Automatic balance pressure relief control system and method for operation under pressure

Abstract

The invention belongs to the technical field of petroleum automatic under-pressure workover devices, and discloses an under-pressure operation automatic balance pressure relief control system and method.A wellhead pressure detection device is installed on a wellhead blowout preventer set or a wellhead four-way joint, and a pipe hoop detection device is installed on the upper portion of a wellhead and the lower portion of a lower working blowout preventer; the lower working blowout preventer is installed on the lower portion of the four-way short section, one end of the four-way short section is connected with the balance valve, the other end of the four-way short section is connected with the pressure relief valve, the other end of the four-way short section is connected with the balance pressure detection device, the upper working blowout preventer is installed on the upper portion of the four-way short section, and the balance gate valve and the pressure relief gate valve are switch valves. Opening and closing of a balance valve and a pressure release valve are automatically achieved, opening and closing of a flashboard blowout preventer are controlled at the same time, a pipe column and a pipe hoop are completed, and high-pressure well repairing under pressure is achieved. According to the method, the balanced pressure relief operation can be automatically completed according to the pipe hoop position information, the automatic reverse coupling operation of the pipe column pipe hoop in the high-pressure state is completed, the labor intensity of workers is relieved, and the safety risk of construction operation is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of oil automation pressure - maintained workover devices, and relates to a pressure - maintained operation automatic balance pressure - relief control system and method. Background Art

[0002] During the oil and gas workover operation, due to the high bottom - hole pressure, in the workover process, in order to prevent the uncontrolled spraying of liquid or gas in the casing, a working blowout preventer is generally used for sealing during the pipe string tripping. The working blowout preventer is divided into a ram blowout preventer and an annular blowout preventer. Generally, when the wellhead pressure is lower than 6 MPa, an annular blowout preventer is used, and the pipe coupling can directly pass through the annular blowout preventer forcefully without causing liquid or gas leakage. Once the wellhead pressure is higher than 10 MPa, using only the annular blowout preventer cannot ensure the operation safety, and it is necessary to cooperate with the ram blowout preventer for tripping operations. Due to the structural characteristics of the ram blowout preventer, the pipe coupling cannot directly pass through forcefully, so it is necessary to perform the operation of connecting the coupling in reverse through two ram blowout preventers. When the ram blowout preventer is in the closed state, it seals the casing. When the well pressure is high, the ram blowout preventer has the function of assisting in sealing by well pressure. If the ram blowout preventer is forced to open, it will cause damage to the sealing body and lead to safety accidents. Therefore, during the operation of connecting the coupling in reverse, it is necessary to balance the wellhead pressure and the pressure in the upper space of the ram blowout preventer, and then open the ram blowout preventer after balancing.

[0003] The traditional operation method is to manually operate the hydraulic handle to open the wellhead balance valve and pressure - relief valve. The operator needs to judge based on experience whether the balance is achieved or the pressure - relief is complete, and strictly follow the logical action sequence to ensure the smooth progress of the construction. At the same time, due to the different lengths of the pipe strings, for the pipe string lifted out of the wellhead, the position of the pipe coupling cannot be accurately judged, and it can only be judged that the coupling arrives based on the load change after the pipe coupling contacts the ram. Once careless, it is very easy to have workover accidents. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a pressure - maintained operation automatic balance pressure - relief control method, which is an automatic balance pressure - relief control method based on an automated pressure - maintained workover device. This method is used for high - pressure pressure - maintained automated workover operations, and can automatically complete the balance pressure - relief operation of connecting the coupling in reverse according to the pipe coupling detection signal, reducing the labor intensity of workers and reducing the safety risks of construction operations. In the current field of pressure - maintained operation automation, this technical method is the first of its kind.

[0005] The above object of the present invention is achieved by the following technical solutions:

[0006] The present invention provides a pressure - maintained operation automatic balance pressure - relief control method, which is applied to automated pressure - maintained workover operations. This method is based on an automated pressure - maintained operation device.

[0007] A pressure - operated automatic balanced pressure - relief control system, including a wellhead pressure detection device, a pipe coupling detection device, a lower working blowout preventer, a four - way nipple, a balance gate valve, a pressure - relief gate valve, a balance pressure detection device, an upper working blowout preventer, and a control system, etc.

[0008] The wellhead pressure detection device is installed on the wellhead blowout preventer group or the wellhead four - way, and can monitor the change of the wellhead casing pressure in real time.

[0009] The pipe coupling detection device is installed above the wellhead and below the lower working blowout preventer, and can detect whether the pipe coupling passes in real time. When the pipe coupling passes, it sends a pipe - coupling - arrived signal to the control system.

