CN102409994A - Ram blowout preventer based on linear motor - Google Patents

Abstract

The invention belongs to the technical field of petroleum drilling equipment, and relates to a ram blowout preventer based on a linear motor. It includes a housing (1), a gate (2), a side door (3), an end cover (4), a gate shaft (5) and a drive part of the gate shaft (6). The gate shaft driving part (6) consists of a coupling (7), a piston rod (8), a large hydraulic cylinder (9), a two-position four-way solenoid valve (10), an oil tank (11), and a cylindrical linear motor ( 12), small hydraulic cylinder (15) and one-way valve (16) form. The linear motor (12) drives the piston rod of the small hydraulic cylinder (15) to perform reciprocating motion. According to Pascal's principle, a relatively small pressure is applied on the small piston, and the movement of the gate (2) can be obtained on the large piston. The required large thrust, the large thrust drives the gate shaft to move, and the switch function of the blowout preventer can be completed. The invention has the advantages of fast control response speed and remote control; no complicated hydraulic drive system and simple structure.

Description

A ram blowout preventer based on linear motor

technical field

The invention belongs to the technical field of petroleum drilling equipment, and relates to a ram blowout preventer based on a linear motor.

Background technique

The blowout preventer is a safety sealing wellhead device used to close the wellhead during oil testing, well workover, well completion and other operations to prevent blowout accidents. Ram blowout preventer is an important part of well control equipment, and it is the earliest blowout preventer used in oil drilling production.

The early ram blowout preventers were all manually controlled switches. This method is laborious, takes a long time to shut in the well, and the withstand voltage is relatively low, and there are many faults. It is easy to fail to seal the well during emergency shut-in, resulting in out-of-control blowout.

Modern oil drilling uses hydraulic ram blowout preventers, which can be switched quickly by hydraulic control, and the well can be shut down within 3-8 seconds; it is easy to operate; hydraulic ram blowout prevention can be realized through the reversing valve The switching action of the device; safe and reliable; convenient on-site maintenance; the sealing element of the hydraulic ram BOP can be replaced even if it is worn out during use. The working principle of the hydraulically driven ram BOP is that when a blowout or well kick occurs, the high-pressure power fluid enters the left and right liquid cylinders to close the cavity, and the piston is pushed to drive the ram shaft and the ram assembly along the guide ribs in the ram chamber to limit The orbits move to the center of the wellhead respectively to realize well closure. Similarly, to realize the opening of the blowout preventer, it is necessary to introduce high-pressure power fluid into the opening chambers of the left and right hydraulic cylinders. The ram blowout preventer has reliable sealing, high pressure resistance, and can close the wellhead for a long time; it can be equipped with various rams, such as full-sealing rams, half-sealing rams, shear rams and variable-diameter rams. Because the ram BOP can be equipped with rams with various functions, it can realize many functions.

However, the hydraulic ram BOP requires a complex hydraulic control system to drive, and the fluid signal has the disadvantages of short transmission distance, slow response speed, and easy damage to the hydraulic tube bundle. Ram blowout preventers based on linear motors have not been reported at home and abroad.

Contents of the invention

The object of the present invention is to provide a ram blowout preventer based on a linear motor, which uses the linear motor to drive the ram shaft to realize all-electric control of the blowout preventer system.

Principle of the present invention: a ram blowout preventer based on a linear motor, which consists of a housing 1, a ram 2, a side door 3, an end cover 4, a ram shaft 5 and a ram shaft driving part 6. The gate shaft driving part 6 is composed of a coupling 7, a piston rod 8, a large hydraulic cylinder 9, a two-position four-way solenoid valve 10, an oil tank 11, a cylindrical linear motor 12, a small hydraulic cylinder 15 and a one-way valve 16. The gate shaft 5 is connected with a large hydraulic cylinder 9, which is connected with a small hydraulic cylinder 15 through a two-position four-way solenoid valve 10, and the small hydraulic cylinder is connected with the secondary 14 of the linear motor, and the linear motor drives The piston rod of the small hydraulic cylinder 15 reciprocates, and the small hydraulic cylinder continuously pushes the hydraulic oil into the cavity of the large hydraulic cylinder 9. According to Pascal’s principle, a relatively large thrust can be obtained at the piston rod of the large hydraulic cylinder, and the piston rod drives The ram shaft moves to realize the function of the blowout preventer switch. In addition, due to the function of the one-way valve, the device also has a self-locking function.

The present invention has the following advantages:

1. Using electrical signals to control the blowout preventer, the response speed is fast, and long-distance control can be realized.

