Wellbore liquid level continuous monitoring device and method for workover treatment and workover assembly

Abstract

The invention discloses a shaft liquid level continuous monitoring device for workover treatment, and relates to the technical field of gas well workover treatment, the shaft liquid level continuous monitoring device comprises a gas pipeline, a gas supply assembly, a sound wave receiver and a control system, one end of the gas pipeline is connected with an oil pipe sealing joint, the other end of the gas pipeline is connected with the gas supply assembly, the oil pipe sealing joint is connected with an oil pipe, and the gas supply assembly provides gas; the gas is instantaneously expanded at the joint of the gas pipeline and the oil pipe to form an infrasound pulse shock wave, the infrasound pulse shock wave is spread to the underground along the oil pipe and is reflected when encountering the surface of well killing fluid, the sound wave receiver can receive the reflected infrasound pulse shock wave, and the control system calculates the liquid level in the oil pipe according to a signal transmitted by the sound wave receiver. The shaft liquid level is obtained. The invention further provides a monitoring method based on the shaft liquid level continuous monitoring device for well repair operation and a well repair assembly. According to the invention, the liquid level in the oil pipe can be quickly and conveniently tested in the process of pulling out the oil pipe, so that the liquid level in an underground shaft is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of workover operations for gas wells, and particularly to a device, method, and workover assembly for continuously monitoring the liquid level in a wellbore during workover operations. Background Art

[0002] During the workover process in oil and gas fields, the problem of downhole leakage often occurs. Especially during the workover operation of gas wells, when the pressure-sensitive formation has active oil and gas, the phenomenon of "both leakage and overflow" is likely to occur. To ensure well control safety and protect the oil and gas reservoir, it is necessary to scientifically and reasonably inject kill fluid into the well. However, there is a safety window for the pressure of the workover kill fluid. When the pressure of the kill fluid is less than the formation pressure, well kick may occur, and in severe cases, blowout may occur; when the pressure of the kill fluid is greater than the formation pressure, well leakage may occur, and in severe cases, major leakage may occur.

[0003] Due to the unclear understanding of the dynamic changes of the downhole liquid level, it is difficult to control the injection volume of the kill fluid with a reasonable downhole liquid level. Without the condition of liquid level monitoring, in order to ensure well control safety and control the upward flow rate of the fluid, only high-density excessive kill fluid can be used for perfusion.

[0004] During the workover operation of gas wells, well kick or well leakage is most likely to occur during tripping or pulling out the tubing. Therefore, during the tripping process, it is necessary to continuously monitor the height of the liquid level in the wellbore, inject kill fluid according to the liquid level height, and timely control leakage and prevent blowout.

[0005] The problems existing in the existing drilling and workover liquid level testing equipment and technologies are mainly manifested in:

[0006] During the process of pulling out the tubing string, it is necessary to inject kill fluid, and at this time, the blowout preventer must be opened and the throttle manifold valve must be closed; while the existing technical equipment is usually installed at the J8 port of the throttle manifold, and the test valve needs to be opened and the blowout preventer needs to be closed during the test, so continuous testing cannot be achieved during the injection of kill fluid and the pulling out of the tubing.

[0007] Another installation position of the existing technical equipment is at the large four-way joint of the wellhead. Due to the influence of the wellhead open end and the overflow port, a large part of the test signal energy is lost, and the test effect is unstable; during the test during tripping, the wellbore interference is large, and the test success rate is very low.

[0008] Therefore, during the workover operation, there is an urgent need to monitor the change of the liquid level in the wellbore annulus in real time and accurately, so as to provide effective technical support for effective plugging and well control safety. Summary of the Invention

[0009] The object of the present invention is to provide a wellbore liquid level continuous monitoring device, method and workover assembly for workover operations, so as to solve the problems existing in the above-mentioned prior art, be able to quickly and conveniently test the liquid level in the tubing during the process of pulling out the tubing, thereby obtaining the liquid level in the downhole wellbore, and also be able to ensure that the test can be carried out at any time.

