Plunger running state and parameter obtaining method for shale gas well drainage gas recovery

Abstract

The invention discloses a plunger running state and parameter obtaining method for shale gas well drainage gas recovery. The method comprises the steps that a coupling signal generated when a plunger passes through an oil pipe is obtained; according to the matching relation between the coupling signal and a time shaft, plunger operation state parameters are obtained; the operation state parameters comprise the plunger operation position, the operation speed change, the liquid level position in the oil pipe and the liquid column height. Through matching of the dynamic coupling signal and the time axis, the plunger operation state parameters such as the plunger operation position, the operation speed, the liquid level position in the oil pipe and the liquid column height are obtained, the obtaining process is simple, the result is accurate and reliable, development does not need to depend on field experience, the accuracy of the plunger operation dynamic monitoring parameters is improved, and the working efficiency is improved. Reliable basis is provided for plunger type optimization, the implementation efficiency of the plunger drainage and mining process is greatly improved, and the problem that due to the lack of effective plunger operation state parameters and evaluation methods, process designers only carry out well opening and closing system design through field experience is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field gas production, and in particular to a method for obtaining the operating state and parameters of a plunger used for water drainage and gas production in a shale gas well. Background Art

[0002] The plunger process has become the main process for drainage and gas production in water-bearing gas reservoirs and shale gas due to its high degree of automation and the advantages of economy, efficiency and environmental protection. The number of wells using it is increasing.

[0003] As one of the commonly used drainage and gas production technologies in shale gas wells, the plunger process has the advantages of low cost and green environmental protection. The plunger can use the energy of the gas well to reciprocate in the oil pipe, resulting in its opening and closing well working system having a great impact on the drainage efficiency.

[0004] At present, due to the large number of relevant production parameters and the imperfection of the prediction model, there are situations where the well opening time is short and the plunger starts to rise before entering the liquid column, resulting in invalid lifting; there are situations where the well opening time is long, which may lead to a long production cycle, and the bottom hole pressure is not restored in time, which directly leads to reduced production efficiency or inability to produce. Therefore, if the operator can accurately understand the parameters such as the plunger's falling speed, arrival position, liquid accumulation height in the tubing and liquid level position, it can effectively optimize the plunger opening and closing system and provide a reliable basis for the selection of plunger types.

[0005] The existing technical solution is mainly to collect relevant data for analysis and calculation after the plunger runs multiple times, so as to adjust the well opening and closing system. However, this method has problems such as incomplete data, inaccurate parameters, excessive human influence factors, and untimely optimization.

[0006] In view of this, this patent application is filed. Summary of the invention

[0007] Due to the lack of effective plunger operating status parameters, process designers are unable to accurately determine parameters such as the plunger's arrival position, operating speed, liquid level position in the tubing, and liquid column height. They can only optimize the well opening and closing system based on field experience.

[0008] Therefore, the purpose of the present invention is to provide a method for obtaining the operating status and parameters of the plunger, so as to solve the problem that due to the lack of effective plunger operating status parameters and evaluation methods, process designers can only design the well-opening and closing system through field experience. The existing technical solutions mainly collect relevant data for analysis and calculation after the plunger has run multiple times, so as to adjust the well-opening and closing system, but there are problems such as incomplete data, inaccurate parameters, excessive human influence factors, and untimely optimization. Therefore, the present invention provides a method for obtaining the operating status and parameters of the plunger, which can analyze data including the operating position of the plunger, the trend of operating speed changes, the position of liquid accumulation in the oil pipe, the height of the liquid column, etc., improves the accuracy of the dynamic monitoring parameters of the plunger operation, provides a reliable basis for the timely optimization of the plunger well-opening and closing system and the optimization of the plunger tool type, and greatly improves the implementation efficiency of the plunger drainage process.

[0009] The present invention provides a method for obtaining the plunger operation status and parameters for drainage and gas production in shale gas wells, which adopts the following technical solutions:

[0010] S1: Get the coupling signal when the plunger passes through the oil pipe;

[0011] S2: Obtaining plunger operation status parameters according to the matching relationship between the coupling signal and the time axis;

[0012] The operating state parameters include the operating position of the plunger, the change in operating speed, the position of the liquid level in the oil pipe, and the height of the liquid column.

