Cable-controlled safety release device for oil and gas wells

Abstract

The present invention relates to the field of cable-transmitted bridge plugs, perforating and logging technologies for unconventional oil and gas wells, and is specifically a cable-controlled safety release device for oil and gas wells; it includes an upper joint, a salvage cap, and a lower joint, and the salvage cap is threadedly connected to the lower joint, and is characterized in that it also includes an upper shell, an intermediate joint, a lower shell, an electric motor, a striker, a thimble, a release claw, a locking ring, and a locking ring fixing pin; the cable-controlled safety release device can replace the weak point of the cable head, and the salvage cap is exposed after release, which is easy for subsequent continuous tubing salvage. It has the characteristics of high safety and reliability, easy implementation, and low manufacturing cost.

Description

Technical Field

[0001] The invention relates to the technical field of cable-transmitted bridge plugs, perforating and well logging for unconventional oil and gas wells, and in particular to a cable-controlled safety release device for oil and gas wells. Background Art

[0002] With the rapid development of unconventional natural gas, the world's energy landscape is changing and becoming a global hotspot. Unconventional natural gas generally refers to natural gas resources whose geological conditions and mining conditions are different from those of conventional natural gas, and which cannot be economically produced by conventional mining methods, mainly including tight gas, coalbed methane, shale gas, etc. In recent years, through the continuous research and development and improvement of related technologies at home and abroad, a mature and complete cable pumping bridge plug cluster perforation and staged fracturing technology has been formed, which has enabled the huge release of oil and gas that was difficult to use in the past.

[0003] At present, domestic unconventional oil and gas production will complete hundreds of wells and thousands of bridge plugging, perforating and logging construction tasks every year, but most of these wells are horizontal wells. The fastest and most effective way of transportation is cable transportation and hydraulic pumping. In order to protect the safety of the cable, prevent the cable from being pulled off from the middle or wellhead and falling into the well, and reduce the difficulty of salvage, the current common practice of domestic companies is to set weaknesses in the cable head. However, this practice makes the cable head low in strength and easy to break off during pumping or perforation explosion. Every year, at least dozens of cable jams and perforation explosion breaks or pumping accidents occur in China, which not only delays the construction progress, but also invests a lot of manpower, material and financial resources in subsequent salvage. Therefore, designing a cable control safety release device at the cable head to replace physical weaknesses and improve the strength of the cable head should be put on the research and development application agenda. Summary of the invention

[0004] The present invention aims at the problems existing in the prior art and provides an oil and gas well cable controlled safety release device.

[0005] The technical solution is as follows:

[0006] A cable-controlled safety release device for oil and gas wells comprises an upper joint, a salvage cap and a lower joint, wherein the salvage cap is threadedly connected to the lower joint, and further comprises an upper shell, an intermediate joint, a lower shell, an electric motor, a striker, an ejector pin, a release claw, a locking ring and a locking ring fixing pin; the upper shell is sleeved with the intermediate joint, and the intermediate joint is slidably sleeved with the lower shell; the intermediate joint is provided with a channel A connecting the upper and lower shells; the electric motor is arranged in the upper shell and is connected to the striker through a reducer drive; the striker is slidably inserted in the channel A and is linked with the ejector pin; the root of the release claw is fixedly arranged on the intermediate joint, and the claw portion is clamped on the lower joint; the locking ring is slidably sleeved on the claw portion and is locked with the claw portion; the locking ring fixing pin is fixedly connected to the locking ring; the ejector pin is linked with the locking ring fixing pin.

[0007] Furthermore, a control circuit module is also provided in the upper shell, and the electric motor is connected to the upper single core plug through the control circuit module, and the control circuit module includes a telemetry communication circuit, an electric motor drive circuit and a voltage protection circuit. It also includes a salvage cap, a release claw is clamped on the salvage cap, and the salvage cap is threadedly connected to the lower joint. It also includes a shock-absorbing block, which is arranged between the control circuit module and the inner wall of the upper shell.

[0008] Furthermore, it also includes a shock absorber, which is wrapped around the electric motor. A sealing ring is provided between the upper shell and the middle joint. One end of the lower joint is provided with an internal thread, and one end of the salvage cap is provided with an external thread, and the salvage cap and the lower joint are threadedly connected. A hole B is provided in the salvage cap, and at least two axial through grooves are axially provided at the lower end of the salvage cap; the locking and fixing pin passes through the axial barrel groove, and the two ends are fixedly connected to the locking ring; the ejector pin is slidably inserted into the hole B, and the lower end is placed on the locking and fixing pin. The release claw is provided with a plurality of claws in pairs. There are four claws.

