Efficient energy-saving hydraulic control safety valve executing mechanism and using method thereof

Abstract

The invention aims to provide an efficient energy-saving hydraulic control safety valve executing mechanism and a using method thereof, and belongs to the technical field of valve control, the efficient energy-saving hydraulic control safety valve executing mechanism comprises an oil tank, a high-low pressure valve set and a fusible plug, a first pipeline is arranged at one end of the bottom of the oil tank, and a manual pump, a one-way valve, a main oil source energy accumulator and a main oil source pressure gauge are sequentially arranged on the first pipeline; the high-low pressure valve set is connected with a field gas source, the fusible plug is connected with a pilot oil source energy accumulator and a first pilot pressure gauge through a second pipeline, the top end of the oil tank is connected with the first pipeline through a third pipeline, the third pipeline is provided with a second stop valve and a hydraulic control pilot valve, a fourth pipeline is arranged between the third pipeline and the first pipeline, and the fourth pipeline is provided with a first stop valve. The hydraulic control pilot valve is connected with the second pipeline through a fifth pipeline. The pressure maintaining time of the hydraulic control safety valve can be prolonged, and the pressurizing frequency of the manual pump is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of valve control, and in particular relates to a high-efficiency and energy-saving hydraulically controlled safety valve actuator and a use method thereof. Background Art

[0002] Conventional oil and gas fields, coalbed methane fields and tight sandstone gas fields are all characterized by remote exploration and development locations, inconvenient transportation, scattered gas wells, and a wide range of locations. Since the casing pressure of high-pressure gas wells is 15-30MPa, in order to save investment and ensure safe transportation, the operating pressure of the gathering and transportation pipeline is 0.6-4.0MPa, and the pressure difference at both ends is large. In order to ensure the safety of the wellhead pipelines and gathering and transportation pipelines of high-pressure gas wells and meet the needs of safe production of gas wells in gas fields, overpressure and underpressure protection hydraulically controlled safety valves are designed and installed at the wellhead position in the ground pumping and transportation process of gas wells with high wellhead pressure. This realizes the function of urgently cutting off the pipeline between a single well and the gathering and transportation station when a failure occurs in a certain link of the pumping and transportation process, greatly reducing the risk of secondary accidents caused by pipeline leakage, damage to gathering and transportation equipment, etc. The high and low pressure cut-off setting values ​​are adjustable, the high pressure adjustable range is 3.0-5.0Mpa, and the low pressure adjustable range is 0.6-1.5Mpa. Generally, the high pressure cut-off is set to 3.6Mpa and the low pressure cut-off is set to 0.8MPa. However, in actual use on site, it was found that the traditional hydraulically controlled safety valve was slow to increase pressure when using a manual pump, which was time-consuming and labor-intensive, and the pressure-maintaining time was short; the wiring method of the high and low pressure valve group was complicated, the control line and pipeline layout were cumbersome, and the inspection and maintenance costs were high. Summary of the invention

[0003] In view of the above problems, the present invention provides a high-efficiency and energy-saving hydraulically controlled safety valve actuator, which can effectively reduce the number of pressurization times of a manual pump, while significantly improving the pressure holding time and having extremely low operating and maintenance costs. After use, the pressure holding time of the hydraulically controlled safety valve is extended by 3-5 times, while the number of pressurization times of the manual pump of the hydraulically controlled safety valve is reduced by 52%-60%, providing a strong guarantee for the safe extraction and transmission of unconventional natural gas.

[0004] The present invention adopts the following technical solution: A high-efficiency and energy-saving hydraulically controlled safety valve actuator comprises an oil tank, a high- and low-pressure valve group and a fusible plug. A pipeline 1 is provided at one end of the bottom of the oil tank, and a manual pump, a one-way valve, a main oil source accumulator and a main oil source pressure gauge are provided on the pipeline 1 in sequence. The high- and low-pressure valve group is connected to an on-site gas source, and the fusible plug is connected to a pilot oil source accumulator and a pilot pressure gauge 1 through a pipeline 2. The top of the oil tank is connected to the pipeline 1 through a pipeline 3, and a stop valve 2 and a hydraulically controlled pilot valve are provided on the pipeline 3. A pipeline 4 is provided between the pipeline 3 and the pipeline 1, and a stop valve 1 is provided on the pipeline 4. The hydraulically controlled pilot valve is connected to the pipeline 2 through a pipeline 5.