[0013] The embodiment of the present invention obtains the dynamic coupling signal when the plunger passes through the oil pipe, and then combines the dynamic coupling signal with time, so as to analyze data including the plunger running position, running speed change trend, liquid accumulation position in the oil pipe, liquid column height, etc., thereby improving the accuracy of the dynamic monitoring parameters of the plunger operation, providing a reliable basis for the timely optimization of the plunger switching well system and the optimization of the plunger tool type, and greatly improving the implementation efficiency of the plunger production process.

[0014] In an optional embodiment, the method for obtaining the coupling signal when the plunger passes through the oil pipe is: integrating an eddy current sensor in the plunger tool, and the signal change generated by the eddy current sensor when passing through the torque buckle gap of the API standard oil pipe thickening buckle is the coupling signal.

[0015] In the embodiment of the present invention, an eddy current sensor is integrated on the plunger to obtain the coupling signal of the plunger passing through the oil pipe. By matching the coupling signal with the time axis, the plunger operation state parameters such as the plunger operation position, operation speed change, liquid level position in the oil pipe, and liquid column height are obtained. This solves the problem that due to the lack of effective plunger operation state parameters and evaluation methods, process designers can only design the opening and closing well system based on field experience, and provides a reliable basis for the optimization of plunger types.

[0016] In an optional embodiment, the coupling signal is compared with the pipe string parameters of the API standard tubing thickening buckle, and the position parameters of the plunger running in the tubing are obtained in combination with the time axis.

[0017] In an optional embodiment, the plunger with an eddy current sensor continuously passes through the coupling during its operation in the oil pipe to generate a coupling signal, reads the number N of collected coupling signals and compares them with the pipe string parameters of the lowered oil pipe, obtains the specific position of the N+1th oil pipe, and completes the acquisition of the plunger operation position parameters.

[0018] In an optional embodiment, the liquid level position and the height of the liquid column in the oil pipe are obtained based on the difference between the plunger coupling signal and the time axis.

[0019] In an optional embodiment, the difference between the plunger coupling signal and the time axis is obtained by the length of the interval between the coupling signals of the two oil pipes before and after the plunger enters the liquid surface.

[0020] In the embodiment of the present invention, the method for obtaining the liquid level position and the liquid column height is converted into the interval time between the appearance of the coupling signals of the two oil pipes before and after the plunger enters the liquid surface. The acquisition process is simple, the coupling signal value acquisition process is convenient, and the result is accurate, so that the structure of the liquid level position and the liquid column height is accurate and reliable.

[0021] In an optional embodiment, the depth of the liquid level in the oil pipe is H y =S×n.

[0022] Among them, S represents the length of each oil pipe, and n represents the nth oil pipe.

[0023] In an optional embodiment, the height H of the liquid column in the oil pipe m =H k -H y ;

[0024] Among them, H k Represents the lower depth of the plunger check valve retainer.

[0025] In an optional embodiment, the running speed of the plunger during the rising and falling process is obtained based on the time difference of the coupling signal generated when the plunger passes between the couplings, so as to obtain the speed change trend.

[0026] In an optional embodiment, the running speed is V1=S / t1-t0;

[0027] Wherein, V1 represents the speed of the plunger running in the first oil pipe, S represents the length of each oil pipe, t1 represents the time when the plunger passes through the first coupling, and t0 represents the initial time when the plunger starts running;

[0028] The speed variation trend is obtained according to the running speed of the plunger in each oil pipe.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] (1) The method for obtaining the plunger operation status and parameters provided in the embodiment of the present invention can obtain the coupling signal of the plunger passing through the oil pipe by integrating an eddy current sensor on the plunger. By matching the coupling signal with the time axis, the plunger operation status parameters such as the plunger operation position, operation speed, liquid level position in the oil pipe, and liquid column height are obtained. The acquisition process is simple, the results are accurate and reliable, and there is no need to rely on field experience. It provides a reliable basis for the optimization of plunger types and solves the problem that process designers can only design the opening and closing well system based on field experience due to the lack of effective plunger operation status parameters and evaluation methods.