[0010] The lower working blowout preventer is installed above the pipe coupling detection device and below the four - way nipple, and is a gate - type working blowout preventer. Position detectors for opening and closing in place are arranged on both sides of the blowout preventer, and can feedback the position state of the working blowout preventer in real time.

[0011] The four - way nipple is a rigid four - way connector, with one end connected to the balance valve, one end connected to the pressure - relief valve, and one end connected to the balance pressure detection device.

[0012] The upper working blowout preventer is installed above the four - way nipple, and is a gate - type working blowout preventer. Position detectors for opening and closing in place are arranged on both sides of the blowout preventer, and can feedback the position state of the working blowout preventer in real time.

[0013] Both the balance gate valve and the pressure - relief gate valve are on - off valves, and are equipped with sensors for detecting the opening and closing of the gate valve, which can feedback the working state of the gate valve in real time.

[0014] The balance pressure detection device is installed on an interface of the four - way nipple, and is used to monitor the pressure between the upper and lower working blowout preventers.

[0015] The control system is a PLC programmable control system, which can collect the wellhead pressure and pipe - coupling signals, automatically realize the opening and closing of the balance valve and the pressure - relief valve, and at the same time control the opening and closing of the gate - type blowout preventer, complete the passing of the pipe string pipe coupling through the wellhead blowout preventer group, and realize high - pressure pressure - operated well repair.

[0016] A pressure - operated automatic balanced pressure - relief control system and method, and this method is applied to automatic pressure - operated balanced pressure - relief: Detect the position information of the pipe string pipe coupling through the pipe coupling detection device, and automatically perform the logic actions of balanced pressure - relief through the coupling position information, various position sensors, and pressure sensors, so as to realize the safe passing of the pipe string through the working blowout preventer group.

[0017] The pressure - operated operation of the pipe string is divided into pipe - pulling and pipe - lowering operations.

[0018] The control method during the pipe pulling operation is as follows: Before the operation, first measure the well pressure data using the wellhead pressure detection device and select the high-pressure or low-pressure mode. The low-pressure mode is not within the scope of this discussion, and only high-pressure operations are involved. First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief ram valve is in the closed state, the balance ram valve is in the open state, the upper working half-closed is in the closed state, and the lower working half-closed is in the open state. During the process of pulling the pipe string out of the wellhead, after the pipe coupling detection device detects the signal of the pipe coupling passing through, it transmits the pipe coupling signal to the control system through the CAN bus. The control system automatically calculates based on the current lifting position, stops when the pipe coupling is lifted to the position of the four-way nipple, that is, after passing over the lower blowout preventer. The control system issues an automatic pressure relief instruction: First, close the lower blowout preventer. After it is closed in place, open the pressure relief ram valve. At the same time, after the balance pressure detection device detects that the pressure between the upper and lower half-closed is reduced to 0, open the upper working blowout preventer, close the pressure relief ram valve, and the automatic pressure relief is completed. After these two actions are completed, automatically lift the pipe string to the calculated height position again, that is, stop after passing over the upper working blowout preventer. The control system issues an automatic balance instruction: First, close the upper working blowout preventer. After it is closed in place, open the balance ram valve to connect the wellhead pressure through the pipeline with the upper and lower working blowout preventers for pressure balance. When the value of the balance pressure detection device is equal to the value of the wellhead pressure detection device, the pressure balance is achieved. At this time, open the lower working blowout preventer, and the automatic balance is completed. At this time, the pipe coupling has safely passed through the upper working blowout preventer and the lower working blowout preventer.

[0019] The control method during the lower pipe operation is as follows: Before the operation, first measure the well pressure data using the wellhead pressure detection device, and select the high-pressure or low-pressure mode. The low-pressure mode is not within the scope of this discussion, only high-pressure operations are involved. First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief gate valve 8 is in the closed state, the balance gate valve is in the closed state, the upper working half-closed is in the open state, and the lower working half-closed is in the closed state. During the process of lowering the pipe string from the platform into the well, according to the program algorithm, automatically control the pipe string collar to be lowered to the position of the four-way nipple, that is, stop after passing over the upper working blowout preventer. The control system issues an automatic balance command: First, close the upper working blowout preventer. After closing in place, open the balance gate valve to connect the wellhead pressure through the pipeline between the upper working blowout preventer and the lower working blowout preventer for pressure balance. When the value of the balance pressure detection device is equal to the value of the wellhead pressure detection device, the pressure balance is achieved. At this time, open the lower working blowout preventer, and the automatic balance is completed. After the lower working blowout preventer is opened in place, the system automatically lowers the pipe string again. After the collar detection device detects the collar signal, the control system issues an automatic pressure relief command: First, close the lower working blowout preventer. After closing in place, open the pressure relief gate valve. At the same time, after the balance pressure detection device detects that the pressure between the upper working blowout preventer and the lower working blowout preventer has dropped to 0, open the upper working blowout preventer and close the pressure relief gate valve, and the automatic pressure relief is completed. At this time, the pipe string collar has safely passed through the upper working blowout preventer and the lower working blowout preventer.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] This method can automatically complete the balance and pressure relief operations according to the collar position information, complete the automatic reverse coupling operation of the pipe string collar under high-pressure conditions, reduce the manual labor intensity, and reduce the safety risks of construction operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, the following further detailed description of the present invention will be given in combination with the drawings and specific embodiments.

