Wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system and method

Abstract

The invention relates to the technical field of return-loss and leakage oil and gas well repair of oil and gas fields, in particular to a wellbore dynamic liquid level wellhead temporary closing detection and risk assessment early warning system and method, and aims to solve the problem of sound wave diffusion caused by normal opening of a wellhead in the well repair process. The liquid level echo information cannot be directly measured; and the safety problem caused by lack of an effective gas detection early warning device is solved. The invention provides a wellbore dynamic liquid level wellhead temporary closing detection and risk assessment early warning system. The wellbore dynamic liquid level wellhead temporary closing detection and risk assessment early warning system comprises a wellhead temporary closing device, a gas detection device and a wellbore dynamic liquid level and pressure detection device. The wellhead temporary closing device is installed at a wellhead to close the wellhead, the gas detection device is used for monitoring and analyzing harmful gas, and the shaft dynamic liquid level and pressure detection device is used for monitoring the dynamic liquid level and wellhead pressure. The wellhead temporary closing device closes the wellhead to prevent sound waves from overflowing, so that effective gas detection is carried out, liquid level echo information is directly measured, and early warning is carried out in time to guarantee operation safety.

Description

Technical Field

[0001] The present invention relates to the technical field of workover for lost circulation oil and gas wells in oil and gas fields, and particularly to a wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system and method. Background Technique

[0002] Pulling and running tubing and drill pipes is a conventional workover operation. Since the liquid level and wellbore liquid column pressure will change during the operation process, unexpected situations may occur. For lost circulation oil and gas wells, if running the pipe string causes the liquid level to rise and the bottom hole pressure to be higher than the formation pressure, well leakage may occur; if during the operation of pulling out the pipe string, in an oil area with complex formation conditions and when the kill fluid leaks, the liquid level will decrease and the bottom hole pressure will be lower than the formation pressure. If the workover fluid is not replenished in a timely and accurate manner, well kick and blowout will occur, and combustible gases and toxic and harmful gases will also overflow from the wellhead, bringing risks to personnel and equipment. Therefore, taking effective measures to detect the depth of the wellbore liquid level and effectively monitor and evaluate and early warn the wellhead pressure as well as combustible gases and toxic and harmful gases is an extremely important link to ensure the safety of oil and gas well workover operations.

[0003] Existing wellbore liquid level detection devices mostly use the echo method for detection. However, during workover, since the tubing and drill pipes need to be continuously pulled up and lowered, the blowout preventer needs to be opened, resulting in the non-closure of the wellbore top. The wellhead and the upper interfaces of the pipe string are in an open state all the time. Therefore, the sound waves emitted by the liquid level detection device are scattered at the wellhead, and the liquid level echo information cannot be directly measured. In addition, during the current construction, because the wellhead and the upper interfaces of the pipe string are in an open state all the time, it is easy for combustible gases and toxic and harmful gases in the well to overflow along with the wellhead pipe string. Since there is still a lack of supporting devices that can monitor, evaluate and early warn the wellhead pressure, combustible gases and toxic and harmful gases in real time, safety early warning cannot be made in time, which is easy to cause potential safety hazards to the wellhead operation personnel. Summary of the Invention

[0004] The purpose of the present invention is to provide a wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system and method to solve the problems of sound wave scattering caused by the open wellhead during workover, which makes it impossible to directly measure the liquid level echo information, and the safety problems caused by the lack of effective gas detection and early warning devices.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is as follows:

[0006] A wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system includes a wellhead temporary closure device, a gas detection device and a wellbore dynamic liquid level and pressure detection device; the wellhead temporary closure device is installed at the wellhead to close the wellhead, the gas detection device is used to monitor and analyze harmful gases, and the wellbore dynamic liquid level and pressure detection device is used to monitor the dynamic liquid level and the wellhead pressure.

[0007] Further, the gas detection device includes a gas guide pipe and a gas detector. One end of the gas guide pipe is connected to the wellhead, and the other end is connected to the gas detector.

