Wellhead gas channeling prevention device and gas channeling prevention control method

Abstract

The wellhead gas channeling prevention device comprises a Christmas tree, a first oil extraction pipe is communicated with an oil pipe head of the Christmas tree, and a casing pipe blow-down pipe is communicated with a casing pipe head of the Christmas tree; a top port of the Christmas tree is connected with an oil pumping unit through an oil pumping rod, the free end of the first oil extraction pipe is connected with a three-way connector, the three-way connector is communicated with a second oil extraction pipe and an oil pipe blow-down pipe, the second oil extraction pipe is provided with an oil pipe electric valve and a first pressure transmitter, and the sleeve blow-down pipe is provided with a sleeve electric valve and a second pressure transmitter. The oil pipe electric valve, the first pressure transmitter, the sleeve electric valve and the second pressure transmitter are connected with a PLC control cabinet through wires, the PLC control cabinet is connected with an oil pumping unit control cabinet through a wire, the invention further discloses a gas channeling prevention control method of the wellhead gas channeling prevention device, a switch is turned on firstly, and control after data comparison is conducted through the PLC control cabinet; the problem that in the prior art, oil production wellhead pressure building piercing leakage easily causes environmental pollution accidents is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas well production, relates to a wellhead gas channeling prevention device, and further relates to a control method for the wellhead gas channeling prevention device. Background Art

[0002] At present, most water-driven oil reservoirs have entered the middle and late stages of development. The water content of the oil fields is high and the control degree of water drive is low. It is necessary to further improve the recovery rate of crude oil by carrying out tertiary oil recovery technology. Domestic and foreign practices have proved that natural gas drive has the advantages of small injection pressure difference, simple pre- and post-processing, no damage to the oil layer, no corrosion to pipelines, recyclable natural gas, and low operating costs. Natural gas drive can effectively improve the efficiency of oil recovery, thereby improving the recovery rate of crude oil; the recovery rate of miscible drive is 20-60%, and the recovery rate of immiscible drive is 8-13%. As an effective recovery technology, natural gas drive has been carried out in Changqing Oilfield for pilot tests and achieved good development results. At present, the pilot test of natural gas drive adopts the "one injection, multiple recovery, multiple injection, multiple recovery" technology, injecting natural gas into the oil layer through the ground injection system, using natural gas to drive oil, and then recovering oil through mechanical oil recovery technology.

[0003] During the natural gas injection process, due to the fracture channels formed by the previous water drive and the mutual communication of the natural fractures in the formation with the injection, multiple channels are formed between the injection well and the oil production well. Under the disturbance of the oil production process, part of the high-pressure injected natural gas enters the wellbore through the natural fracture channels during mechanical oil production, and the high-pressure natural gas rushes to the wellhead along with the crude oil. When the pressure increases, it sprays out from the seal of the oil pipe or casing mouth. The pressure buildup and leakage at the oil production wellhead can easily cause environmental pollution accidents; more seriously, the high-pressure natural gas and crude oil are transported along the oil production pipeline to the downstream oil and gas processing station, which may cause the downstream oil tanks and equipment to be sprayed at the least, and may cause damage to the oil and gas processing device or equipment, and the oil tank pressure buildup and explosion at the worst; the main method to solve the gas channeling is to increase the intensity of on-site inspections, observe the pressure of the oil production wellhead affected by the injection well through personnel, and manually release the pressure in time if the pressure increases, and automatic control and automatic pressure relief cannot be achieved. Summary of the invention

[0004] The purpose of the invention is to provide a wellhead gas channeling prevention device, which solves the problem of pressure build-up and leakage at the oil production wellhead existing in the prior art.

[0005] Another object of the present invention is to provide a control method for preventing gas channeling of a wellhead gas channeling prevention device.

[0006] The technical solution adopted by the present invention is to include an oil production tree, the oil pipe head of the oil production tree is connected to a first oil production pipe, and the casing head of the oil production tree is connected to a casing vent pipe; the top port of the oil production tree is connected to a pumping unit through a sucker rod, the free end of the first oil production pipe is connected to a three-way joint, the three-way joint is respectively connected to a second oil production pipe and a pipe vent pipe, the second oil production pipe is provided with an oil pipe electric valve and a first pressure transmitter, the casing vent pipe is provided with a casing electric valve and a second pressure transmitter, the oil pipe electric valve, the first pressure transmitter, the casing electric valve and the second pressure transmitter are respectively connected to a PLC control cabinet by wires, and the PLC control cabinet is connected to a pumping unit control cabinet by wires.