2. Compared with the hydraulic control ram BOP, the complex hydraulic system for externally driving the BOP is omitted, such as hydraulic components such as accumulators, pumps and solenoid valves.

3. There is no oil circuit inside the ram blowout preventer, and the structure is simple.

4. There is no special manual or hydraulic locking device, and self-locking is performed through hydraulic cylinders and check valves, which simplifies the structure of the blowout preventer.

5. Utilizing the principle of a small cylinder pushing a large cylinder, the work is stable and the thrust of the driving gate is increased.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a linear motor ram preventer.

FIG. 2 is a schematic diagram of the principle of the gate shaft driving part 6 in FIG. 1 .

Detailed ways

See Figure 1. The main structure of the linear motor-based ram blowout preventer of the present invention includes a housing 1 , a ram 2 , a side door 3 , an end cover 4 , a ram shaft 5 and a ram shaft driving part 6 .

See Figure 2. The gate shaft driving part 6 mainly includes a shaft coupling 7, a piston rod 8, a large hydraulic cylinder 9, a two-position four-way solenoid valve 10, an oil tank 11, a cylindrical linear motor 12, a small hydraulic cylinder 15 and a one-way valve 16. The cylindrical linear motor 12 is composed of a primary 13 of the linear motor and a secondary 14 of the linear motor, and the primary 13 of the linear motor is fixed on the inner wall of the end cover 4 .

When the solenoid valve 10 is in the position shown in Figure 2, the small hydraulic cylinder 15 is connected to the closing cavity of the large hydraulic cylinder 9, and the linear motor 12 can push the gate to complete the closing action. After the control center issued the order to close the ram BOP, the linear motor 12 started to run, and the motor secondary 14 began to reciprocate, pushing the piston rod of the small hydraulic cylinder 15 to reciprocate. Due to the effect of the one-way valve 16, the hydraulic oil can only enter the large hydraulic cylinder 9 from the small hydraulic cylinder 15, so the hydraulic oil in the oil tank 11 is continuously pushed into the right chamber of the large hydraulic cylinder 9, and the hydraulic oil in the left chamber of the large hydraulic cylinder 9 The hydraulic oil then flows into the oil tank, and the hydraulic pressure of the hydraulic cylinder in the right cavity of the hydraulic cylinder 9 is continuously raised, pushing the piston rod 8 to move to the left, thereby completing the closing action of the blowout preventer. Afterwards, the linear motor 12 is powered off, and simultaneously, due to the effect of the one-way valve, the ram blowout preventer also has the effect of hydraulic self-locking. When the blowout preventer needs to be opened, the electromagnetic valve 10 is first controlled to change direction, so that the oil supply circuit of the small hydraulic cylinder 15 is connected with the left chamber of the large hydraulic cylinder 9, and the right chamber of the large hydraulic cylinder 9 is connected with the circuit flowing into the oil tank , and then send an open command to start the linear motor 12, the small hydraulic cylinder 15 starts to pump liquid, the high-pressure liquid pumped by the small hydraulic cylinder 15 opens the check valve 16 and enters the left chamber of the large hydraulic cylinder 9 through the oil supply circuit, and the left chamber of the large hydraulic cylinder 9 The hydraulic pressure in the cavity increases continuously with the entry of hydraulic oil, thereby pushing the ram shaft 5 to move to the right, and the blowout preventer completes the opening action. The linear motor 12 drives the piston rod of the small hydraulic cylinder 15 to perform reciprocating motion. According to Pascal's principle, a relatively small pressure is applied on the small piston, and the large thrust required to push the gate 2 to move can be obtained on the large piston. The large thrust drives the ram shaft to move, and the switch function of the blowout preventer can be completed.

Claims (2)

1. A ram blowout preventer based on a linear motor, which includes a housing (1), a ram (2), a side door (3), an end cover (4), a ram shaft (5) and a ram shaft drive The part (6) is characterized in that the gate shaft driving part (6) is located in the mold cavity formed by the end cover (4) and the side door (3). 2. The ram blowout preventer based on linear motor according to claim 1, characterized in that: the ram shaft driving part (6) is composed of a coupling (7), a piston rod (8), a large hydraulic cylinder (9 ), a two-position four-way solenoid valve (10), a fuel tank (11), a cylindrical linear motor (12), a small hydraulic cylinder (15) and a check valve (16), the gate shaft (5) and the large hydraulic pressure The piston rod (8) of the cylinder (9) is connected, the large hydraulic cylinder (9) is connected with the small hydraulic cylinder (15) through a two-position four-way solenoid valve (10), and the piston rod of the small hydraulic cylinder (15) is connected to the cylinder The secondary (14) of the type linear motor is connected.

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