[0008] Further, the gas detector includes an air extraction pump, a sensor, a built-in monitoring terminal, and an acoustic-optic alarm unit; the air extraction pump is connected to the gas guide pipe to extract the gas in the wellhead to the sensor, so as to perform gas analysis through the sensor. The built-in monitoring terminal receives the signals collected by the sensor, and when the detected gas concentration reaches the threshold, the acoustic-optic alarm unit gives an acoustic-optic alarm.

[0009] Further, the wellbore dynamic liquid level and pressure detection device includes a pressure guiding pipe, a pressure transmitter, a wellbore dynamic liquid level detection unit, and a remote monitoring terminal; one end of the pressure guiding pipe is connected to the wellhead, and the other end is connected to the pressure transmitter and the wellbore dynamic liquid level detection unit, and is used to transmit the wellhead pressure to the pressure transmitter and transmit the sound wave sent by the wellbore dynamic liquid level detection unit to the wellhead; the remote monitoring terminal is used to obtain the pressure signal and the dynamic liquid level signal for monitoring.

[0010] Further, the wellbore dynamic liquid level detection unit includes a nitrogen cylinder, and the nitrogen cylinder releases gas to emit infrasound waves, and the infrasound waves reach the dynamic liquid level through the pressure guiding pipe and are reflected.

[0011] Further, the wellhead temporary closing device includes a connecting seat and an inserting plate; the connecting seat includes a first inserting plate and a second inserting plate, and semi-circular holes are provided on both the first inserting plate and the second inserting plate, and the two semi-circular holes form a first hole; the distance between the first inserting plate and the second inserting plate is adjustable to adjust the distance between the two semi-circular holes; the inserting plate is slidably connected to the connecting seat and closes the first hole, an installation hole is provided on the second inserting plate, and a conduction hole is provided on the inserting plate.

[0012] Further, the wellhead temporary closing device further includes a transmission lead screw, and the transmission lead screw is rotationally connected to the first inserting plate and the inserting plate, and the transmission lead screw rotates to drive the inserting plate to move so that the conduction hole is aligned with the installation hole.

[0013] Further, the wellhead temporary closing device includes a connecting seat and an inserting plate; the connecting seat includes a first inserting plate and a second inserting plate, and semi-circular holes are provided on both the first inserting plate and the second inserting plate, and the two semi-circular holes form a first hole; the distance between the first inserting plate and the second inserting plate is adjustable to adjust the distance between the two semi-circular holes; the inserting plate is slidably connected to the first inserting plate and forms an intermediate through hole with the second inserting plate.

[0014] Further, the wellbore dynamic liquid level wellhead temporary closing detection and risk assessment warning system further includes a network monitoring, control and warning device, and the network monitoring, control and warning device is connected to the gas detection device and the wellbore dynamic liquid level and pressure detection device to obtain gas, pressure and dynamic liquid level information, and gives an alarm when the detected value reaches the set value.

[0015] On the other hand, the present invention proposes a method for detecting the dynamic liquid level in the wellbore and risk assessment and early warning. By using the above-mentioned wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system,

[0016] Judge the risk based on the gas, pressure, and dynamic liquid level information obtained by the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system, and take corresponding measures;

[0017] When the measured pressure is less than zero and the liquid level is continuously decreasing, the wellbore is in a leakage state. At this time, reduce the density of the kill fluid and then perform kill fluid injection;

[0018] When the measured pressure is equal to zero and the liquid level is stable, the wellhead is in a non-pressure state. At this time, maintain the kill operation and continuously observe the data changes;

[0019] When the measured pressure is greater than zero and the liquid level is continuously increasing, the wellhead is in a pressurized state. At this time, increase the density of the kill fluid and then perform kill fluid injection;

[0020] Alarm when the detected gas concentration is greater than or equal to the concentration threshold.

[0021] Based on the above technical solutions, the technical effects that the present invention can achieve are as follows:

[0022] The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system provided by the present invention includes a wellhead temporary closure device, a gas detection device, and a wellbore dynamic liquid level and pressure detection device; the wellhead temporary closure device is installed at the wellhead to seal the wellhead, the gas detection device is used to monitor and analyze harmful gases, and the wellbore dynamic liquid level and pressure detection device is used to monitor the dynamic liquid level and wellhead pressure.