[0010] To achieve the above object, the present invention provides the following solutions:

[0011] The present invention provides a wellbore liquid level continuous monitoring device for workover operations, including an air pipeline, a gas supply assembly, a sound wave receiver and a control system. One end of the air pipeline is connected with a tubing sealing joint, and the other end is connected with the gas supply assembly. The tubing sealing joint is used for connecting with the tubing; the gas supply assembly includes a constant pressure tank and a booster. The constant pressure tank is filled with high-pressure gas, and the outlet of the constant pressure tank is connected with an outlet pipeline. The outlet pipeline is connected with the air pipeline, and a pulse valve is further arranged on the outlet pipeline. The pulse valve is in signal connection with the control system; the booster is connected with the constant pressure tank and can boost the pressure of the constant pressure tank, and the booster is in signal connection with the control system;

[0012] The gas supply assembly is used to provide gas and cause the gas to instantaneously expand at the connection of the air pipeline and the tubing, forming a infrasonic pulse shock wave. The infrasonic pulse shock wave can propagate downhole along the tubing, reflect when encountering the surface of the kill fluid, the sound wave receiver can receive the reflected infrasonic pulse shock wave, and the sound wave receiver is in signal connection with the control system. The control system can calculate the wellbore liquid level according to the data transmitted by the sound wave receiver.

[0013] Preferably, a conical part is arranged on the tubing sealing joint. The conical part is used to extend into the tubing, and the tubing sealing joint is made of an elastic material.

[0014] Preferably, a wireless button switch is further arranged on the tubing sealing joint. The wireless button switch is wirelessly connected with the control system.

[0015] Preferably, the length of the air pipeline is 2 - 10 meters, and the diameter of the air pipeline is 8 - 12 millimeters.

[0016] Preferably, it further includes a field display screen. The field display screen is used to be arranged on the driller's console, and the field display screen is in signal connection with the control system;

[0017] It further includes a wireless antenna. The wireless antenna is in signal connection with the control system, and the wireless antenna is used for wireless connection with a remote server.

[0018] Preferably, it further includes an explosion-proof control box which is used to be placed on the second-layer platform, and the control system, the air supply component and the acoustic wave receiver are all arranged in the explosion-proof control box.

[0019] Preferably, one end of the gas pipeline is connected to the oil pipe sealing joint through a first quick connector, and the other end of the gas pipeline is connected to one end of the outlet pipeline far away from the constant pressure tank through a second quick connector.

[0020] The present invention also provides a method for continuously monitoring the wellbore liquid level during workover operations, which is implemented by using the wellbore liquid level continuous monitoring device for workover operations as described above, and includes the steps:

[0021] S1. Connect the oil pipe sealing joint to the oil pipe opening of the oil pipe that has not been pulled out of the well.

[0022] S2. Start the air supply component to provide gas, and make the gas instantaneously expand at the connection of the gas pipeline and the oil pipe to form a infrasonic pulse shock wave. The infrasonic pulse shock wave propagates downward along the oil pipe, reflects when encountering the surface of the kill fluid, and the acoustic wave receiver receives the reflected infrasonic pulse shock wave and transmits the signal to the control system.

[0023] S3. The control system calculates the liquid level in the oil pipe according to the signal transmitted by the acoustic wave receiver, and the wellbore liquid level is the same as the liquid level in the oil pipe.

[0024] Preferably, after the step S3, it further includes the step:

[0025] S4. The operator takes out and stacks the oil pipes from the well. During this process, repeat the steps S1 to S3 until all tests are completed.

[0026] The present invention also provides a workover assembly, which includes the wellbore liquid level continuous monitoring device for workover operations as described above.

