 22, and the first stage of clamping and sealing is completed.

[0034] The variable diameter positioning and retrieval short connector 2 is installed in the main body of the wellhead sealing and locking gate 1; the variable diameter positioning and retrieval short connector 2 includes: a weight rod connector 21, a variable diameter positioning short connector 22, and a retrieval head 23;

[0035] The weighted rod connector 21 is connected to the variable diameter positioning short connector 22; the variable diameter positioning short connector 22 is detachably connected to the retrieval head 23, which is used to retrieve the instrument string 24 that has fallen into the well.

[0036] The diameter of the variable diameter positioning short connector 22 is smaller than the diameter of the weighted rod connector 21, and the diameter of the variable diameter positioning short connector 22 is smaller than the diameter of the retrieval head 23.

[0037] In practical applications, the weighted rod connector 21 adopts a φ31 weighted rod connector; the variable diameter positioning short connector 22 adopts a φ28 variable diameter positioning short connector.

[0038] The variable-diameter positioning and retrieval short connector with the above structure, together with the wellhead sealing and locking gate, plays the role of clamping, sealing and limiting. The lower end is a conventional retrieval head, which can be replaced according to the different objects falling into the well.

[0039] The upper part of the hydraulic well sealing short-connector 3 is connected to the wellhead sealing and locking gate 1, and the lower part is connected to the wellhead;

[0040] The hydraulic well-sealing short connector 3 includes: a steel sleeve 31, a rubber sleeve 32, a pressure connector 33, a first piston 34, a second piston 35, and a spring 36. The rubber sleeve 32 is disposed within the steel sleeve 31, and the pressure connector 33 is connected to one side of the steel sleeve 31 and communicates with the inner cavity of the hydraulic well-sealing short connector. The spring 36 is fitted onto the second piston 35. Hydraulic oil enters the inner cavity between the first piston 34 and the second piston 35 of the hydraulic well-sealing short connector through the pressure connector, pushing the first piston 34 upward to squeeze the rubber sleeve 32. The rubber sleeve 32 deforms, sealing the retrieval head 23 in the variable-diameter positioning retrieval short connector. The second piston 35, under the action of the spring 36, pushes the hydraulic oil in the inner cavity out of the hydraulic well-sealing short connector when the pressure is released after retrieval is completed.

[0041] After completing the double-stage sealing and locking, the blowout preventer above the wellhead sealing and locking gate can be removed. After removing the retrieval weight, use the retrieval cable head to directly connect the reducing diameter positioning retrieval short connector. After reinstalling the wellhead blowout preventer, sequentially open the hydraulic sealing short connector and the wellhead sealing and locking gate, and lift the retrieval instrument string into the blowout preventer. Close the wellhead gate of the production tree to complete the retrieval operation.

[0042] The wellhead sealing and locking gate 12 is connected to a blowout preventer at the upper end and a hydraulic well sealing short-circuit 3 at the lower end.

[0043] During use, the wellhead sealing and locking gate 12 is connected to the blowout preventer (BOP). The upper part of the hydraulic sealing connector is connected to the wellhead sealing and locking gate 12, and the lower part is connected to the wellhead. During retrieval, the variable diameter positioning retrieval connector is connected to the weight rod and the retrieval cable head, and then lowered into the wellbore through the BOP and wellhead device. The sealing and locking gate uses the sealing clamping elastic gate 12 to clamp and seal the variable diameter positioning retrieval connector after retrieval. The hydraulic sealing connector seals the part below the retrieval head through the hydraulic sealing rubber sleeve, achieving a double-stage pressure reduction and sealing effect. This allows the retrieval device to retrieve the downhole instrument string in stages, ensuring a completely sealed retrieval process with no overflow.

[0044] The following describes the working process of the injection well sealing and retrieval wellhead device:

[0045] 1. Install the wellhead sealing and locking gate and the hydraulic well sealing short connector on the wellhead test gate. Connect the blowout preventer above the wellhead sealing and locking gate. Then connect the variable diameter positioning and retrieval short connector to the retrieval cable head and the lower part of the weight rod. Lower the connector into the wellbore through the blowout preventer and the wellhead device.

[0046] 2. After the salvage operation is completed, the entire set of equipment is lifted into the blowout preventer. At this time, the salvage equipment and its weight rod are inside the blowout preventer, while the instrument string remains in the wellbore.

[0047] 3. Close the sealing gates on both sides of the wellhead sealing and locking gate, and use the rubber gate head to seal and clamp the variable diameter positioning and retrieval short connector and the instrument string below it. Pressurize the hydraulic sealing short connector. At this time, the part below the hydraulic sealing short connector is sealed, and the object in the pipe is locked to prevent it from falling.