[0023] The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system provided by the present invention seals the wellhead through the wellhead temporary closure device to prevent the dispersion of sound waves, so that the gas detection device and the wellbore dynamic liquid level and pressure detection device can effectively detect gases and directly measure the liquid level echo information, and then timely early warning can be carried out to ensure the safety of operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1Schematic diagram of the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system provided by the embodiments of the present invention;

[0026] Figure 2 Cross-sectional view of the wellhead temporary closure device for full wellhead closure;

[0027] Figure 3 Top view of the wellhead temporary closure device for full wellhead closure;

[0028] Figure 4 Cross-sectional view of the wellhead temporary closure device for casing-tubing annulus closure;

[0029] Figure 5 Cross-sectional view of the wellhead temporary closure device for casing-tubing annulus closure;

[0030] Figure 6 Schematic diagram of the female joint structure;

[0031] Figure 7 Schematic diagram of the gas detection device structure;

[0032] Figure 8 Schematic diagram of the wellbore dynamic liquid level and pressure detection device structure.

[0033] Icons: 100 - Wellhead temporary closure device; 200 - Gas detection device; 300 - Wellbore dynamic liquid level and pressure detection device; 110 - Connecting seat; 120 - Insertion plate; 130 - Transmission lead screw; 140 - Chuck gripper; 150 - Lead screw handle; 160 - Fastening screw; 170 - First chuck seal; 180 - Second chuck seal; 190 - Female joint; 111 - First plug-in board; 112 - Second plug-in board; 113 - First seal; 114 - Second seal; 191 - Joint body; 192 - First sealing ring; 210 - Gas guide pipe; 220 - Gas detector; 230 - Male joint; 310 - Pressure guiding pipe; 320 - Pressure transmitter; 330 - Wellbore dynamic liquid level detection unit; 340 - Remote monitoring terminal; 350 - Pressure signal transmission cable; 360 - Dynamic liquid level signal transmission cable; 370 - Valve; 101 - First hole; 102 - Conduction hole; 103 - Intermediate through hole. Detailed implementation manners

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0037] During the well repair process, there are problems such as the sound wave dispersion caused by the wellhead being open, the inability to directly measure the liquid surface echo information, and the safety issues caused by the lack of effective gas detection and early warning devices.

[0038] In view of this, the present invention provides a wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system, including a wellhead temporary closure device 100, a gas detection device 200 and a wellbore dynamic liquid level and pressure detection device 300; the wellhead temporary closure device 100 is installed at the wellhead to seal the wellhead, the gas detection device 200 is used to monitor and analyze harmful gases, and the wellbore dynamic liquid level and pressure detection device 300 is used to monitor the dynamic liquid level and wellhead pressure.

[0039] The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system provided by the present invention closes the wellhead through the wellhead temporary closure device 100 to prevent the spread of sound waves, so that the gas detection device 200 and the wellbore dynamic liquid level and pressure detection device 300 can effectively detect gas and directly measure the liquid level echo information, thereby providing timely early warning to ensure operation safety.

[0040] The following combination Figures 1-8 The structure and shape of the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system provided in this embodiment are described in detail:

[0041] In this embodiment, the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system includes a wellhead temporary closure device 100, a gas detection device 200, a wellbore dynamic liquid level and pressure detection device 300 and a network monitoring control early warning device.