[0027] The present invention has achieved the following technical effects compared with the prior art:

[0028] In the present invention, according to the actual on-site situation of well workover liquid level testing, the wellbore liquid level continuous monitoring device for workover operations is set on the second-layer platform of the workover operation, and the liquid level change in the wellbore is obtained by testing the liquid level in the oil pipe, avoiding the drawbacks existing in the prior art when testing at the oil well wellhead or throttle manifolds and kill manifolds. The present invention eliminates the interference of wellbore vibration during the testing process, and does not require opening and closing valves during testing, simplifying the testing process; the testing acoustic wave energy has no loss, improving the reliability of the testing; avoiding the overflow of the kill fluid into the device and causing damage to the device; moreover, in the present invention, the downhole liquid level can be tested once for each oil pipe pulled out, realizing real-time continuous testing and ensuring well control safety.

[0029] Furthermore, a booster is provided in the present invention. The booster is connected to the constant pressure tank and can boost the pressure of the constant pressure tank. The booster is also signal-connected to the control system, and automatically boosts the pressure of the constant pressure tank under the control of the control system, so that a sufficient test pressure is always maintained in the constant pressure tank, ensuring that tests can be carried out at any time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 It is a schematic structural diagram of a well workover operation wellbore liquid level continuous monitoring device in an embodiment of the present invention;

[0032] Figure 2 It is a working installation schematic diagram of a well workover operation wellbore liquid level continuous monitoring device in an embodiment of the present invention.

[0033] In the figure: 1 - tubing seal joint, 2 - gas pipeline, 3 - explosion-proof control box, 4 - on-site display screen, 5 - wireless push button switch, 6 - first quick connector, 7 - second quick connector, 8 - acoustic wave receiver, 9 - pulse valve, 10 - constant pressure tank, 11 - booster, 12 - control system, 13 - power module, 14 - wireless antenna, 15 - control cable; 101 - workover truck; 102 - driller's console; 103 - tubing port; 104 - second floor platform; 105 - blowout preventer; 106 - overflow pipe; 107 - choke manifold; 108 - walkway ladder; 109 - kill fluid pit; 110 - casing; 111 - wellbore; 112 - tubing; 113 - wellhead cross; 114 - kill line; 115 - wellbore liquid level. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] The object of the present invention is to provide a well workover operation wellbore liquid level continuous monitoring device, method and workover assembly to solve the problems existing in the prior art, which can quickly and conveniently test the liquid level in the tubing during the process of pulling out the tubing, so as to obtain the liquid level in the downhole wellbore, and can also ensure that the test can be carried out at any time.

[0036] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Embodiment 1

[0038] As Figures 1 to 2 shown, in this embodiment, a well workover operation wellbore liquid level continuous monitoring device is provided, which can be used in well workover tripping operations. It mainly includes an air pipeline 2, an air supply assembly, an acoustic wave receiver 8 and a control system 12. One end of the air pipeline 2 is connected with a tubing sealing joint 1, and the other end is connected with the air supply assembly. The tubing sealing joint 1 is used to connect with the tubing port 103 of the tubing 112. The air supply assembly is used to provide gas, and the gas can generate an instantaneous expansion at the connection of the air pipeline 2 and the tubing 112 to form a infrasonic pulse shock wave. The infrasonic pulse shock wave can propagate downhole along the tubing 112, and is reflected when encountering the surface of the kill fluid. The acoustic wave receiver 8 can receive the infrasonic pulse shock wave, and the acoustic wave receiver 8 is signal-connected with the control system 12, and can transmit the relevant signals of the infrasonic pulse shock wave to the control system. The control system 12 can automatically analyze and calculate the received data, and automatically calculate the depth of the downhole liquid level from the ground wellhead through the propagation speed of the infrasonic pulse shock wave and the reflection time of the reflected pulse, completing the entire test process.

