Device and process for on-line replacement of main valve of water injection well

Abstract

The invention discloses a device and process for replacing a main valve of a water injection well on line, and belongs to the technical field of petroleum and natural gas development, the device comprises a slip support, a blowout preventer and a blanking plug, the slip support is fixed on a large four-way flange of a wellhead of the water injection well, four support pull rods are connected to the slip support, and a fixing plate for placing a hydraulic cylinder is arranged on the upper portions of the support pull rods; the lower portion of a hydraulic cylinder ejector rod of the hydraulic cylinder is connected with a blanking plug through a connector, and a blowout preventer is fixedly arranged on the hydraulic cylinder ejector rod. The hydraulic station is used for operating the hydraulic cylinder, so that the soft interference blanking plug in the water injection tubular column can quickly enter a designated position to seal high-pressure liquid in the water injection tubular column, sealing is reliable, operation time is shortened, working efficiency and safety are obviously improved, and the device has the advantages of being simple and compact in structure and convenient to install.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and natural gas development, and in particular relates to a device and a process for replacing a main valve online in a water injection well. Background Art

[0002] After a long period of production, many problems will occur in the wellhead control valves of water injection wells, such as rust and jamming, aging of seals, wear and leakage of seals, etc., which seriously affect the production of water injection wells. Once out of control, the consequences are quite serious. Not only will it cause environmental pollution accidents, but it will also affect the testing and debugging of water injection wells, resulting in substandard water injection and affecting the production of oil wells. Therefore, a device and method for replacing valves under pressure in water injection wells is needed. Conventional processes use valve replacement after well pressure reduction, which will cause serious interference to the normal production of water injection wells and bring the following unfavorable factors:

[0003] a) The killing fluid will cause certain damage to the oil layer, and it may even be impossible to resume production;

[0004] b) Upgrading operations require a large amount of funds;

[0005] c) It requires a lot of preparation work and the use of various equipment, a long construction period, and untimely disposal;

[0006] d) The discharge of well-killing fluid will cause serious pollution.

[0007] The tools used in the market include simple valve repair tools, which use the tools to hold the valve screw to repair the valve, but lack effective blocking of the pressure channel, which leads to high risks during the operation. Or the tools used are bulky, the equipment is inconvenient to operate, the efficiency is relatively low, and there are more operations than procedures by on-site personnel. Summary of the invention

[0008] In order to solve the above-mentioned problems, the present invention proposes: a device for replacing the main valve online in an injection well, comprising a slip support, a blowout preventer and a plug, the slip support is fixed on a large four-way flange at the wellhead of the injection well, four support tie rods are connected to the slip support, a fixing plate for placing a hydraulic cylinder is arranged on the upper part of the support tie rod, the lower part of the hydraulic cylinder top rod of the hydraulic cylinder is connected to the plug through a connecting joint, and a blowout preventer is fixedly arranged on the hydraulic cylinder top rod.

[0009] Further, the blowout preventer is fixed to the wellhead test valve through slips.

[0010] Furthermore, the blowout preventer comprises a cylinder, a pressure cap and a pressure plate, a pressure plate is arranged above the cylinder, and the pressure cap is buckled on the pressure plate and connected to the cylinder.

[0011] A process for replacing the main valve of a water injection well online, wherein the main water injection valve is opened to the maximum, and a blowout preventer is mounted on the plug.

[0012] Further, the plugging device and the hydraulic cylinder top rod are connected by a connecting joint, and the hydraulic cylinder top rod is moved downward to fix the blowout preventer and the wellhead test valve with slips.

[0013] Further, the test valve is opened, and the plug is lowered to a suitable position by moving the hydraulic push rod downward to isolate the downhole pressure.

[0014] Furthermore, remove the upper and lower slips of the main water injection valve, lift the upper wellhead upward with a jack, fix the plug on the large four-way valve with half a clip and slips, remove the hydraulic cylinder push rod and connecting joints, retract the hydraulic cylinder push rod, remove the main water injection valve and replace it with a new valve.

[0015] Further, lower the hydraulic cylinder top rod, connect the hydraulic cylinder top rod, the connecting joint and the plug in sequence, remove the slips and half of the clip, install the new valve with the slips, withdraw the hydraulic cylinder top rod, and the disassembly tool operation is completed.