[0048] 4. After removing the blowout preventer, remove the cable head and weight bar at the top of the variable diameter positioning retrieval connector; connect the cable head and the variable diameter positioning retrieval connector, erect the blowout preventer, open the wellhead sealing lock gate, depressurize the hydraulic well sealing connector, and then retrieve the remaining retrieval head and instrument string to complete the retrieval operation.

[0049] This invention has the following characteristics:

[0050] (1) The variable diameter positioning and retrieval short connector is designed to be disassembled after being lifted to the wellhead and is located between the blowout preventer and the wellhead sealing and locking gate. The weighting equipment and cable head can be removed and replaced in a vertical state.

[0051] (2) A wellhead sealing and locking gate is used in conjunction with the variable diameter positioning and retrieval short connection. The elasticity of the rubber is used to seal and clamp the part below the retrieval head, thereby achieving the purpose of sealing.

[0052] (3) The hydraulic well sealing short circuit is designed to achieve the effect of double-stage sealing, which enhances the environmental protection of the device.

[0053] Two sets of this device are currently being manufactured and equipped by two injection profile logging teams. In 2020, it was used for 9 well retrieval operations with a success rate exceeding 98%, saving over 17 times the cost of hiring tank trucks. Nine instruments and 31 weighted rods were retrieved, and zero overflow was achieved at the retrieval site. Additionally, it saved the oilfield 5 operation costs for 5 wells where pressure could not be vented. This equipment is suitable for the closed-loop retrieval process of downhole objects during injection profile operations. It is expected that within the next 3-5 years, this system can be extended to all production teams of the Testing Technology Service Branch for downhole object retrieval operations. This will save on tank truck hiring costs during retrieval operations, eliminate potential pollution during the retrieval process, and meet safety and environmental protection standards while ensuring a high success rate, achieving zero overflow and zero pollution at the site.

[0054] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the patent protection scope of the present invention should be defined by the claims.

Claims

1. A sealed wellhead retrieval device for injection wells, characterized in that, include: Wellhead sealing and locking gate, variable diameter positioning and fishing short-connector, and hydraulic well sealing short-connector; The wellhead sealing and locking gate includes a main body, a sealing and clamping elastic gate plate, and a gate handwheel; The upper end of the main body is connected to a blowout preventer, and the lower end is connected to a hydraulic well sealing connector; The sealing clamping elastic gate is U-shaped and is located in the cavity of the main body. The two ends of the main body are respectively connected to the gate handwheel. By rotating the gate handwheel, the sealing clamping elastic gate undergoes elastic deformation, which plays a locking and clamping role in the variable diameter positioning short-connection in the variable diameter positioning salvage short-connection. The variable diameter positioning and retrieval short connector is installed in the main body of the wellhead sealing and locking gate; the variable diameter positioning and retrieval short connector includes: a weighted rod connector, a variable diameter positioning short connector, and a retrieval head; The weighted rod connector is connected to a diameter-changing positioning short circuit; the diameter-changing positioning short circuit is detachably connected to the retrieval head. The upper part of the hydraulic well sealing short-connector is connected to the wellhead sealing and locking gate, and the lower part is connected to the wellhead; The hydraulic well sealing connector includes: a steel sleeve, a rubber sleeve, a pressure fitting, a first piston, a second piston, and a spring; The rubber sleeve is housed within a steel sleeve, and the pressure fitting is connected to one side of the steel sleeve and communicates with the inner cavity of the hydraulic well sealing short connector. A spring is fitted onto the second piston, and hydraulic oil enters the inner cavity between the first and second pistons of the hydraulic well sealing short connector through the pressure fitting, pushing the first piston upward to squeeze the rubber sleeve. The rubber sleeve deforms, sealing the retrieval head in the variable diameter positioning retrieval short connector. The second piston is used to push the hydraulic oil in the inner cavity out of the hydraulic well sealing short connector under the action of the spring when the pressure is released after retrieval is completed.

2. The sealed wellhead retrieval device for injection wells as described in claim 1, characterized in that, The sealing clamping elastic gate is made of rubber material.

3. The sealed wellhead retrieval device for injection wells as described in claim 1, characterized in that, The diameter of the variable diameter positioning short circuit is smaller than the diameter of the weighted rod connector.

4. The sealed wellhead retrieval device for injection wells as described in claim 1, characterized in that, The diameter of the variable-diameter positioning short circuit is smaller than the diameter of the retrieval head.

Images