[0039] Since the downhole end of the tubing 112 of the gas well is in the form of a bell mouth, through the principle of the U-shaped tube communicating vessel, it can be known that the annulus liquid level in the downhole wellbore 111 is basically the same as the liquid level in the tubing 112. Measuring the liquid level in the tubing 112 means measuring the liquid level in the wellbore 111. In this embodiment, according to the actual situation of the well workover liquid level test on site, the well workover operation wellbore liquid level continuous monitoring device is arranged on the second layer platform 104 of the well workover operation, and the liquid level change in the wellbore 111 is obtained by testing the liquid level in the tubing 112, avoiding the disadvantages existing in the prior art when testing at the oil well wellhead or at the choke manifold 107 and kill line 114. This embodiment eliminates the vibration interference of the wellbore 111 during the test process, and does not require opening and closing valves during the test, simplifying the test process; the test acoustic wave energy has no loss, improving the reliability of the test; avoiding the overflow of the kill fluid into the device and causing damage to the device; moreover, in this embodiment, the downhole liquid level can be tested once every time a tubing 112 is pulled out, realizing real-time continuous testing and ensuring well control safety.

[0040] In this embodiment, a conical portion is provided on the tubing sealing joint 1. The conical portion is used to extend into the tubing 112. The tubing sealing joint 1 is made of an elastic material. The connection and sealing with the tubing 112 are achieved through the taper, and it can adapt to different sizes of the tubing 112. Threaded connection is not required, which facilitates quick installation and disassembly. As a preferred embodiment, the tubing sealing joint 1 is made of rubber material.

[0041] Alternatively, other conical portions can also be selected according to needs. For example, a support rod can be axially provided in the middle of the side of the tubing sealing joint 1 close to the tubing 112. A plurality of arc-shaped blocks are arranged around the support rod to form a conical structure. Springs are provided between the arc-shaped blocks and the support rod. The conical portion can be extended into the tubing 112 by compressing the springs, and the arc-shaped blocks can be fixed to the tubing 112 by the resilience of the springs.

[0042] In this embodiment, a wireless button switch 5 is further provided on the tubing sealing joint 1. The wireless button switch 5 is wirelessly connected to the control system 12. After the operator installs the tubing sealing joint 1, when the wireless button switch 5 is pressed, after the control system 12 inside the explosion-proof control box 3 receives the device connection completion signal of the wireless button switch 5, the test is immediately started.

[0043] In this embodiment, the length of the air pipeline 2 can be arbitrarily set according to the actual situation on site, preferably 2 to 10 meters, and the diameter of the air pipeline 2 is between 8 and 12 millimeters. There is a cross-sectional area difference of more than 20 times between the air pipeline 2 and the tubing 112, so that high-pressure gas can instantaneously expand at the connection between the air pipeline 2 and the tubing 112 to form a infrasonic pulse shock wave.

[0044] In this embodiment, a field display screen 4 is further included. The field display screen 4 is used to be arranged on the driller's console 102, and the field display screen 4 is signal-connected to the control system 12, and can report the test results and warning information to the driller in the first time. The driller is the first responsible person for the safety of the workover operation, responsible for commanding and coordinating all links of the workover operation on site, and achieving timely control of the leakage and well kick safety risks of the workover operation; further, a wireless antenna 14 is further included. The wireless antenna 14 is signal-connected to the control system 12. Through the wireless antenna 14, the test results and warning information can be transmitted to a remote server for remote monitoring through a mobile phone or a computer.

[0045] In this embodiment, an explosion-proof control box 3 is further included. The explosion-proof control box 3 is used to be placed on the second-layer platform 104. The control system 12, the gas supply assembly, and the acoustic wave receiver 8 are all arranged in the explosion-proof control box 3, and the wireless antenna 14 is arranged outside the explosion-proof control box 3. Further, a power supply module 13 is also arranged in the explosion-proof control box 3 for supplying power to the entire device.

[0046] In this embodiment, the gas supply assembly mainly includes a constant-pressure tank 10 filled with high-pressure gas. An outlet pipeline is connected to the outlet of the constant-pressure tank 10. One end of the outlet pipeline far from the constant-pressure tank 10 extends out of the explosion-proof control box 3. A pulse valve 9 is also arranged on the outlet pipeline, and the pulse valve 9 is in signal connection with the control system 12. Starting the pulse valve 9 can quickly release the high-pressure gas in the constant-pressure tank 10 into the oil pipe 112 through the gas pipeline 2. When the opening test of the pulse valve 9 is completed, it is immediately closed.