[0016] The beneficial effects of the present invention are as follows: in view of the problem that the failure of the main valve of the water injection well affects the implementation of the overall water injection development plan of the oil field and thus affects the crude oil production, the hydraulic station is used to operate the hydraulic cylinder to quickly realize the soft interference plug in the water injection pipe column to enter the designated position, seal the high-pressure liquid in the water injection pipe column, seal reliably, shorten the operation time, and significantly improve the work efficiency and safety. It has the characteristics of simple and compact structure, easy installation, safety and controllability.

[0017] The invention has the following beneficial technical effects:

[0018] 1. The main water injection valve can be replaced without pressure relief, which solves the problem of replacing the main valve of the high-pressure water injection well after it is damaged, and ensures the normal water injection of the water injection well.

[0019] 2. The present invention can quickly realize the plugging device entering the designated position by operating the hydraulic cylinder through the hydraulic station. The operation of the on-site personnel is simple, the plugging device is operated and sealed reliably, the operation time is shortened, and the work efficiency and safety are significantly improved. The problem that the up-repair operation needs to consume a lot of funds is solved, and the construction cost of replacing the valve is reduced.

[0020] 3. Safe and environmentally friendly, it has the characteristics of simple and compact structure and easy installation. The tool installation can be completed on site without large equipment, so that the construction work can be completed quickly. It solves the problem that the original method requires a lot of preparation work and the use of various equipment, and the long construction period causes environmental pollution.

[0021] 4. Good sealing, strong practicality, and quick emergency response. It solves the problem that large construction vehicles cannot enter the construction site due to road problems in the rainy season. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1This is a structural schematic diagram of an online replacement main valve device for a water injection well according to the present invention;

[0023] Figure 2 It is a structural schematic diagram of the blowout preventer of the present invention;

[0024] Figure 3 It is a structural schematic diagram of a half-piece clip of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the plug of the present invention;

[0026] Figure 5 It is a structural schematic diagram of the slip support of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the connection joint of the present invention;

[0028] Figure 7 It is a structural schematic diagram of the water injection well of the present invention.

[0029] Wherein, the accompanying drawings are marked as follows:

[0030] 1. Slip support, 2. Support rod, 3. Fixed plate, 4. Blowout preventer, 5. Connecting joint, 6. Plug, 7. Hydraulic cylinder push rod, 8. Half clip, 9. Hydraulic cylinder, 10. Cylinder, 11. Pressure plate, 12. Pressure cap, 13. Large four-way flange, 14. Wellhead test valve, 15. Main water injection valve. DETAILED DESCRIPTION

[0031] In order to make the technical means and objectives of the present invention easy to understand, the present invention is further described below in combination with specific embodiments. A device for replacing the main valve of a water injection well online, such as Figure 1 , Figure 7 As shown, the slip support 1 ( Figure 5 ) is fixed on the large four-way flange 13 at the wellhead of the injection well. Four support rods 2 are connected to the slip support 1. The upper part of the support rod 2 is a fixed plate 3 connected to the hydraulic cylinder 9. The blowout preventer 4 ( Figure 2 ) and the wellhead test valve 14 are fixed with slips. The blowout preventer 4 is composed of a cylinder 10, a pressure cap 12, and a pressure plate 11. The lower part of the hydraulic cylinder top rod 7 is connected to the joint 5 ( Figure 6 ) and plug 6 ( Figure 4 ).

[0032] A process for replacing the main valve of a water injection well online, the working method of which is to open the main water injection valve 15 to the maximum, and put the blowout preventer 4 on the plug 6. Use the connecting joint 5 to connect the plug 6 and the hydraulic cylinder push rod 7, and use the hydraulic cylinder push rod 7 to move downward to fix the blowout preventer 4 and the wellhead test valve 14 with slips. Open the test valve 14, and use the hydraulic push rod 7 to move downward to lower the plug 6 to a suitable position to isolate the downhole pressure.