[0007] The present invention is also characterized in that:

[0008] A tubing valve is provided at the connection between the Christmas tree tubing head and the first production pipe, a casing valve is provided at the connection between the Christmas tree casing head and the casing vent pipe, and a vent pipe valve is provided at the tubing vent pipe.

[0009] The oil pipe electric valve and the first pressure transmitter are connected to the PLC control cabinet through the first control line, the casing electric valve and the second pressure transmitter are connected to the PLC control cabinet through the second control line, and the pumping unit control cabinet is connected to the PLC control cabinet through the third control line.

[0010] The free end of the tubing vent pipe is connected to the vent pool, and the free end of the casing vent pipe is connected to the vent pool.

[0011] The oil pumping unit is electrically connected to an oil pumping unit control cabinet.

[0012] The PLC control cabinet is wirelessly connected with an alarm.

[0013] Another technical solution adopted by the present invention is a control method for preventing gas channeling of a wellhead gas channeling prevention device, and the specific steps are as follows:

[0014] Step 1: Pre-set the high pressure limit in the PLC control cabinet; turn on the power switch and monitor the pressure in the pipe of the wellhead anti-gas channeling device;

[0015] Step 2: Based on the pressure inside the pipe obtained in step 1, the pressure information is transmitted to the PLC control cabinet in real time through the first pressure transmitter and the second pressure transmitter, and the PLC control cabinet determines whether the obtained pressure inside the pipe is higher than the high pressure limit; if the pressure inside the pipe is higher than the high pressure limit, an abnormality occurs, and the oil pipe electric valve, casing electric valve, and pumping unit control cabinet are controlled to be closed, and the alarm sounds an alarm at the same time.

[0016] The beneficial effects of the present invention are as follows: the wellhead anti-gas channeling device and the anti-gas channeling control method of the present invention, first, ensure the safety of oil well production, close the valve in time and shut down the pumping unit after gas channeling occurs, prevent the oil well from blowing out, reduce the oil and gas spraying outside the wellhead, and are beneficial to environmental protection; second, ensure the safety of downstream oil and gas pipelines and oil and gas processing stations, close the valve in time after gas channeling occurs, reduce the probability of damage to downstream oil and gas processing equipment and oil tank overflow; third, provide strong technical support for the large-scale development of gas drives such as natural gas drive and carbon dioxide drive in tertiary oil recovery. The invention improves oilfield production safety and reduces the labor intensity of inspection personnel; it solves the problem of environmental pollution accidents caused by pressure buildup and leakage at the oil wellhead in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of the wellhead gas channeling prevention device of the present invention.