[0047] In this embodiment, the gas supply assembly further includes a booster 11 connected to the constant-pressure tank 10, which can boost the pressure of the constant-pressure tank 10. The booster 11 is in signal connection with the control system 12. The booster 11 automatically boosts the pressure of the constant-pressure tank 10 under the control of the control system 12, so that the constant-pressure tank 10 always maintains sufficient test pressure to ensure that tests can be carried out at any time.

[0048] In this embodiment, the control system 12 can be connected to the acoustic wave receiver 8, the pulse valve 9, the booster 11, the on-site display screen 4, the wireless antenna 14, etc. through a control cable 15.

[0049] In this embodiment, one end of the gas pipeline 2 is connected to the oil pipe sealing joint 1 through a first quick-connect joint 6, and the other end of the gas pipeline 2 is connected to one end of the outlet pipeline of the constant-pressure tank 10 extending out of the explosion-proof control box 3 through a second quick-connect joint 7, which facilitates the connection and disassembly of the gas pipeline 2 with the oil pipe sealing joint 1 and the explosion-proof control box 3. The gas pipeline 2 can be quickly removed when transporting the device.

[0050] The oil pipe sealing joint 1 adopting the above connection method in this embodiment has simple installation operation, and the well repair worker can easily complete the test, reducing the use threshold of the device and achieving cost reduction and efficiency improvement.

[0051] The working method of the wellbore liquid level continuous monitoring device for well repair operations in this embodiment is as follows:

[0052] First, the operator takes advantage of the gap when stacking the tubing 112 after pulling out one tubing 112 from the wellbore. Through pulling the gas pipeline 2, the tubing sealing joint 1 is docked to the port of the tubing 112 that has not been pulled out, and then the wireless push-button switch 5 on the tubing sealing joint 1 is pressed. After the control system 12 in the explosion-proof control box 3 receives the wireless start signal, it starts the pulse valve 9, and quickly releases the high-pressure gas in the constant-pressure tank 10 into the tubing 112 through the gas pipeline 2. There is a cross-sectional area difference of more than 20 times between the gas pipeline 2 and the tubing 112. The high-pressure gas instantaneously expands at the connection of the gas pipeline 2 and the tubing 112, forming an infrasonic pulse shock wave. This sound wave propagates downward along the tubing 112, reflects when encountering the surface of the kill fluid, and the reflected sound wave is received by the sound wave receiver 8. The control system 12 automatically analyzes and calculates the received data, and automatically calculates the depth of the downhole liquid level from the ground wellhead through the propagation speed of the sound wave pulse and the reflection time of the reflected pulse, completing the entire test process. Then the depth measurement result is displayed on the on-site display screen 4 on the driller's console 102.

[0053] Among them, the propagation speed of sound waves in the air is generally about 340 m / s under normal circumstances. The propagation distance in 10 seconds is 3400 meters, that is, the well depth within 1700 meters can be tested in 10 seconds. Since the depth of the kill fluid in the workover well is basically less than 2000 meters, after the on-site operator docks the tubing sealing joint 1 and presses the wireless push-button switch 5 for more than ten seconds, the tubing sealing joint 1 can be removed and placed beside the operation console for the next use. Thus, an effective test is completed. The entire test process does not exceed 30 seconds. Then normal workover operations can continue.

[0054] In this embodiment, a workover assembly is also provided, including the wellbore liquid level continuous monitoring device for workover operations as described above.