[0042] In this embodiment, for two use conditions, namely, full wellhead closure and casing annulus closure, different structures of wellhead temporary closure devices 100 can be selected. Specifically, when the wellhead is fully closed, that is, when used for the wellhead or wellhead pipe string, the wellhead temporary closure device 100 includes a connecting seat 110, an insert plate 120, a transmission screw 130, a chuck gripper 140, a screw handle 150, a tightening screw 160 and a female connector 190. Figure 2 , Figure 3As shown, the connecting seat 110 includes a first plug-in board 111 and a second plug-in board 112, which are spliced with each other and have an L-shaped cross-section. The plug-in disc 120 is arranged on the first plug-in board 111 and spliced with the second plug-in board 112. That is, the three cooperate together to form a sealing surface and a first hole 101 is formed below the sealing surface. The first hole 101 cooperates with the wellhead to be sleeved on the wellhead. Among them, semi-circular holes are provided on both the first plug-in board 111 and the second plug-in board 112, and the two semi-circular holes form the first hole 101. The fastening screw 160 is inserted into the first plug-in board 111 and the second plug-in board 112 and fastened with nuts at both ends so that the first plug-in board 111 and the second plug-in board 112 form an integral body and are firmly clamped on the wellhead to achieve reliable sealing of the wellhead. Through the connection method of the fastening screw 160, the distance between the first plug-in board 111 and the second plug-in board 112 is adjustable, so as to match wellheads of different specifications and lock the first hole 101 with the wellhead. At the same time, the installation with the wellhead is carried out in an inserted manner, which is convenient for installation and easy to install and fasten.

[0043] One end of the transmission lead screw 130 is connected to the lead screw handle 150, and the other end is rotatably connected to the plug-in disc 120. Specifically, a boss is provided at one end of the transmission lead screw 130 inserted into the plug-in disc 120, and the boss is clamped in the groove on the plug-in disc 120 and rotatably connected thereto. At the same time, the transmission lead screw 130 is rotatably connected to the first plug-in board 111, and corresponding threads are provided on the first plug-in board 111 corresponding to the transmission lead screw 130 to achieve transmission connection. When the transmission lead screw 130 is rotated, the plug-in disc 120 can be driven to move along the axis of the transmission lead screw 130. As Figure 2 、 Figure 3 shown, an installation hole is provided on the second plug-in board 112 for installing the female joint 190. Due to structural limitations, the positions of one of the female joints 190 overlap with those of the plug-in disc 120. To ensure that the female joint 190 can communicate with the wellhead, a conduction hole 102 is provided on the plug-in disc 120. When the distance between the first plug-in board 111 and the second plug-in board 112 is adjusted, the female joint 190 and the conduction hole 102 are misaligned. At this time, rotating the transmission lead screw 130 can align the conduction hole 102 with the female joint 190 to ensure the communication state. Among them, the female joint 190 is used to connect with the gas detection device 200 and the wellbore dynamic liquid level and pressure detection device 300.

[0044] In this embodiment, the chuck gripper 140 is connected to the second plug-in board 112, which is used to facilitate the handling and lifting of the connecting seat 110 or the second plug-in board 112.

[0045] When the tubing-casing annulus is sealed, that is, when it is used for the wellhead tubing or drill pipe, a first chuck seal 170 and a second chuck seal 180 are added on the basis of the above wellhead temporary closing device 100, and corresponding adjustments are made to the first plug-in board 111, the second plug-in board 112 and the plug-in disc 120, as Figure 4 、 Figure 5As shown. Specifically, the first plug-in board 111 and the second plug-in board 112 are changed to a butt joint form, and the first chuck seal 170 and the second chuck seal 180 are respectively installed on one side where the first plug-in board 111 and the second plug-in board 112 are butted, and the first chuck seal 170 and the second chuck seal 180 form a reliable seal.

[0046] Meanwhile, the plug plate 120 is located above the first plug-in board 111 and butts with the second plug-in board 112. The plug plate 120 and the second plug-in board 112 are both provided with semi-circular holes to form an intermediate through hole 103, and the intermediate through hole 103 is used for the passage of oil pipes, drill pipes, etc. To ensure the sealing performance, the connecting seat 110 further includes a first seal 113 and a second seal 114. The first seal 113 and the second seal 114 are respectively installed on the inner walls of the semi-circular holes where the plug plate 120 and the second plug-in board 112 are butted to form a reliable seal with the oil pipe, drill pipe, etc. At this time, the two female connectors 190 are respectively located on the plug plate 120 and the second plug-in board 112.