[0018] Among them, 1. Christmas tree, 2. first production pipe, 3. casing vent pipe, 4. three-way joint, 5. second production pipe, 6. tubing vent pipe, 7. tubing electric valve, 8. first pressure transmitter, 9. first control line, 10. PLC control cabinet, 11. casing electric valve, 12. second pressure transmitter, 13. second control line, 14. third control line, 15. pumping unit control cabinet, 16. tubing valve, 17. casing valve, 18. vent pool, 19. alarm, 20. pumping unit, 21. vent pipe valve. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] The present invention provides a wellhead gas channeling prevention device, such as Figure 1As shown, it comprises an oil production tree 1, the tubing head of the oil production tree 1 is connected to a first oil production pipe 2, the casing head of the oil production tree 1 is connected to a casing vent pipe 3; the top port of the oil production tree 1 is connected to a pumping unit 20 through a sucker rod, the sucker rod passes through the top port of the oil production tree 1 and extends into it, the free end of the first oil production pipe 2 is connected to a tee joint 4, one end of the tee joint 4 is connected to a second oil production pipe 5, the other end of the tee joint 4 is connected to an oil pipe vent pipe 6, the second oil production pipe 5 is provided with an oil pipe electric valve 7 and a first pressure transmitter 8, the casing vent pipe 6 is connected to the second oil production pipe 5, and the casing vent pipe 6 is connected to the second oil production pipe 5. The empty pipe 3 is provided with a casing electric valve 11 and a second pressure transmitter 12. The oil pipe electric valve 7 and the first pressure transmitter 8 are respectively connected to a PLC control cabinet 10 through a first control line 9, and the casing electric valve 11 and the second pressure transmitter 12 are respectively connected to the PLC control cabinet 10 through a second control line 13. The PLC control cabinet 10 is connected to a pumping unit control cabinet 15 through a third control line 14. The pumping unit control cabinet 15 is connected to a pumping unit 20. The oil pipe head of the Christmas tree 1 is connected to the first oil production pipe. 2 is provided with a tubing valve 16, a casing valve 17 is provided at the connection between the casing head of the Christmas tree 1 and the casing vent pipe 3, a vent pipe valve 21 is provided on the tubing vent pipe 6, the other end of the tubing vent pipe 6 is connected with a vent pool 18, the free end of the casing vent pipe 3 is connected with the vent pool 18, and the PLC control cabinet 10 is wirelessly connected with the alarm 19 in the duty room; the PLC control cabinet 10 can automatically control the casing electric valve 11, the pumping unit control cabinet 15, the alarm 19 and the tubing electric valve 7. When gas leakage occurs, the control casing electric valve 11, the oil pipe electric valve 7 and the pumping unit control cabinet 15 are closed and stop working, and the pressure in the pipe will not increase. When the staff in the duty room hear the alarm 19, they will immediately go to the scene to test where the pressure in the pipe is strong, open the corresponding vent pipe valve to release the pressure, and discharge the excess pressure in the pipe into the vent pool. The present invention realizes that when gas leakage occurs, emergency safety measures are taken at the first time through the PLC control cabinet 10, thereby ensuring the safety of oil production.

[0021] During normal operation, the first pressure transmitter 8 and the second pressure transmitter 12 transmit the pressure value in the pipe to the PLC control cabinet 10 through wires for real-time monitoring. The produced oil and gas flow into the downstream oil tank or booster station through the first oil production pipe 2 and the second oil production pipe 5. The vent pipe valve 21 is in a closed state, and the oil pipe electric valve 7 and the casing electric valve 11 are in an open state.

[0022] The control method of the wellhead gas channeling prevention device is as follows:

[0023] Step 1: pre-set the high pressure limit in the PLC control cabinet 10; turn on the power switch and monitor the pressure in the pipe of the wellhead anti-gas channeling device.

[0024] Step 2: Based on the pressure inside the pipe obtained in step 1, the pressure information is transmitted to the PLC control cabinet 10 in real time through the first pressure transmitter 8 and the second pressure transmitter 12, and the PLC control cabinet 10 determines whether the obtained pressure inside the pipe is higher than the high pressure limit; if the pressure inside the pipe is higher than the high pressure limit, an abnormality occurs, and the oil pipe electric valve 7, the casing electric valve 11, and the pumping unit control cabinet 15 are controlled to be closed, and the alarm 19 sounds an alarm.

[0025] When gas channeling occurs, if the pressure in the second oil production pipe 5 increases, the first pressure transmitter 8 transmits the measured pressure signal to the PLC control cabinet 10 through the first control line 9 in real time, and the pressure value is compared with the high pressure limit set in the PLC control cabinet 10. If it exceeds the high limit, the PLC control cabinet 10 controls the oil pipe electric valve 7, the casing electric valve 11 and the pumping unit control cabinet to close and controls the alarm 19 to sound after receiving the signal; if the pressure in the casing vent pipe 3 increases, the second pressure transmitter 12 transmits the signal to the PLC control cabinet 10, and the pressure value is compared with the high pressure limit set in the PLC control cabinet 10. If it exceeds the high limit, the PLC control cabinet 10 receives the signal. Then control the oil pipe electric valve 7, casing electric valve 11 and the pumping unit control cabinet to close and control the alarm 19 to sound. After receiving the alarm information, the staff immediately rushes to the scene to deal with it. The operator closes the oil pipe valve 16 and the casing valve 17 after arriving at the scene as soon as possible, and then determines whether the oil pipe pressure or the casing pressure is abnormal by pressure. If the oil pipe pressure is abnormal, start to slowly open the oil pipe valve 16 and the vent pipe valve 21, and the oil and gas are discharged into the vent pool 18 through the oil pipe vent pipe 6 to eliminate the fault; if the casing pressure is abnormal, start to slowly open the casing valve 17 and the casing electric valve 11, and the oil and gas are discharged into the vent pool 18 through the casing vent pipe 4 line, eliminate the fault and resume production.