[0005] Further, the high- and low-pressure valve group includes a high-pressure valve group and a low-pressure valve group, the high-pressure valve group is provided with H1 and L1 connection points, and an O1 sliding point is provided between the H1 and L1 connection points; the low-pressure valve group is provided with H2 and L2 connection points, and an O2 sliding point is provided between the H2 and L2 connection points, the O2 connection point is connected to the H1 connection point, the O1 connection point is connected to the fusible plug through pipeline nine, the L1 connection point is connected to pipeline three through pipeline six, the H2 connection point is connected to pipeline six, and pipeline nine is connected to pipeline two.

[0006] Furthermore, a stop valve three is provided between the pipeline five and the pipeline six.

[0007] Furthermore, a pipeline seven is provided between the pipeline one and the pipeline six, and a pilot oil source safety valve and a pressure reducing valve are provided on the pipeline seven. A pipeline eight is provided between the pilot oil source safety valve and the pressure reducing valve, and a pilot pressure gauge two is provided on the pipeline eight; wherein, the pipeline loop below the pressure reducing valve is a high-pressure control loop, and the pipeline loop above the pressure reducing valve is a low-pressure pilot control loop.

[0008] Furthermore, an air filter is provided at the top end of the oil tank, and an oil suction filter is provided at the bottom end.

[0009] Furthermore, the pipeline 1 is connected to a hydraulic actuator.

[0010] A method for using an efficient and energy-saving hydraulically controlled safety valve actuator comprises the following steps: S1. Before the hydraulically controlled safety valve works normally, a manual pump is used to pump the hydraulic oil in the oil tank through the one-way valve into the high-pressure control circuit and the low-pressure pilot control circuit. The high-pressure control circuit maintains the pressure in the circuit at 35Mpa through the main oil source accumulator; the high-pressure control circuit introduces the hydraulic oil into the low-pressure pilot control circuit through the pressure reducing valve. The pilot oil source accumulator of the low-pressure pilot control circuit maintains the pressure in the circuit at 5-20Mpa. A pilot oil source safety valve is installed in the low-pressure pilot circuit. When the manual pump increases the pressure, the pressure is too high, the pilot oil source safety valve in the low-pressure pilot control circuit opens, and the hydraulic oil flows back to the oil tank. At the same time, the oil pressure in the high-pressure control circuit drives the hydraulic actuator to compress the spring. The hydraulically controlled safety valve is in the open state under normal production conditions of the gas well. S2. When the on-site gas source pressure is lower than 0.8MPa, the low-pressure valve group in the low-pressure pilot control circuit works, H2 and O2 are connected, H1 and O1 are connected, the hydraulic oil flows back to the oil tank, the oil pressure in the high-pressure control circuit decreases, driving the hydraulic actuator to work, the spring expands, and the hydraulic control safety valve is closed; S3. When the on-site gas source pressure is higher than 3.6MPa, the high-pressure valve group in the low-pressure pilot control circuit works, L1 and O1 are connected, the hydraulic oil flows back to the oil tank, the oil pressure in the high-pressure control circuit decreases, driving the hydraulic actuator to work, the spring expands, and the hydraulic control safety valve is closed; S4. When the upstream and downstream gathering and transportation pipelines of the gas well need maintenance or pipeline reconstruction, open the stop valve 1 to relieve the pressure of the high and low pressure control circuits. The hydraulic oil flows back to the oil tank through the stop valve 1, driving the hydraulic actuator to work, the spring expands, and the hydraulic control safety valve is closed; S5. When a fire occurs at the gas well production site, the fusible plug melts, the pilot oil source leaks out, the hydraulic pilot valve opens, the hydraulic oil in the high-pressure control circuit flows into the oil tank, the control circuit is depressurized, the hydraulic actuator works, the spring expands, and the hydraulic safety valve is closed; S6. In case of emergency on site, stop valve 3 can be opened directly, the high and low pressure control circuits are depressurized, the hydraulic actuator works, the spring relaxes, and the hydraulically controlled safety valve is manually shut off in an emergency.