[0023] Figure 1 It is a schematic diagram of the equipment composition of the present invention.

[0024] Among them, 1. Collar detection device, 2. Lower working blowout preventer, 3. Four-way nipple, 4. Balance gate valve, 5. Wellhead pressure detection device, 6. Upper working blowout preventer, 7. Balance pressure detection device, 8. Pressure relief gate valve, 9. Control system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Refer to the attached Figure 1As shown in the figure, the present invention provides a method for automatically balancing and relieving pressure during pressure-bearing operations. This method is based on an automated pressure-bearing operation device. The automated pressure-bearing operation device includes a pipe coupling detection device 1, a lower working blowout preventer 2, a four-way short joint 3, a balance gate valve 4, a wellhead pressure detection device 5, an upper working blowout preventer 6, a balance pressure detection device 7, a pressure relief gate valve 8, and a control system 9.

[0026] This method is applied to the balance and pressure relief of automated pressure-bearing operations: through the pipe coupling detection device 1, the position information of the pipe string couplings is detected, and through the coupling position information, various position sensors, and pressure sensors, the balance and pressure relief logic actions are automatically executed, thereby enabling the pipe string to safely pass through the blowout preventer group.

[0027] The wellhead pressure detection device 5 is installed on the wellhead blowout preventer group or the wellhead four-way joint, and can monitor the change of the wellhead casing pressure in real time.

[0028] The pipe coupling detection device 1 is installed above the wellhead and below the lower working blowout preventer 2, and can detect in real time whether the pipe coupling passes through. When the pipe coupling passes through, a pipe coupling arrival signal is sent to the control system.

[0029] The lower working blowout preventer 2 is installed above the pipe coupling detection device and below the four-way short joint 3, and is a gate-type working blowout preventer. Open and closed in-place position detectors are provided on both sides of the blowout preventer, and can feedback the position state of the working blowout preventer in real time.

[0030] The four-way short joint 3 is a rigid four-way connector. Among them, one end is connected to the balance valve, one end is connected to the pressure relief valve, and one end is connected to the balance pressure detection device 7.

[0031] The upper working blowout preventer 6 is installed above the four-way short joint 3, and is a gate-type working blowout preventer. Open and closed in-place position detectors are provided on both sides of the blowout preventer, and can feedback the position state of the working blowout preventer in real time

[0032] Both the balance gate valve 4 and the pressure relief gate valve 8 are on-off valves 3, and sensors for detecting the opening and closing of the gate valves are provided, and can feedback the working state of the gate valves in real time.

[0033] The balance pressure detection device 7 is installed on an interface of the four-way short joint 3, and is used to monitor the pressure between the upper and lower working blowout preventers.

[0034] The control system 9 is a PLC programmable control system, which can collect the wellhead pressure and pipe coupling signals, automatically realize the opening and closing of the balance valve and the pressure relief valve, and at the same time control the opening and closing of the gate-type blowout preventer, complete the passing of the pipe string coupling through the wellhead blowout preventer group, and realize high-pressure pressure-bearing well repair.

[0035] The pressure-bearing operation of the pipe string is divided into pipe pulling and pipe running operations.