[0026] Example 1

[0027] In the wellhead anti-gas channeling device, when gas channeling occurs, the gas mixed with oil and gas is ejected through the oil pipe, flowing through the oil pipe valve 16 and the oil pipe electric valve 7, and the first pressure transmitter 8 transmits the pressure abnormality signal to the PLC control cabinet 10; when gas channeling occurs, the gas is ejected through the casing, flowing through the casing valve 17 and the casing electric valve 11, and the second pressure transmitter 12 transmits the pressure abnormality signal to the PLC control cabinet 10; the PLC control cabinet 10 identifies the monitored pressure signal, and then transmits the operation signal through the wire to the oil pipe electric valve 7, the casing electric valve 11 and the pumping unit control cabinet 15 to realize the closing action, so as to keep the wellhead The oil pipe is in a completely closed state, and at the same time, the PLC control cabinet 10 wirelessly transmits the alarm signal to the alarm 19 for alarm; after hearing the alarm signal, the staff rushes to the scene to make a judgment. If it is judged that the oil pipe pressure has gas leakage, the oil pipe valve 16 and the vent pipe valve 21 are opened to discharge the oil and gas in the oil pipe to the vent pool 18, release the high-pressure oil and gas or take well killing operations to eliminate the gas leakage fault and resume production; if it is judged that the casing pressure has gas leakage, the casing valve 17 and the casing electric valve 11 are opened to discharge the oil and gas in the casing to the vent pool 18, release the high-pressure oil and gas or take well killing operations to eliminate the gas leakage fault and resume production.

[0028] Example 2

[0029] The wellhead gas channeling prevention device comprises an oil production tree 1, the oil pipe head of the oil production tree 1 is connected to a first oil production pipe 2, and the casing head of the oil production tree 1 is connected to a casing vent pipe 3; the top port of the oil production tree 1 is connected to a pumping unit 20 through a sucker rod, the free end of the first oil production pipe 2 is connected to a three-way joint 4, and the three-way joint 4 is respectively connected to a second oil production pipe 5 and an oil pipe vent pipe 6, the second oil production pipe 5 is provided with an oil pipe electric valve 7 and a first pressure transmitter 8, the casing vent pipe 3 is provided with a casing electric valve 11 and a second pressure transmitter 12, the oil pipe electric valve 7, the first pressure transmitter 8, and the casing electric valve 11 are connected to the oil production pipe 20, and the oil production pipe electric valve 7, the first pressure transmitter 8, and the casing electric valve 11 are connected to the oil production pipe 20. The second pressure transmitter 12 is connected to the PLC control cabinet 10 by wires, and the PLC control cabinet 10 is connected to the oil pump control cabinet 15 by wires; based on the calculation that the loss of crude oil in a single gas channeling is 10 tons / day, 3 tons of waste oil treatment and 2 days of environmental recovery, the loss caused by a gas channeling is about 500,000 yuan; with the increase in the scale of gas drive development, the possibility of gas channeling gradually increases. According to the estimation of 100 wells, the cumulative direct cost in the next 3-5 years will be about 50 million yuan. At the same time, the application of the invention reduces the generation of waste oil and sewage, which is beneficial to the environmental protection of oil and gas fields.

[0030] Example 3

[0031] The wellhead gas channeling prevention device comprises an oil production tree 1, the oil production tree 1 tubing head is connected to a first oil production pipe 2, and the casing head of the oil production tree 1 is connected to a casing vent pipe 3; the top port of the oil production tree 1 is connected to an oil pump 20 through a sucker rod, the free end of the first oil production pipe 2 is connected to a three-way joint 4, the three-way joint 4 is respectively connected to a second oil production pipe 5 and an oil pipe vent pipe 6, the second oil production pipe 5 is provided with an oil pipe electric valve 7 and a first pressure transmitter 8, and the casing vent pipe 3 is provided with a casing electric valve 1 1 and the second pressure transmitter 12, the tubing electric valve 7, the first pressure transmitter 8, the casing electric valve 11 and the second pressure transmitter 12 are respectively connected to the PLC control cabinet 10 by wires, and the PLC control cabinet 10 is connected to the pumping unit control cabinet 15 by wires; a tubing valve 16 is provided at the connection between the tubing head of the Christmas tree 1 and the first oil production pipe 2, a casing valve 17 is provided at the connection between the casing head of the Christmas tree 1 and the casing vent pipe 3, and a vent pipe valve 21 is provided at the tubing vent pipe 6.