[0011] The beneficial effects of the present invention are as follows: 1. The present invention can prolong the pressure-maintaining time of the hydraulically controlled safety valve and reduce the number of pressurization times of the manual pump; 2. The high and low pressure valve group pipeline connection and wiring of the present invention are simple, which reduces the pressure leakage points in the actuator and greatly reduces the production and maintenance costs of the hydraulically controlled safety valve control actuator; 3. The present invention reduces the failure rate of the hydraulically controlled safety valve control actuator, greatly improves the safety performance, and provides a strong guarantee for the safe production of unconventional natural gas wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the hydraulically controlled safety valve actuator of the present invention; Figure 2 This is the state diagram of the hydraulically controlled safety valve actuator during the pressure-maintaining period of the hydraulic actuator after ventilation and pressure-pressurization; Figure 3 This is the state diagram of the hydraulically controlled safety valve actuator when the gas source pressure is too low; Figure 4 This is the state diagram of the hydraulically controlled safety valve actuator when the gas source pressure is too high; Among them: 1-air filter; 2-oil suction filter; 3-oil tank; 4-manual pump; 5-check valve; 6.1-stop valve one; 6.2-stop valve two; 7-hydraulic pilot valve; 8-pilot oil source safety valve; 9-stop valve three; 10-pressure reducing valve; 11.1-main oil source accumulator; 11.2-pilot oil source accumulator; 12.1-main oil source pressure gauge; 12.2-pilot pressure gauge one; 12.3-pilot pressure gauge two; 13-fusible plug; 14-high and low pressure valve group; 15-on-site gas source; 16-hydraulic actuator; 17-pipeline one; 18-pipeline two; 19-pipeline three; 20-pipeline four; 21-pipeline five; 22-pipeline six; 23-pipeline seven; 24-pipeline eight; 25-pipeline nine. DETAILED DESCRIPTION

[0013] The present invention will be further described with reference to the accompanying drawings.

[0014] like Figure 1 As shown, a high-efficiency and energy-saving hydraulically controlled safety valve actuator comprises an oil tank 3, a high- and low-pressure valve group 14 and a fusible plug 13. A pipeline 17 is provided at one end of the bottom of the oil tank 3. A manual pump 4, a one-way valve 5, a main oil source accumulator 11.1 and a main oil source pressure gauge 12.1 are provided on the pipeline 17 in sequence. The high- and low-pressure valve group 14 is connected to an on-site gas source 15. The fusible plug 13 is connected to a pilot oil source accumulator 11.2 and a pilot pressure gauge 12.2 through a pipeline 2 18. The top of the oil tank 3 is connected to the pipeline 1 17 through a pipeline 3 19. A stop valve 2 6.2 and a hydraulically controlled pilot valve 7 are provided on the pipeline 3 19. A pipeline 4 20 is provided between the pipeline 3 19 and the pipeline 1 17. A stop valve 6.1 is provided on the pipeline 4 20. The hydraulically controlled pilot valve 7 is connected to the pipeline 2 18 through a pipeline 5 21.

[0015] Furthermore, the high- and low-pressure valve group 14 includes a high-pressure valve group and a low-pressure valve group, the high-pressure valve group is provided with H1 and L1 connection points, and an O1 sliding point is provided between the H1 and L1 connection points; the low-pressure valve group is provided with H2 and L2 connection points, and an O2 sliding point is provided between the H2 and L2 connection points, the O2 connection point is connected to the H1 connection point, the O1 connection point is connected to the fusible plug 13 through the pipeline nine 25, the L1 connection point is connected to the pipeline three 19 through the pipeline six 22 and then merged into the oil tank 3, the H2 connection point is connected to the pipeline six 22, and the pipeline nine 25 is connected to the pipeline two 18.

[0016] Furthermore, a stop valve three 9 is provided between the pipeline five 21 and the pipeline six 22.