[0047] In this embodiment, each structural member of the wellhead temporary closure device 100 is made of 3Cr17Ni7Mo2N austenitic stainless steel anti-sulfur material. The first chuck seal 170, the second chuck seal 180, the first seal 113 and the second seal 114 are all made of rubber material and are connected to the base member in a vulcanized manner. Among them, the first chuck seal 170 and the second chuck seal 180 are of plate-like structure, and the first seal 113 and the second seal 114 are of semi-circular ring structure.

[0048] In this embodiment, the female connector 190 includes a connector body 191 and a first sealing ring 192. As Figure 6 shown, the connector body 191 is inserted into the second plug-in board 112 or the plug plate 120 by means of threaded connection, and the first sealing ring 192 is installed in the inner hole of the connector body 191 to improve the sealing performance.

[0049] In this embodiment, the metal rigid bodies are all processed and manufactured with 3Cr17Ni7Mo2N austenitic stainless steel anti-sulfur material, and the rubber sealing materials are all processed and manufactured with hydrogenated nitrile rubber that can simultaneously resist H2S, oil, acids and alkalis.

[0050] In this embodiment, the gas detection device 200 includes a gas guide pipe 210, a gas detector 220 and a male connector 230. One end of the gas guide pipe 210 is connected to the male connector 230, and the other end is communicated with the gas detector 220. The male connector 230 is inserted into the female connector 190 to connect the gas guide pipe 210 to the wellhead. As Figure 7As shown in the figure. There are two second sealing rings arranged on the outer side of the body 191 of the male connector 230. The two second sealing rings are integrally formed with the body of the male connector 230 by vulcanization process, and the interval width between the two second sealing rings is smaller than the width of the first sealing ring 192 on the female connector 190. Thus, good plugging and sealing are formed through the extrusion between the three sealing rings, which has the advantages of good sealing performance, quick plugging and connection.

[0051] In this embodiment, the gas detector 220 includes an air extraction pump, a sensor, a built-in monitoring terminal and an acoustic-optic alarm unit. The air extraction pump is connected to the air guide pipe 210 to extract the gas in the wellhead to the sensor, so as to perform gas analysis through the sensor. The built-in monitoring terminal receives the signals collected by the sensor, and when the detected gas concentration reaches the threshold, the acoustic-optic alarm unit gives an acoustic-optic alarm. Among them, the sensor analyzes carbon monoxide, sulfur dioxide, hydrogen sulfide and combustible gases.

[0052] In this embodiment, the wellbore dynamic liquid level and pressure detection device 300 includes a pressure guiding pipe 310, a pressure transmitter 320, a wellbore dynamic liquid level detection unit 330, a remote monitoring terminal 340, a pressure signal transmission cable 350, a dynamic liquid level signal transmission cable 360, a valve 370 and a male connector 230, as Figure 8 shown. One end of the pressure guiding pipe 310 is connected to the male connector 230, and the male connector 230 is inserted into the female connector 190 to connect the pressure guiding pipe 310 with the wellhead; the other end of the pressure guiding pipe 310 is connected to the pressure transmitter 320 and the wellbore dynamic liquid level detection unit 330, and is used to transmit the wellhead pressure to the pressure transmitter 320 and transmit the sound wave sent by the wellbore dynamic liquid level detection unit 330 to the wellhead; the remote monitoring terminal 340 is used to obtain the pressure signal and the dynamic liquid level signal for monitoring. The two ends of the pressure signal transmission cable 350 are respectively connected to the pressure transmitter 320 and the remote monitoring terminal 340, and the two ends of the dynamic liquid level signal transmission cable 360 are respectively connected to the wellbore dynamic liquid level detection unit 330 and the remote monitoring terminal 340, so as to realize signal transmission. The valve 370 is installed on the pressure guiding pipe 310 and is arranged between the pressure transmitter 320 and the wellbore dynamic liquid level detection unit 330 to control the transmission of the infrasonic wave signal.