[0032] Example 4

[0033] The control method of the wellhead gas channeling prevention device is as follows:

[0034] Step 1: pre-set the high pressure limit in the PLC control cabinet 10; turn on the power switch and monitor the pressure in the pipe of the wellhead anti-gas channeling device.

[0035] Step 2: Based on the pressure inside the pipe obtained in step 1, the pressure information is transmitted to the PLC control cabinet 10 in real time through the first pressure transmitter 8 and the second pressure transmitter 12, and the PLC control cabinet 10 determines whether the obtained pressure inside the pipe is higher than the high pressure limit; if the pressure inside the pipe is higher than the high pressure limit, an abnormality occurs, and the oil pipe electric valve 7, the casing electric valve 11, and the pumping unit control cabinet 15 are controlled to be closed, and the alarm 19 sounds an alarm at the same time.

Claims

1. Wellhead gas channeling prevention device, It is characterized in that The invention comprises a Christmas tree (1), wherein the Christmas tree (1) tubing head is connected to a first Christmas tree (2), and the Christmas tree (1) casing head is connected to a casing venting pipe (3); the top port of the Christmas tree (1) is connected to a pumping unit (20) via a sucker rod; the free end of the first Christmas tree (2) is connected to a three-way joint (4), and the three-way joint (4) is respectively connected to a second Christmas tree (5) and a Christmas tree venting pipe (6); the second Christmas tree (5) is provided with a Christmas tree electric valve (7) and a first pressure transmitter (8); the casing venting pipe (3) is provided with a casing electric valve (11) and a second pressure transmitter (12); the Christmas tree electric valve (7), the first pressure transmitter (8), the casing electric valve (11) and the second pressure transmitter (12) are respectively connected to a PLC control cabinet (10) by wires, and the PLC control cabinet (10) is connected to a pumping unit control cabinet (15) by wires.

2. The wellhead gas channeling prevention device according to claim 1, It is characterized in that A tubing valve (16) is provided at the connection between the tubing head of the Christmas tree (1) and the first production pipe (2), a casing valve (17) is provided at the connection between the casing head of the Christmas tree (1) and the casing vent pipe (3), and a vent pipe valve (21) is provided at the tubing vent pipe (6).

3. The wellhead gas channeling prevention device according to claim 2, It is characterized in that The oil pipe electric valve (7) and the first pressure transmitter (8) are respectively connected to the PLC control cabinet (10) via a first control line (9), the casing electric valve (11) and the second pressure transmitter (12) are respectively connected to the PLC control cabinet (10) via a second control line (13), and the pumping unit control cabinet (15) is connected to the PLC control cabinet (10) via a third control line (14).

4. The wellhead gas channeling prevention device according to claim 3, It is characterized in that The free end of the oil pipe vent pipe (6) is connected to the vent tank (18), and the free end of the casing vent pipe (3) is connected to the vent tank (18).

5. The wellhead gas channeling prevention device according to claim 4, It is characterized in that The oil pumping unit (20) is electrically connected to an oil pumping unit control cabinet (15).

6. The wellhead gas channeling prevention device according to claim 5, It is characterized in that The PLC control cabinet (10) is wirelessly connected to an alarm (19).

7. The control method for preventing gas channeling of a wellhead gas channeling prevention device according to any one of claims 1 to 6, wherein the specific steps are as follows: Step 1: pre-set the high pressure limit in the PLC control cabinet (10); turn on the power switch and monitor the pressure in the pipe of the wellhead anti-gas channeling device; Step 2: Based on the pressure inside the pipe obtained in step 1, the pressure information is transmitted to the PLC control cabinet (10) in real time through the first pressure transmitter (8) and the second pressure transmitter (12), and the PLC control cabinet (10) determines whether the pressure inside the pipe obtained is higher than the upper pressure limit; if the pressure inside the pipe is higher than the upper pressure limit, an abnormality occurs, and the oil pipe electric valve (7), the casing electric valve (11), and the pumping unit control cabinet (15) are controlled to be closed, and the alarm (19) sounds an alarm at the same time.

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