[0033] Remove the upper and lower slips of the main water injection valve 15, lift the upper wellhead upward with a jack, and remove the plug 6 with a half clip 8 ( Figure 3 ) and slips are fixed on the large four-way valve, disassemble the hydraulic cylinder push rod 7 and the connecting joint 5, retract the hydraulic push rod 7, remove the main water injection valve 15 and replace it with a new valve. Lower the hydraulic push rod 7, connect the hydraulic cylinder push rod 7, the connecting joint 5 and the plug 6, remove the slips and half of the clip 8, install the new valve with the slips, withdraw the hydraulic push rod 7, and the removal tool operation is completed. Special note: When replacing the main water injection valve, this device does not need to disassemble other wellhead parts, and the main water injection valve can be directly replaced.

[0034] Its working principle is to use the hydraulic cylinder push rod to move downward to lower the plug to the appropriate position and isolate the downhole pressure. At this time, remove the upper and lower slips of the water injection main valve, use a jack to lift the upper wellhead upward, fix the plug on the large four-way with a half-piece clip and slips, disassemble the push rod joint, retract the hydraulic push rod, remove the main valve and replace it with a new valve. Lower the hydraulic push rod, connect the push rod joint and the plug, remove the slips and half a piece of clips, install the new valve with slips, withdraw the hydraulic push rod, and the disassembly tool operation is completed.

[0035] The core component of the present invention is a soft interference water injection pipe column plug 6 ( Figure 4 ), using rubber vulcanization molding, its outer diameter is larger than the inner diameter of the water injection column, using the compressible properties of the rubber body, using a high-pressure hydraulic station to push ( Figure 1 ) hydraulic cylinder push rod 7, put the plug 6 into the water injection column, and then use half a piece of clip ( Figure 3 ) Disconnect the slips and lock the connecting rod connected to the soft interference fit plug 6 to control the liquid in the injection pipe string at the wellhead of the injection well, creating conditions for replacing the faulty main valve in the next step.

[0036] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for replacing the main valve online in a water injection well. It is characterized in that The invention comprises a slip support (1), a blowout preventer (4) and a plug (6); the slip support (1) is fixed on a large four-way flange (13) at the wellhead of a water injection well; four support tie rods (2) are connected to the slip support (1); a fixing plate (3) for placing a hydraulic cylinder (9) is arranged on the upper part of the support tie rod (2); the lower part of a hydraulic cylinder top rod (7) of the hydraulic cylinder (9) is connected to the plug (6) via a connecting joint (5); and the blowout preventer (4) is fixedly arranged on the hydraulic cylinder top rod (7).

2. The device for replacing the main valve of a water injection well online as claimed in claim 1, It is characterized in that The blowout preventer (4) is fixed to the wellhead test valve (14) via slips.

3. The device for replacing the main valve of a water injection well online as claimed in claim 2, It is characterized in that The blowout preventer (4) comprises a cylinder (10), a pressure cap (12) and a pressure plate (11). The pressure plate (11) is arranged above the cylinder (10), and the pressure cap (12) is buckled on the pressure plate (11) and connected to the cylinder (10).

4. A process for replacing the main valve of a water injection well online. It is characterized in that The main water injection valve (15) is opened to the maximum, and a blowout preventer (4) is mounted on the plug (6).

5. The process for replacing the main valve of the water injection well online as claimed in claim 4, It is characterized in that The plug (6) and the hydraulic cylinder top rod (7) are connected by a connecting joint (5), and the hydraulic cylinder top rod (7) is moved downward to fix the blowout preventer (4) and the wellhead test valve (14) by means of slips.

6. The process for replacing the main valve of a water injection well online as claimed in claim 5, It is characterized in that The test valve (14) is opened, and the plug (6) is lowered to a suitable position by moving the hydraulic push rod (7) downward to isolate the downhole pressure.

7. The process for replacing the main valve of a water injection well online as claimed in claim 6, It is characterized in that Remove the upper and lower slips of the water injection main valve (15), lift the upper wellhead upward with a jack, fix the plug (6) on the large four-way valve with a half clip (8) and slips, disassemble the hydraulic cylinder push rod (7) and the connecting joint (5), retract the hydraulic cylinder push rod (7), remove the water injection main valve (15) and replace it with a new valve.

8. The process for replacing the main valve of a water injection well online as claimed in claim 7, It is characterized in that Lower the hydraulic cylinder top rod (7), connect the hydraulic cylinder top rod (7), the connecting joint (5) and the plug (6) in sequence, remove the slips and the half clip (8), install the new valve with the slips, withdraw the hydraulic cylinder top rod (7), and the disassembly tool operation is completed.

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