[0053] Among them, the wellbore dynamic liquid level detection unit 330 includes a nitrogen cylinder. The nitrogen cylinder releases gas to emit infrasonic waves, and the infrasonic waves reach the dynamic liquid level through the pressure guiding pipe 310 and are reflected. Specifically, the nitrogen cylinder stores high-pressure gas. When releasing, the valve 370 is opened, and the infrasonic waves are transmitted to the dynamic liquid level through the pressure guiding pipe 310, and the reflected infrasonic waves return through the pressure guiding pipe 310.

[0054] In this embodiment, the network monitoring and control warning device is connected to the gas detection device 200 and the wellbore dynamic liquid level and pressure detection device 300 to obtain gas, pressure, and dynamic liquid level information, and issue an alarm when the detected value reaches the set value. Specifically, the control unit of the network monitoring and control warning device is equipped with a dedicated artificial intelligence machine learning algorithm program, which can combine the set operation program and data threshold to process the measured pressure and liquid level data in real time and turn them into corresponding picture materials. After professional training, it can independently judge the corresponding picture materials, so as to conduct real-time risk assessment and warning: when the artificial intelligence machine learning algorithm program concludes through judgment that "the measured pressure is less than zero and the liquid level in the pipe string is in a continuous decreasing state", it indicates that there is a backflow phenomenon at the wellhead and the wellbore is in a negative pressure state. At this time, the liquid column pressure in the wellbore is greater than the formation pressure, and the wellbore is in a leakage state. At this time, the on-site operator should be prompted to reduce the density of the kill fluid and then perform kill fluid injection; when the artificial intelligence machine learning algorithm program concludes through judgment that "the measured pressure is equal to zero and the liquid level in the pipe string is in a stable state", it indicates that the wellhead is in a pressureless state. At this time, the liquid column pressure in the wellbore is greater than the formation pressure, and the wellbore may be in a balanced state. At this time, it is advisable to prompt the on-site operator to pay attention to maintaining the existing kill operation state and continuously observe the changes in relevant data; when the artificial intelligence machine learning algorithm program concludes through judgment that "the measured pressure is greater than zero and the liquid level in the pipe string is in a continuous increasing state", it indicates that the wellhead is in a pressurized state. At this time, the liquid column pressure in the wellbore is less than the formation pressure, and the wellbore may be in a state of kill instability. At this time, it is advisable to prompt the on-site operator to increase the density of the kill fluid and then perform kill fluid injection. Compared with the method of manual reading and recognition, the network monitoring and control warning device has high timeliness and high accuracy, which is conducive to discovering risks and issuing warnings in the first time, and at the same time avoids the problem of difficult manual data reading.

[0055] In this embodiment, based on the 4G network technology, the control unit is connected to the built-in monitoring terminals of the remote monitoring terminal 340 and the gas detector 220. The control unit collects relevant gas, pressure, and dynamic liquid level information, and makes timely feedback to the site according to the prompt result calculated and evaluated by the control unit, and sends relevant warning signals to each monitoring terminal so that the on-site operators can implement reasonable treatment measures in the first time. When the pressure and gas content at the wellhead change to the dangerous range, the monitoring terminal performs sound and light warnings to improve the safety during the workover operation construction process.

[0056] The working process of the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment warning system provided in this embodiment is as follows:

[0057] Select a suitable wellhead temporary closure device 100 for installation according to the detection requirements, and connect the gas detection device 200, the wellbore dynamic liquid level and pressure detection device 300, and the network monitoring, control and warning device.

[0058] Taking the wellhead or wellhead string as an example, during operation, the network monitoring, control and warning device sends instructions to the gas detection device 200 to make the air pump extract the gas in the wellhead or wellhead string to the sensor at regular intervals. The sensor analyzes the gas, and the built-in control terminal receives the signals collected by the sensor and converts them into corresponding digital signals such as gas concentration and air pressure, and then sends the signals to the network monitoring, control and warning device. When the detected gas concentration is greater than or equal to the concentration threshold, the sound and light alarm unit gives corresponding sound and light alarms according to the instructions issued by the network monitoring, control and warning device.