[0036] The control method during the pipe pulling operation is as follows: Before the operation, first measure the well pressure data according to the wellhead pressure detection device 5, and select the high-pressure or low-pressure mode. The low-pressure mode is not within the scope of this discussion, and only high-pressure operations are involved. First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief gate valve 8 is in the closed state, the balance gate valve 4 is in the open state, the upper working half-closed preventer 6 is in the closed state, and the lower working half-closed preventer 2 is in the open state. During the process of pulling the pipe string out of the wellhead, after the pipe coupling detection device 1 detects the signal of the pipe coupling passing through, it transmits the pipe coupling signal to the control system 9 through the CAN bus. The control system 9 automatically calculates according to the current lifting position, and stops after lifting the pipe coupling to the position of the four-way nipple 3, that is, after passing over the lower working blowout preventer 2. The control system 9 issues an automatic pressure relief instruction: First, the lower working blowout preventer 2 is closed. After it is closed in place, the pressure relief gate valve 8 is opened. At the same time, after the balance pressure detection device detects that the pressure between the upper and lower half-closed preventers has dropped to 0, the upper working blowout preventer 6 is opened, and the pressure relief gate valve 8 is closed, and the automatic pressure relief is completed. After both of these actions are completed, the pipe string is automatically lifted again to the calculated height position, that is, after passing over the upper working blowout preventer 6 and then stopped. The control system 9 issues an automatic balance instruction: First, the upper working blowout preventer 6 is closed. After it is closed in place, the balance gate valve 4 is opened to connect the wellhead pressure through the pipeline with the upper and lower working blowout preventers for pressure balance. When the value of the balance pressure detection device 7 is equal to the value of the wellhead pressure detection device 5, the pressure balance is achieved. At this time, the lower working blowout preventer 2 is opened, and the automatic balance is completed. At this time, the pipe coupling has safely passed through the upper working blowout preventer 6 and the lower working blowout preventer 2.

[0037] The control method during the operation of the lower pipe is specifically as follows: Before the operation, first, according to the well pressure data measured by the wellhead pressure detection device 5, select the high-pressure or low-pressure mode. The low-pressure mode is not within the scope of this discussion, and only high-pressure operations are involved. First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief ram valve 8 is in the closed state, the balance ram valve 4 is in the closed state, the upper working half-closed preventer 6 is in the open state, and the lower working half-closed preventer 2 is in the closed state. During the process of lowering the pipe string from the platform into the well, according to the program algorithm, the pipe string collar is automatically controlled to be lowered to the position of the four-way nipple 3, that is, after passing over the upper working blowout preventer 6, it stops. The control system 9 issues an automatic balance instruction: First, close the upper working blowout preventer 6. After closing in place, open the balance ram valve 4 to connect the wellhead pressure through the pipeline between the upper working blowout preventer 6 and the lower working blowout preventer 2 for pressure balance. When the value of the balance pressure detection device 7 is equal to the value of the wellhead pressure detection device 5, the pressure balance is achieved. At this time, open the lower working blowout preventer 2, and the automatic balance is completed. After the lower working blowout preventer 2 is opened in place, the system automatically lowers the pipe string again. After the collar detection device 1 detects the collar signal, the control system 9 issues an automatic pressure relief instruction: First, close the lower working blowout preventer 2. After closing in place, open the pressure relief ram valve 8. At the same time, after the balance pressure detection device 7 detects that the pressure between the upper working blowout preventer 6 and the lower working blowout preventer 2 has dropped to 0, open the upper working blowout preventer 6 and close the pressure relief ram valve 8, and the automatic pressure relief is completed. At this time, the pipe string collar has safely passed through the upper working blowout preventer 6 and the lower working blowout preventer 2.

[0038] As described above, it is only a preferred embodiment of the present invention, and there is no limitation in any form to the present invention. Any simple modifications, equivalent changes or decorations made by those skilled in the art using the disclosed technical content all fall within the protection scope of the present invention.

Claims

1. A pressure - operated automatic balance pressure - relief control system, Characterized in that, It includes a wellhead pressure detection device (5), a pipe coupling detection device (1), a lower working blowout preventer (2), a four - way nipple (3), a balance gate valve (4), a pressure - relief gate valve (8), a balance pressure detection device (7), an upper working blowout preventer (6) and a control system (9). The wellhead pressure detection (5) device is installed on the wellhead blowout preventer group or the wellhead four - way. The pipe coupling detection device (1) is installed above the wellhead and below the lower working blowout preventer (2). The lower working blowout preventer (2) is installed below the four - way nipple (3). One end of the four - way nipple (3) is connected to the balance valve, one end is connected to the pressure - relief valve, and one end is connected to the balance pressure detection device (7). The upper working blowout preventer (6) is installed above the four - way nipple (3). The balance gate valve (4) and the pressure - relief gate valve (8) are both on - off valves. The control system (9) is a PLC programmable control system, which collects the wellhead pressure and pipe coupling signals, automatically realizes the opening and closing of the balance valve and the pressure - relief valve, and at the same time controls the opening and closing of the ram blowout preventer to complete the pipe string coupling.