[0017] Furthermore, a pipeline seven 23 is provided between the pipeline one 17 and the pipeline six 22, and a pilot oil source safety valve 8 and a pressure reducing valve 10 are provided on the pipeline seven 23. A pipeline eight 24 is provided between the pilot oil source safety valve 8 and the pressure reducing valve 10, and a pilot pressure gauge two 12.3 is provided on the pipeline eight 24; wherein, the pipeline loop below the pressure reducing valve 10 is a high-pressure control loop, and the pipeline loop above the pressure reducing valve 10 is a low-pressure pilot control loop.

[0018] Furthermore, an air filter 1 is provided at the top end of the oil tank 3, and an oil suction filter 2 is provided at the bottom end.

[0019] Furthermore, the pipeline 17 is connected to a hydraulic actuator 16 .

[0020] Connect the ferrule connector on the hydraulic actuator to its self-acting hydraulic control mechanism. Under normal circumstances, that is, when the hydraulic control mechanism is not working (normal working pressure is 10-25Mpa), the hydraulically controlled safety valve is open; when the control actuator is working (that is, within the normal working pressure range), the safety valve is completely closed. Ensure the safe extraction and transmission of unconventional natural gas wells.

[0021] The specific equipment process steps are as follows: (1) Before the hydraulic control safety valve works normally, the hydraulic oil in the oil tank 3 is pumped into the high-pressure control circuit and the low-pressure pilot control circuit through the one-way valve 5 by the manual pump 4. The pressure in the high-pressure control circuit is maintained at about 35 MPa through the main oil source accumulator 11.1; the high-pressure control circuit introduces the hydraulic oil into the low-pressure pilot control circuit through the pressure reducing valve 10. The pilot oil source accumulator 11.2 of the low-pressure pilot control circuit maintains the pressure in the circuit at 5~20 MPa (adjustable). The pilot oil source safety valve 8 is installed in the low-pressure pilot circuit. When the manual pump 4 increases the pressure, the pressure is too high, the pilot oil source safety valve 8 in the low-pressure pilot control circuit opens, and the hydraulic oil flows back to the oil tank 3. The main oil source accumulator, pilot oil source accumulator and pilot oil source safety valve work together to ensure the stability of the oil pressure in the high and low pressure control circuits during the manual pump pressurization process and avoid large fluctuations in the oil pressure. At the same time, the oil pressure in the high pressure control circuit drives the hydraulic actuator 16 to compress the spring. The hydraulically controlled safety valve is in the open state under normal production conditions of the gas well, such as Figure 2 As shown, after ventilation and pressurization, the hydraulic actuator is in the initial state: hydraulic oil is filled in pipeline 1 17, pipeline 7 23, pipeline 8 24, and pipeline 9 25, and the main oil source accumulator 11.1 and the pilot oil source accumulator 11.2 are in the oil filling and pressure maintaining state; under normal working state, the stop valve 1 6.1 and the stop valve 3 9 are closed, the stop valve 2 6. is opened, the hydraulic pilot valve 7 and the pilot oil source safety valve 8 are closed, and the pressure reducing valve 10 is opened; (2) If Figure 3 As shown, when the pressure of the on-site gas source 15 is too low (lower than 0.8MPa), the low-pressure valve group in the low-pressure pilot control circuit works, H1 and O1 are connected, H2 and O2 are connected, and the hydraulic oil flows back to the oil tank 3 through the hydraulic oil pipeline in the actuator (the hydraulic oil unloads the hydraulic oil pressure in the low-pressure pilot control circuit through H2, O2, H1, O1, and pipeline 6 22, and the hydraulic oil flows back to the 3 oil tank. At the same time, the hydraulic pilot valve 7 is opened, and the hydraulic oil in the high-pressure control circuit flows back to the oil tank 3 through the stop valve 2 6.2 and the hydraulic pilot valve 7. The oil pressure in the main circuit is reduced, the hydraulic actuator spring is relaxed, and the valve is closed). The reduced oil pressure in the high-pressure control circuit drives the hydraulic actuator to work, the spring is relaxed, and the hydraulic control safety valve is closed; (3) If Figure 4As shown, when the on-site gas source pressure is too high (higher than 3.6MPa), the high-pressure valve group in the low-pressure pilot control circuit works, L1 is connected to O1, L2 is connected to O2, and the hydraulic oil flows back to the oil tank through the hydraulic oil pipeline in the actuator (the hydraulic oil unloads the hydraulic oil pressure in the low-pressure pilot control circuit through L1, O1, pipeline nine 25, and pipeline six 22, and the hydraulic oil flows back to the oil tank 3. At the same time, the hydraulic pilot valve 7 is opened, and the hydraulic oil in the high-pressure control circuit flows back to the oil tank 3 through the stop valve two 6.2 and the hydraulic pilot valve 7. The oil pressure in the main circuit is reduced, the hydraulic actuator spring is relaxed, and the valve is closed). The reduced oil pressure in the high-pressure control circuit drives the hydraulic actuator to work, the spring is relaxed, and the hydraulic control safety valve (hydraulic oil) is closed. (4) When the upstream and downstream gathering and transportation pipelines of the gas well need maintenance or pipeline modification, open the stop valve 6.1 to relieve the pressure of the high and low pressure control circuits. The hydraulic oil flows back to the oil tank through the valve, driving the hydraulic actuator to work, the spring expands, and the hydraulic control safety valve is closed; (5) When a fire occurs at the gas well production site, the fusible plug melts, the pilot oil source leaks out, the hydraulic pilot valve 7 opens, the hydraulic oil in the high-pressure control circuit flows into the oil tank, the control circuit is depressurized, the hydraulic actuator works, the spring expands, and the hydraulic safety valve is closed; (6) In case of an emergency on site, the stop valve 9 (ESD emergency valve) can be opened directly, the high and low pressure control circuits are depressurized, the hydraulic actuator works, the spring relaxes, and the hydraulically controlled safety valve is manually shut off in an emergency.