[0031] (2) The plunger operation status and parameter acquisition method provided in the embodiment of the present invention converts the method of acquiring the liquid level position and the liquid column height into the interval time between the appearance of the coupling signals of the two oil pipes before and after the plunger enters the liquid surface. The acquisition process is simple, the coupling signal value acquisition process is convenient, and the result is accurate, so that the structure of the liquid level position and the liquid column height is accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0033] Figure 1 A flow chart of a method for obtaining the operating status and parameters of a plunger provided in an embodiment of the present invention.

[0034] Figure 2 A structural diagram of a plunger operation position monitoring device provided in an embodiment of the present invention.

[0035] Marks and corresponding parts names in the attached drawings:

[0036] 1-fishing head, 2-controller, 3-non-metallic mounting sleeve sealing component, 4-non-metallic mounting sleeve, 5-eddy current sensor, 6-sensor mounting seat, 7-end face cover, 8-end face eddy current sensor, 9-end cover sealing component. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0039] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0040] In the description of the embodiments of the present application, the terms "center", "up", "down", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inside", "outside", "front", "back", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the products of the application are conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. They are merely for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0041] In the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "opened", "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] Embodiment 1:

[0043] like Figure 1 As shown in , this embodiment provides a method for obtaining the operating status and parameters of the plunger, and the parameters targeted include: the operating position of the plunger, the trend of the operating speed change, the liquid level position in the oil pipe, and the height of the liquid column.

[0044] Among them, for the running position of the plunger, the eddy current sensor is integrated in the plunger to capture the signal of the oil pipe coupling. The principle of eddy current detection is that a metal conductive object will generate an eddy current signal in the process of cutting the magnetic flux lines, and the signal can be captured. However, after the commonly used API standard oil pipe thickening buckle is connected, there will be a certain gap at the coupling. In this embodiment, an eddy current sensor is integrated in the plunger to form a plunger running position monitoring device. When the eddy current sensor passes through the gap, it will stimulate the eddy current effect, thereby generating a captureable coupling signal.

[0045] Specifically, the structure of the plunger operation position monitoring device formed by integrating the eddy current sensor in the plunger is as follows: Figure 2 As shown in , the device can be used as a plunger tool and can locate underground and record its own operating status data. The plunger operating position monitoring device includes a fishing head 1, a controller 2, and a position monitoring module.

[0046] The fishing head 1 is located at the top of the plunger running position monitoring device and is used for fishing and recovering the collection device.

[0047] The controller 2 includes a circuit board, a power module, a data storage module, and a real-time clock module, which are used to control the communication between the modules, monitor the operating status of the acquisition device, monitor the data of the position detection module and the end face detection module, and the real-time time of the system.

[0048] The position monitoring module is composed of an eddy current sensor 5, a non-metallic mounting sleeve 4, a sensor mounting seat 6 and a non-metallic mounting sleeve sealing component 3, wherein the eddy current sensor 5 is used to sense metal substances. Since the real-time tracking and monitoring device for the operation status of the plunger will collide with the oil pipe during the falling process, the sensing surface of the eddy current sensor 5 cannot always remain directly opposite the coupling. In order to avoid false triggering of signals and missed coupling signals, a total of four groups of eddy current sensors 5 are provided and are all connected to the controller 2. The four groups of eddy current sensors 5 are at an angle of 90° to each other and are installed in the sensor mounting seat 6. The sensor mounting seat 6 is evenly arranged on the inner wall of the plunger operation position monitoring device. The non-metallic mounting sleeve 4 is arranged on the outside of the sensor mounting seat 6, is made of peek pressure-bearing material, and is sealed by the non-metallic mounting sleeve sealing component 3.

[0049] The plunger running position monitoring device monitors the changes in the metal inner wall of the oil pipe in real time through the output signal of the position detection module, and then analyzes the number of couplings passed by the plunger-type acquisition device, which is used for subsequent comparison with the oil pipe string data to obtain the plunger running position.