[0009] The beneficial effects of the present invention are:

[0010] The cable head weakness can be replaced by a cable-controlled safety release device, which exposes the salvage cap after release, making it easy to salvage the subsequent coiled tubing. It has the characteristics of high safety and reliability, easy implementation and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the present invention;

[0012] In the figure: upper connector 1, control circuit module 2, electric motor 3, reducer 4, intermediate joint 5, release claw 6, ejector pin 7, locking ring 8, lower single-core plug 9, upper single-core plug 10, shock-absorbing block 11, upper shell 12, shock-absorbing assembly 13, striker 14, lower shell 15, salvage cap assembly 16, locking ring fixing pin 17, anti-rotation ejector screw 18, lower connector 19, channel A 20, channel B 21. DETAILED DESCRIPTION

[0013] See also Figure 1 The oil and gas well cable control safety release device consists of an upper connector 1, a control circuit module 2, an electric motor 3, a reducer 4, an intermediate joint 5, a release claw 6, a thimble 7, a locking ring 8, a lower single-core plug 9, an upper single-core plug 10, a shock-absorbing block 11, an upper shell 12, a shock-absorbing assembly 13, a striker 14, a lower shell 15, a salvage cap assembly 16, a locking ring fixing pin 17, an anti-rotation thimble 18, and a lower connector 19.

[0014] The upper shell, the middle joint, the lower shell and the lower joint are cylindrical short-circuited.

[0015] The upper end of the upper shell is an upper joint, in which an upper single-core plug mounting hole is provided, in which the upper single-core plug is inserted, and below the upper joint is a space for installing electrical components; an intermediate joint is sleeved at the bottom of the upper shell, and a channel A axially penetrating the intermediate joint is provided in the center of the intermediate joint for inserting a striker; a lower shell is slidably sleeved below the intermediate joint, and inside the lower shell is a space for installing components such as an ejector pin and a salvage cap; a lower joint is sleeved at the bottom of the lower shell.

[0016] The upper end of the upper connector 1 is provided with an external thread, which is directly connected to the cable head assembly, and an upper single core plug 10 is provided inside for isolation and sealing and wiring. The upper end of the inner side of the upper shell 12 is integrated with a control circuit module 2, including a telemetry communication circuit, an electric motor drive circuit and a voltage protection circuit, and the lower end of the inner side is fixed with an electric motor 3 and a reducer 4, and the outer side is protected by a shock absorbing block 11 and a shock absorbing assembly 13.

[0017] The intermediate joint 5 connects the upper shell 12 and the lower shell 15 , the striker 14 is arranged in the intermediate joint 5 , and the inner side of the lower end of the intermediate joint 5 is connected to the release claw 6 .

[0018] The striker 14 has a female thread on the inner side of the upper end and a pin key on the outer side. It is arranged in the channel A and does not rotate. The lower end is in the lower shell 15, and a sealing ring is arranged in the middle.

[0019] The reducer 4 is a finished product on the market, with transmission rods arranged at the upper and lower ends, the upper end of which is connected to the electric motor; the outer side of the rotating rod at the lower end is a male thread, which is connected to the female thread on the inner side of the upper end of the striker.

[0020] The release claws 6 are arranged as four independent claws around a circle.

[0021] The inner side of the lower shell 15 is provided with a thimble 7 , a locking ring 8 , a salvage cap assembly 16 , and a locking ring fixing pin 17 .

[0022] The lower end of the salvage cap assembly 16 is provided with an external thread connected to a lower connector 19, the upper end is provided with a salvage cap, the inner side of the lower end is provided with a lower single core plug 9, and the outer side of the lower end is provided with an anti-rotation top screw 18.

[0023] The salvage cap assembly is a T-shaped structure, made of a high-strength alloy material, and has a channel B arranged inside.

[0024] The salvage cap assembly 16 is reliably connected to the intermediate joint 5 via the release claw 6 , the locking ring 8 , and the locking ring fixing pin 17 , and the locking ring 8 and the locking ring fixing pin 17 are connected together.