[0059] At the same time, the pressure transmitter 320 senses the pressure in the wellhead or the inner cavity of the wellhead string through the pressure transmitted by the pressure guiding pipe 310 and transmits it to the remote monitoring terminal 340 through the pressure signal transmission cable 350. In addition, the pressure guiding pipe 310 can simultaneously transmit the infrasound waves sent by the wellbore dynamic liquid level detection unit 330 into the wellhead or the inner cavity of the wellhead string, and the reflected infrasound waves return through the pressure guiding pipe 310 so that the wellbore dynamic liquid level detection unit 330 obtains the dynamic liquid level signal. The dynamic liquid level signal is transmitted to the remote monitoring terminal 340 through the dynamic liquid level signal transmission cable 360. The remote monitoring terminal 340 transmits the pressure signal and the dynamic liquid level signal to the network monitoring, control and warning device. When the pressure in the wellhead / inner cavity of the wellhead string exceeds the safe use range of the wellbore dynamic liquid level detection unit 330, the network monitoring, control and warning device issues a risk warning, reminds the on-site construction personnel to make corresponding well control preparations, and sends relevant instructions to control the valve 370 to close to ensure the safety of the wellbore dynamic liquid level detection unit 330.

[0060] As the command center, it can conduct real-time analysis and evaluation of relevant data based on professional artificial intelligence learning methods and algorithm programs, and conduct real-time assessment and warning of relevant risks, which can effectively solve the problems of difficult manual data reading and difficult to issue warnings in the first time.

[0061] The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and warning system provided by this embodiment can effectively and conveniently seal wellheads, strings or string annuli with different diameters, creating conditions for wellbore dynamic liquid level detection, and has the advantages of compact structure and convenient disassembly and assembly. This system can not only realize the temporary closure of the wellhead during the operation of tripping in and out of the string, creating conditions for effectively detecting the dynamic liquid level and pressure in the inner cavity of the wellbore string and annulus, but also can effectively detect and monitor the combustible gas and toxic and harmful gas in the string and the inner cavity of the annulus near the wellhead in real time. Furthermore, combined with artificial intelligence methods, it can realize effective risk assessment and warning, which is beneficial to improving the risk judgment ability, so as to take corresponding measures in time to ensure the smooth progress and safety of the construction.

[0062] Based on the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system provided in this embodiment, a method for wellbore dynamic liquid level detection and risk assessment and early warning is proposed, and the steps are as follows:

[0063] Judge the risk according to the gas, pressure, and dynamic liquid level information obtained by the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and early warning system and take corresponding measures; when the measured pressure is less than zero and the liquid level is in a continuous descending state, the wellbore is in a leakage state. At this time, reduce the density of the kill fluid and then perform kill fluid injection; when the measured pressure is equal to zero and the liquid level is in a stable state, the wellhead is in a pressureless state. At this time, maintain the kill operation and continuously observe the data change; when the measured pressure is greater than zero and the liquid level is in a continuous increasing state, the wellhead is in a pressurized state. At this time, increase the density of the kill fluid and then perform kill fluid injection; when the detected gas concentration is greater than or equal to the concentration threshold, the audible and visual alarm unit gives an audible and visual alarm.

[0064] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system, characterized in that, It includes a wellhead temporary closing device (100), a gas detection device (200), and a wellbore dynamic liquid level and pressure detection device (300); The wellhead temporary closing device (100) is installed at the wellhead to seal the wellhead. The gas detection device (200) is used to monitor and analyze harmful gases. The wellbore dynamic liquid level and pressure detection device (300) is used to monitor the dynamic liquid level and wellhead pressure.

2. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 1, characterized in that, The gas detection device (200) includes a gas guide pipe (210) and a gas detector (220). One end of the gas guide pipe (210) is connected to the wellhead, and the other end is connected to the gas detector (220).

3. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 2, characterized in that, The gas detector (220) includes an air extraction pump, a sensor, a built-in monitoring terminal, and an audible and visual alarm unit; The air extraction pump is connected to the gas guide pipe (210) to extract the gas in the wellhead to the sensor, so as to perform gas analysis through the sensor. The built-in monitoring terminal receives the signals collected by the sensor, and when the detected gas concentration reaches the threshold, the audible and visual alarm unit gives an audible and visual alarm.

4. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 1, characterized in that, The wellbore dynamic liquid level and pressure detection device (300) includes a pressure guiding pipe (310), a pressure transmitter (320), a wellbore dynamic liquid level detection unit (330), and a remote monitoring terminal (340); One end of the pressure guiding pipe (310) is connected to the wellhead, and the other end is connected to the pressure transmitter (320) and the wellbore dynamic liquid level detection unit (330), and is used to transmit the wellhead pressure to the pressure transmitter (320) and transmit the sound wave sent by the wellbore dynamic liquid level detection unit (330) to the wellhead; The remote monitoring terminal (340) is used to obtain pressure signals and dynamic liquid level signals for monitoring.

5. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 4, characterized in that, The wellbore dynamic liquid level detection unit (330) includes a nitrogen cylinder. The nitrogen cylinder releases gas to emit infrasonic waves, and the infrasonic waves reach the dynamic liquid level through the pressure guiding pipe (310) and are reflected.

6. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 5, characterized in that, The wellhead temporary closing device (100) includes a connecting seat (110) and an inserting plate (120); The connecting seat (110) includes a first plugging plate (111) and a second plugging plate (112). Semi-circular holes are provided on both the first plugging plate (111) and the second plugging plate (112), and the two semi-circular holes form a first hole (101). The distance between the first plugging plate (111) and the second plugging plate (112) is adjustable to adjust the distance between the two semi-circular holes. The inserting plate (120) is slidably connected to the connecting seat (110) and closes the first hole (101). An installation hole is provided on the second plugging plate (112), and a conduction hole (102) is provided on the inserting plate (120).

7. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 6, characterized in that, The wellhead temporary closing device (100) further includes a transmission lead screw (130). The transmission lead screw (130) is rotationally connected to the first plugging plate (111) and the inserting plate (120). The transmission lead screw (130) rotates to drive the inserting plate (120) to move so that the conduction hole (102) is aligned with the installation hole.

8. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 1, characterized in that, The wellhead temporary closing device (100) includes a connecting seat (110) and an inserting plate (120); The connection base (110) includes a first plug-in board (111) and a second plug-in board (112). Semi-circular holes are provided on both the first plug-in board (111) and the second plug-in board (112), and the two semi-circular holes form a first hole (101); the distance between the first plug-in board (111) and the second plug-in board (112) is adjustable to adjust the distance between the two semi-circular holes; The plug-in disc (120) is slidably connected to the first plug-in board (111) and forms an intermediate through hole (103) with the second plug-in board (112).

9. The wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to claim 1, characterized in that, It further includes a network monitoring, control and warning device, which is connected to the gas detection device (200) and the wellbore dynamic liquid level and pressure detection device (300) to obtain gas, pressure and dynamic liquid level information, and alarms when the detected value reaches the set value.

10. A wellbore dynamic liquid level detection and risk assessment early warning method, adopting the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment early warning system according to any one of claims 1-9, characterized in that, Judge risks and take corresponding measures according to the gas, pressure, and dynamic liquid level information obtained by the wellbore dynamic liquid level wellhead temporary closure detection and risk assessment and warning system; When the measured pressure is less than zero and the liquid level is in a continuously decreasing state, the wellbore is in a leakage state. At this time, reduce the density of the kill fluid and then perform kill fluid injection. When the measured pressure is equal to zero and the liquid level is in a stable state, the wellhead is in a non-pressure state. At this time, maintain the kill operation and continuously observe the data changes. When the measured pressure is greater than zero and the liquid level is in a continuously increasing state, the wellhead is in a pressure-bearing state. At this time, increase the density of the kill fluid and then perform kill fluid injection. Alarm when the detected gas concentration is greater than or equal to the concentration threshold.

Images