[0050] The end face detection module is provided with an end face eddy current sensor 8 , an end face cover 7 and an end cover sealing component 9 . The end face eddy current sensor 8 is connected to the controller 2 . The end face cover 7 is made of peek pressure-bearing material and is sealed by the end cover sealing component 9 .

[0051] The real-time tracking and monitoring device for the operation status of the plunger senses the metal material at the front end of the real-time tracking and monitoring device for the operation status of the plunger through the output signal of the end face detection module, and then determines whether the plunger-type collection device has reached the position of the retainer.

[0052] In the process of this embodiment, the plunger with the eddy current sensor continuously passes through the coupling during the operation in the oil pipe, thereby generating a coupling signal. The number N of collected coupling signals is read by the computer end, and by comparing with the pipe string parameters of the lowered oil pipe, the specific position of the N+1th oil pipe is found, so as to determine that the plunger has fallen to this position, that is, the acquisition of the plunger operation position parameters is completed.

[0053] The running speed trend of the plunger is determined by the relationship between the obtained tubing coupling signal and the time axis. The running speed of the plunger during the rising and falling process is obtained based on the time difference of the coupling signal generated when the plunger passes between the couplings to obtain the speed change trend.

[0054] Specifically, the initial time when the plunger starts to run is t0, the time it passes through the first coupling is t1, the first coupling signal obtained is N1, and so on. During the operation of the plunger, assuming that the length S of each oil pipe is the same, the speed of the plunger running in the first oil pipe can be calculated by the time difference t1-t0 between the two coupling signals N1 and N2, that is, V1=S / t1-t0. The running speed of the plunger in each oil pipe can be obtained through this calculation. According to the running speed of the plunger in each oil pipe, the speed change law can be obtained, providing a more accurate basis for the parameters required for the optimization of the plunger system.

[0055] The liquid level position parameters and liquid column height in the tubing are obtained based on the difference between the plunger coupling signal and the time axis, and the difference between the plunger coupling signal and the time axis is obtained by the interval time between the coupling signals of the two tubings before and after the plunger enters the liquid surface.

[0056] Specifically:

[0057] The acquisition of the position parameters of the liquid level in the oil pipe is mainly determined by the speed of the plunger. Assuming that the position of the liquid level in the oil pipe is at the nth oil pipe, the speed V at which the plunger runs to this position n , and because there is a big difference between the speed of the plunger in the air and the speed of the plunger in the liquid, the speed V of the plunger when it runs to the n+1 oil pipe is n+1 Will be better than V n The depth of the liquid surface in the oil pipe can be obtained by combining the actual oil pipe parameters. y =S×n. S represents the length of each oil pipe, and n represents the nth oil pipe.

[0058] The height parameter Hm of the liquid column in the oil pipe can be obtained by knowing the depth H of the plunger check valve retainer. k The above calculated depth H of the liquid level in the oil pipe y Calculated: H m =H k -H y .

[0059] Due to the existing technical conditions, there is no effective means to analyze the specific falling position, falling speed, liquid column height and other important parameters of the plunger under different working conditions. The basis of current production management is mainly to predict the time when the plunger enters the liquid surface and reaches the bottom of the well through theoretical models, so as to control the opening and closing time of the switch valve to implement production for the gas well. However, due to the large number of relevant production parameters and the imperfection of the prediction model, the actual value will deviate greatly from the predicted value. If the valve opening time is too fast, the plunger will start to rise before entering the liquid column, resulting in the plunger doing useless work. If the valve opening time is too long, too much liquid may accumulate and cause the plunger to fail to lift. At the same time, abnormal situations such as the plunger being stuck in the tubing string may occur. If the operator can accurately understand the plunger's falling speed, position, and the time required for the plunger to fall to the liquid surface and the bottom of the tubing string, then the opening, closing and maintenance time can be effectively arranged to improve work efficiency.