2. The pressure - operated automatic balance pressure - relief control system according to claim 1, Characterized in that, The lower working blowout preventer (2) is a ram - type working blowout preventer.

3. The pressure - operated automatic balance pressure - relief control system according to claim 1, Characterized in that, The upper working blowout preventer (6) is a ram - type working blowout preventer.

4. The pressure - operated automatic balance pressure - relief control system according to claim 1, Characterized in that, The four - way nipple (3) is a rigid four - way connector.

5. The pressure - operated automatic balance pressure - relief control system according to claim 1, Characterized in that, Both the balance gate valve (4) and the pressure - relief gate valve (8) are provided with sensors for detecting the opening and closing of the gate valve.

6. A pressure - operated automatic balance pressure - relief control method, Characterized in that, The position information of the pipe string coupling is detected by the pipe coupling detection device (1), and through the coupling position information, various position sensors and pressure sensors, the balance pressure - relief logic action is automatically executed, so as to realize the safe passage of the pipe string through the working blowout preventer group, which is divided into pipe pulling operation and pipe running operation.

7. The automatic balanced pressure relief control method for pressure-bearing operations according to claim 6, characterized in that the control method during pipe lifting operations is specifically as follows: Before the operation, first measure the well pressure data according to the wellhead pressure detection device (5). First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief gate valve (8) is in the closed state, the balance gate valve (4) is in the open state, the upper working half-closed (6) is in the closed state, and the lower working half-closed (2) is in the open state. During the process of lifting the pipe string from the wellhead, after the pipe coupling detection device (1) detects the signal of the pipe coupling passing through, it transmits the pipe coupling signal to the control system (9) through the CAN bus. The control system (9) automatically calculates according to the current lifting position and stops when the pipe coupling is lifted to the position of the four-way short joint (3), that is, after passing over the lower working blowout preventer (2). The control system (9) issues an automatic pressure relief instruction: First, close the lower working blowout preventer (2). After closing in place, open the pressure relief gate valve (8). At the same time, after the balance pressure detection device detects that the pressure between the upper and lower half-closed is reduced to 0, open the upper working blowout preventer (6), close the pressure relief gate valve (8), and the automatic pressure relief is completed. After both of these actions are completed, automatically lift the pipe string to the calculated height position again, that is, stop after passing over the upper working blowout preventer (6). The control system (9) issues an automatic balance instruction: First, close the upper working blowout preventer (6). After closing in place, open the balance gate valve (4) to connect the wellhead pressure through the pipeline with the upper and lower working blowout preventers for pressure balance. When the value of the balance pressure detection device (7) is equal to the value of the wellhead pressure detection device (5), the pressure balance is achieved. At this time, open the lower working blowout preventer (2), and the automatic balance is completed. At this time, the pipe coupling has safely passed through the upper working blowout preventer (6) and the lower working blowout preventer (2).

8. The automatic balanced pressure relief control method for pressure-bearing operations according to claim 6, characterized in that, The control method during the operation of the lower pipe is specifically as follows: Before the operation, first measure the well pressure data according to the wellhead pressure detection device (5). First, perform the initialization operation of the equipment. After the initialization operation, the pressure relief gate valve (8) is in the closed state, the balance gate valve (4) is in the closed state, the upper working half seal (6) is in the open state, and the lower working half seal (2) is in the closed state. During the process of lowering the pipe string from the platform into the well, according to the program algorithm, automatically control the pipe string collar to be lowered to the position of the four-way nipple (3), that is, stop after passing over the upper blowout preventer (6). The control system (9) issues an automatic balance command: First, close the upper blowout preventer (6). After closing in place, open the balance gate valve (4) to connect the wellhead pressure through the pipeline between the upper blowout preventer (6) and the lower blowout preventer (2) for pressure balance. When the value of the balance pressure detection device (7) is equal to the value of the wellhead pressure detection device (5), the pressure balance is achieved. At this time, open the lower blowout preventer (2) to complete the automatic balance; after the lower blowout preventer (2) is opened in place, the system automatically lowers the pipe string again. After the pipe collar detection device (1) detects the pipe collar signal, the control system (9) issues an automatic pressure relief command: First, close the lower blowout preventer (2). After closing in place, open the pressure relief gate valve (8). At the same time, after the balance pressure detection device (7) detects that the pressure between the upper blowout preventer (6) and the lower blowout preventer (2) has dropped to 0, open the upper blowout preventer (6) and close the pressure relief gate valve (8) to complete the automatic pressure relief; at this time, the pipe string collar has safely passed through the upper blowout preventer (6) and the lower blowout preventer (2).

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