[0022] Through the orderly operation of the high and low pressure control circuits in the above-mentioned high-efficiency and energy-saving hydraulically controlled safety valve actuator, safe production of gas wells can be guaranteed around the clock and continuous gas supply to the downstream gathering and transportation pipeline network can be ensured.

Claims

1. A high-efficiency and energy-saving hydraulically controlled safety valve actuator, characterized in that: The invention comprises an oil tank (3), a high- and low-pressure valve group (14) and a fusible plug (13); a pipeline (17) is provided at one end of the bottom of the oil tank (3); a manual pump (4), a one-way valve (5), a main oil source accumulator (11.1) and a main oil source pressure gauge (12.1) are provided on the pipeline (17) in sequence; the high- and low-pressure valve group (14) is connected to an on-site gas source (15); and the fusible plug (13) is connected to a pilot oil source accumulator via a pipeline (18). (11.2) and pilot pressure gauge 1 (12.2), the top of the oil tank (3) is connected to pipeline 1 (17) through pipeline 3 (19), and stop valve 2 (6.2) and hydraulic pilot valve (7) are provided on pipeline 3 (19), pipeline 4 (20) is provided between pipeline 3 (19) and pipeline 1 (17), and stop valve 1 (6.1) is provided on pipeline 4 (20), and hydraulic pilot valve (7) is connected to pipeline 2 (18) through pipeline 5 (21).

2. According to claim 1, a high-efficiency and energy-saving hydraulically controlled safety valve actuator is characterized in that: The high-low pressure valve group (14) comprises a high-pressure valve group and a low-pressure valve group, wherein the high-pressure valve group is provided with a connection point H1 and an L1, and an O1 sliding point is provided between the connection points H1 and L1; the low-pressure valve group is provided with a connection point H2 and an L2, and an O2 sliding point is provided between the connection points H2 and L2, the O2 connection point is connected to the H1 connection point, the O1 connection point is connected to the fusible plug (13) via a pipeline nine (25), the L1 connection point is connected to a pipeline three (19) via a pipeline six (22), the H2 connection point is connected to the pipeline six (22), and the pipeline nine (25) is connected to the pipeline two (18).