[0055] In the present invention, specific examples are used to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A wellbore liquid level continuous monitoring device for workover operations, characterized in that: It includes an air pipeline, a gas supply assembly, a sound wave receiver and a control system. One end of the air pipeline is connected with an oil pipe sealing joint, and the other end is connected with the gas supply assembly. The oil pipe sealing joint is used for connecting with an oil pipe; the gas supply assembly includes a constant pressure tank and a booster. The constant pressure tank is filled with high-pressure gas, and an outlet pipeline is connected to the outlet of the constant pressure tank. The outlet pipeline is connected with the air pipeline, and a pulse valve is further arranged on the outlet pipeline. The pulse valve is in signal connection with the control system; the booster is connected with the constant pressure tank and can boost the pressure of the constant pressure tank, and the booster is in signal connection with the control system; The gas supply assembly is used for providing gas and causing the gas to instantaneously expand at the connection between the air pipeline and the oil pipe to form a infrasonic pulse shock wave. The infrasonic pulse shock wave can propagate downward into the well along the oil pipe, and is reflected when encountering the surface of the kill fluid. The sound wave receiver can receive the reflected infrasonic pulse shock wave, and the sound wave receiver is in signal connection with the control system. The control system can calculate the wellbore liquid level according to the data transmitted by the sound wave receiver.

2. The well workover operation wellbore liquid level continuous monitoring device according to claim 1, characterized in that: A conical part is arranged on the oil pipe sealing joint. The conical part is used for extending into the oil pipe, and the oil pipe sealing joint is made of an elastic material.

3. The wellbore liquid level continuous monitoring device for workover operations according to claim 1 or 2, characterized in that: A wireless button switch is further arranged on the oil pipe sealing joint. The wireless button switch is wirelessly connected with the control system.

4. The wellbore liquid level continuous monitoring device for workover operations according to claim 1, characterized in that: The length of the air pipeline is 2 to 10 meters, and the diameter of the air pipeline is 8 to 12 millimeters.

5. The wellbore liquid level continuous monitoring device for workover operations according to claim 1, wherein: It further includes a field display screen. The field display screen is used for being arranged on the driller's console, and the field display screen is in signal connection with the control system; It further includes a wireless antenna. The wireless antenna is in signal connection with the control system, and the wireless antenna is used for wirelessly connecting with a remote server.

6. The wellbore liquid level continuous monitoring device for workover operations according to claim 1, wherein: It further includes an explosion-proof control box. The explosion-proof control box is used for being placed on the second floor platform. The control system, the gas supply assembly and the sound wave receiver are all arranged in the explosion-proof control box.

7. The wellbore liquid level continuous monitoring device for workover operations according to claim 1, characterized in that: One end of the air pipeline is connected with the oil pipe sealing joint through a first quick-connect joint, and the other end of the air pipeline is connected with the end of the outlet pipeline far away from the constant pressure tank through a second quick-connect joint.

8. A method for continuously monitoring the wellbore liquid level during workover operations, characterized in that: Implementing by using the well workover operation wellbore liquid level continuous monitoring device according to any one of claims 1-7, including the steps: S1. Connect the oil pipe sealing joint to the oil pipe opening of the oil pipe that has not been pulled out; S2. Turn on the gas supply assembly to provide gas, and cause the gas to instantaneously expand at the connection between the air pipeline and the oil pipe to form an infrasonic pulse shock wave. The infrasonic pulse shock wave propagates downward into the well along the oil pipe, is reflected when encountering the surface of the kill fluid, and the sound wave receiver receives the reflected infrasonic pulse shock wave and transmits the signal to the control system; S3. The control system calculates the liquid level in the oil pipe according to the signal transmitted by the sound wave receiver. The wellbore liquid level is the same as the liquid level in the oil pipe.

9. The continuous wellbore liquid level monitoring method for workover operations according to claim 8, wherein: After the step S3, it further includes the step: S4. The operator takes out the tubing from the wellbore and stacks it. During this process, the steps S1 to S3 are repeated until all the tests are completed.

10. A workover assembly, characterized in that: It includes a wellbore liquid level continuous monitoring device for workover operations as described in any one of claims 1 - 7.

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