[0025] The inner side of the upper end of the lower connector 19 is provided with an internal thread, which is connected to the salvage cap assembly 16, and the outer side of the lower end is provided with an external thread, which is directly connected to the instrument string below.

[0026] The ejector assembly 7 is provided with an inner needle and an outer sleeve which are connected together, and the outer sleeve is T-shaped.

[0027] The working principle of the present invention is as follows: when release is required, the control circuit module 2 is started through the ground control instrument to drive the electric motor 3 to work, the striker 14 is pushed downward through the reducer 4, the impact ejector 7 moves downward, and hits the locking ring fixing pin 17, driving the locking ring 8 to move downward, the release claw 6 eliminates the restraint, and at the same time the inner needle of the ejector moves downward, also driving the outer sleeve to move downward, so that the release claw 6 begins to open outward, the salvage cap on the salvage cap assembly 16 is released, the cable is pulled up to make the device stressed, the lower shell 15 is disengaged from the salvage cap assembly 16, the salvage cap assembly 16 is exposed, and the lower connector 19 and the instrument string below are left in the well, which is convenient for subsequent continuous tubing salvage operations.

Claims

1. A cable controlled safety release device for oil and gas wells, comprising an upper joint, a salvage cap, and a lower joint, wherein the salvage cap is threadedly connected to the lower joint, and characterized in that: It also includes an upper shell, an intermediate joint, a lower shell, an electric motor, a striker, an ejector, a release claw, a locking ring, and a locking ring fixing pin; the upper shell is sleeved with the intermediate joint, and the intermediate joint is slidably sleeved with the lower shell; the intermediate joint is provided with a channel A connecting the upper and lower shells; the electric motor is arranged in the upper shell, and is connected to the striker through a reducer drive; the striker is slidably inserted in the channel A and linked with the ejector; the root of the release claw is fixedly arranged on the intermediate joint, and the claw is clamped on the lower joint; the locking ring is slidably sleeved on the claw and locked with the claw; the The locking ring fixing pin is fixedly connected to the locking ring; the ejector is linked to the locking ring fixing pin, and the ejector includes an inner pin and an outer sleeve; a hole B is arranged inside the salvage cap, and the ejector is located in the hole B. The electric motor pushes the striker downward through the reducer, hits the ejector to move downward, and hits the locking ring fixing pin, driving the locking ring to move downward, and the release claw eliminates the restraint. At the same time, the inner pin of the ejector moves downward, and the outer sleeve of the ejector also moves downward, so that the release claw begins to open outward to release the salvage cap.

2. The oil and gas well cable controlled safety release device according to claim 1, characterized in that: A control circuit module is also provided in the upper shell, and the electric motor is connected to the upper single core plug through the control circuit module. The control circuit module includes a telemetry communication circuit, an electric motor drive circuit and a voltage protection circuit.

3. The oil and gas well cable controlled safety release device according to claim 2, characterized in that: It also includes a salvage cap, the release claw is clamped on the salvage cap, and the salvage cap is threadedly connected to the lower joint.

4. The oil and gas well cable controlled safety release device according to claim 2, characterized in that: It also includes a shock absorbing block, which is arranged between the control circuit module and the inner wall of the upper shell.

5. An oil and gas well cable controlled safety release device according to any one of claims 1 to 4, characterized in that: The utility model also comprises a shock absorbing body, wherein the shock absorbing body is wrapped around the electric motor.

6. An oil and gas well cable controlled safety release device according to any one of claims 1 to 4, characterized in that: A sealing ring is arranged between the upper shell and the middle joint.

7. An oil and gas well cable controlled safety release device according to any one of claims 1 to 4, characterized in that: One end of the lower joint is provided with an internal thread, one end of the salvage cap is provided with an external thread, and the salvage cap and the lower joint are threadedly connected.

8. An oil and gas well cable controlled safety release device according to any one of claims 1 to 4, characterized in that: A channel B is provided in the salvage cap, and at least two axial through grooves are axially provided at the lower end of the salvage cap; the locking ring fixing pin passes through the axial barrel groove, and both ends are fixedly connected to the locking ring; the ejector pin is slidably inserted into the channel B, and the lower end is placed on the locking fixing pin.

9. An oil and gas well cable controlled safety release device according to any one of claims 1 to 4, characterized in that: The release claws are provided with a plurality of claws in pairs.

10. The oil and gas well cable controlled safety release device according to claim 9, characterized in that: There are four claws.

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