3. The high-efficiency and energy-saving hydraulically controlled safety valve actuator according to claim 2 is characterized in that: A stop valve three (9) is provided between the pipeline five (21) and the pipeline six (22).

4. The high-efficiency and energy-saving hydraulically controlled safety valve actuator according to claim 3 is characterized in that: A pipeline seven (23) is provided between the pipeline one (17) and the pipeline six (22), a pilot oil source safety valve (8) and a pressure reducing valve (10) are provided on the pipeline seven (23), a pipeline eight (24) is provided between the pilot oil source safety valve (8) and the pressure reducing valve (10), and a pilot pressure gauge two (12.3) is provided on the pipeline eight (24); wherein the pipeline loop below the pressure reducing valve (10) is a high-pressure control loop, and the pipeline loop above the pressure reducing valve (10) is a low-pressure pilot control loop.

5. The high-efficiency and energy-saving hydraulically controlled safety valve actuator according to claim 1 is characterized in that: The top end of the oil tank (3) is provided with an air filter (1), and the bottom end is provided with an oil suction filter (2).

6. The high-efficiency and energy-saving hydraulically controlled safety valve actuator according to claim 1 is characterized in that: The pipeline 1 (17) is connected to a hydraulic actuator (16).

7. A method for using the high-efficiency and energy-saving hydraulically controlled safety valve actuator according to claim 1, characterized in that: The steps include: S1. Before the hydraulically controlled safety valve works normally, the hydraulic oil in the oil tank (3) is pumped into the high-pressure control circuit and the low-pressure pilot control circuit through the one-way valve (5) by the manual pump (4). The pressure in the high-pressure control circuit is maintained at 35 MPa through the main oil source accumulator (11.1); the high-pressure control circuit introduces the hydraulic oil into the low-pressure pilot control circuit through the pressure reducing valve (10). The pilot oil source accumulator (11.2) of the low-pressure pilot control circuit maintains the pressure in the circuit at 5-20 MPa. A pilot oil source safety valve (8) is installed in the low-pressure pilot circuit. When the manual pump (4) increases the pressure, the pressure is too high, the pilot oil source safety valve (8) in the low-pressure pilot control circuit opens, and the hydraulic oil flows back to the oil tank (3). At the same time, the oil pressure in the high-pressure control circuit drives the hydraulic actuator (16) to compress the spring. The hydraulically controlled safety valve is in the open state under normal production conditions of the gas well. S2. When the pressure of the on-site gas source (15) is lower than 0.8 MPa, the low-pressure valve group in the low-pressure pilot control circuit works, H2 and O2 are connected, H1 and O1 are connected, the hydraulic oil flows back to the oil tank (3), the oil pressure in the high-pressure control circuit decreases, driving the hydraulic actuator (16) to work, the spring expands, and the hydraulic control safety valve is closed; S3. When the on-site air source pressure is higher than 3.6 MPa, the high-pressure valve group in the low-pressure pilot control circuit works, L1 and O1 are connected, the hydraulic oil flows back to the oil tank (3), the oil pressure in the high-pressure control circuit decreases, driving the hydraulic actuator to work, the spring expands, and the hydraulic control safety valve is closed; S4. When the upstream and downstream gathering and transportation pipelines of the gas well need maintenance or pipeline reconstruction, the stop valve 1 (6.1) is opened to relieve the pressure of the high and low pressure control circuits. The hydraulic oil flows back into the oil tank (3) through the stop valve 1 (6.1), driving the hydraulic actuator (16) to work, the spring expands, and the hydraulic control safety valve is closed; S5. When a fire occurs at the gas well production site, the fusible plug (13) melts, the pilot oil source leaks out, the hydraulic pilot valve (7) opens, the hydraulic oil in the high-pressure control circuit flows into the oil tank (3), the control circuit is depressurized, the hydraulic actuator (16) works, the spring expands, and the hydraulic safety valve is closed; S6. In case of an emergency on site, the stop valve 3 (9) can be opened directly, the high and low pressure control circuits are depressurized, the hydraulic actuator (16) works, the spring expands, and the hydraulically controlled safety valve is manually shut off in an emergency.

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