[0060] A method for obtaining plunger operation status parameters provided by an embodiment of the present invention can obtain the coupling signal of the plunger passing through the oil pipe by integrating an eddy current sensor on the plunger. By matching the coupling signal with the time axis, the operating position of the plunger in the oil pipe, the operating speed trend, the liquid level position in the oil pipe, and the liquid column height and other parameters can be effectively obtained, thereby improving the accuracy of the plunger operation status monitoring parameters, which is conducive to accurately guiding the optimization timing of the plunger switching well system, and providing a reliable basis for the optimization of the plunger switching well system and the optimization of the plunger tool type, thereby improving the plunger gas lift efficiency, improving the process production increase effect, and greatly improving the implementation efficiency of the plunger drainage process. At the same time, the plunger operation status and parameter acquisition method provided by the embodiment of the present invention converts the acquisition method of the liquid level position and the liquid column height into the interval time between the coupling signals of the two oil pipes before and after the plunger enters the liquid surface. The acquisition process is simple, the coupling signal value acquisition process is convenient, and the result is accurate, so that the structure of the liquid level position and the liquid column height is accurate and reliable.

[0061] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for obtaining the plunger operation status and parameters for shale gas well drainage and gas production, characterized in that: include: S1: Get the coupling signal when the plunger passes through the oil pipe; S2: Obtaining plunger operation status parameters according to the matching relationship between the coupling signal and the time axis; The operating state parameters include the operating position of the plunger, the change in operating speed, the position of the liquid level in the oil pipe, and the height of the liquid column.

2. According to claim 1, a plunger operation status and parameter acquisition method for shale gas well drainage and gas production involves a plunger operation position monitoring device, which is composed of a fishing head, a controller, and a position monitoring module. The number of tubing couplings is collected by the signal changes generated when passing through the API standard tubing thickening buckle gap.

3. The controller according to claim 2 is mainly composed of a circuit board, a power module, a data storage module and a real-time clock module, and the circuit board is arranged in the plunger operation position monitoring device and connected to the eddy current sensor.

4. According to the position monitoring module described in claim 2, it is mainly composed of an eddy current sensor, a non-metallic mounting sleeve, a sensor mounting seat and a non-metallic mounting sleeve sealing component, wherein the eddy current sensor is connected to the controller and installed in the sensor mounting seat, and the non-metallic mounting sleeve is arranged outside the sensor mounting seat, is made of peek pressure-bearing material, and is sealed by the non-metallic mounting sleeve sealing component.

5. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 2, characterized in that: The number of couplings is compared with the pipe string parameters of the API standard tubing thickening buckle, and the position parameters of the plunger running in the tubing are obtained in combination with the time axis.

6. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 3, characterized in that: The plunger with an eddy current sensor continuously passes through the coupling during its operation in the oil pipe, generating a coupling signal. The number of collected coupling signals N is read and compared with the pipe string parameters of the lowered oil pipe to obtain the specific position of the N+1th oil pipe, thereby completing the acquisition of the plunger operation position parameters.

7. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 2, characterized in that: According to the difference between the plunger coupling signal and the time axis, the liquid level position and the liquid column height in the oil pipe are obtained.

8. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 5, characterized in that: The difference between the plunger coupling signal and the time axis is obtained by the interval between the coupling signals of the two oil pipes before and after the plunger enters the liquid surface.

9. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 5, characterized in that: The depth of the liquid level in the oil pipe is H y =S×n. Among them, S represents the length of each oil pipe, and n represents the nth oil pipe.

10. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 7, characterized in that: Height of liquid column in oil pipe H m =H k -H y ; Among them, H k Represents the lower depth of the plunger check valve retainer.

11. A method for obtaining plunger operation status and parameters for drainage and gas production in shale gas wells according to claim 2, characterized in that: The running speed of the plunger during the rising and falling process is obtained according to the time difference of the coupling signal generated when the plunger passes between the couplings, so as to obtain the speed change trend.

12. A method for obtaining plunger operation status and parameters for shale gas well drainage and gas production according to claim 9, characterized in that: The running speed is V1=S / t1-t0; Wherein, V1 represents the speed of the plunger running in the first oil pipe, S represents the length of each oil pipe, t1 represents the time when the plunger passes through the first coupling, and t0 represents the initial time when the plunger starts running; The speed variation trend is obtained according to the running speed of the plunger in each oil pipe.

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