A device and method for monitoring leakage of underground injection and production pipe

Abstract

The present invention provides an underground injection and production tubing leakage monitoring device and method, which relate to the field of petroleum and natural gas engineering technology. The device includes: a temperature monitoring module, which is used to monitor the temperature data of the underground injection and production tubing, wherein an annular layer is provided on the side of the underground injection and production tubing away from the injection and production channel, and annular liquid is provided in the annular layer, and the temperature data includes the temperature of the annular liquid at the leakage point of the underground injection and production tubing; a density monitoring module, which is used to monitor the density of the annular liquid; a fluid pressure monitoring module, which is used to monitor the fluid pressure of the annular liquid at the leakage point of the underground injection and production tubing; and a first data processing module, wherein the input end of the first data processing module is connected to the output end of the temperature monitoring module, the output end of the density monitoring module and the output end of the fluid pressure monitoring module, and the first data processing module is used to determine a first leakage rate of the leakage point of the underground injection and production tubing according to the temperature data, the density of the annular liquid and the fluid pressure of the annular liquid.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of oil and gas engineering technology, and in particular to an underground injection and production string leakage monitoring device and method. Background Art

[0002] Underground injection and production tubing connects the underground storage chamber to the aboveground receiving device. The tightness of the tubing is essential for the proper operation of the helium storage facility. However, during the injection and production process, the tubing is exposed to fluctuating temperatures and pressures, making it susceptible to leakage. Furthermore, the underground storage chamber is far from the surface, resulting in high monitoring costs. Even small leaks cannot be detected in a timely manner, leading to unrepaired leaks and large-scale spills, resulting in wasted resources and damage to the storage chamber.

[0003] Current underground injection and production string leakage monitoring methods have limited monitoring accuracy and are unable to detect the occurrence of trace leaks in a timely manner. They can usually only locate the leak point but cannot determine the leakage rate, thus affecting the integrity and practicality of the monitoring data. Summary of the Invention

[0004] An embodiment of the present application provides an underground injection and production string leakage monitoring device and method, which relate to the field of oil and gas engineering technology, and aim to solve the problems of current underground injection and production string leakage monitoring methods, such as limited monitoring accuracy, inability to timely monitor trace leaks, inability to determine leakage rates, and impact on the integrity and practicality of monitoring data.

[0005] In a first aspect of an embodiment of the present application, a device for monitoring leakage of an underground injection and production string is provided, comprising:

[0006] a temperature monitoring module for monitoring temperature data of an underground injection and production string, wherein an annular layer is provided on a side of the underground injection and production string away from the injection and production passage, wherein annular fluid is provided in the annular layer, and the temperature data includes the temperature of the annular fluid at a leakage point of the underground injection and production string;

[0007] A density monitoring module, used for monitoring the density of the annular fluid;

[0008] A fluid pressure monitoring module, configured to monitor the fluid pressure of the annular fluid at a leakage point of the underground injection and production string;

[0009] A first data processing module, wherein the input end of the first data processing module is connected to the output end of the temperature monitoring module, the output end of the density monitoring module and the output end of the fluid pressure monitoring module, and the first data processing module is used to determine the first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular space fluid and the fluid pressure of the annular space fluid.

[0010] In some embodiments, the underground injection and production string leakage monitoring device further includes:

[0011] The gas pressure monitoring module is used to monitor the gas pressure on the side of the annulus layer close to the surface.

[0012] In some embodiments, the underground injection and production string leakage monitoring device further includes:

[0013] A second data processing module, wherein the input end of the second data processing module is connected to the output end of the gas pressure monitoring module, and the second data processing module is used to determine the second leakage rate of the leakage point of the underground injection and production string based on the gas pressure and the well depth data of the leakage point of the underground injection and production string.

[0014] In some embodiments, the underground injection and production string leakage monitoring device further includes:

[0015] A determination module, wherein the input end of the determination module is connected to the output end of the first data processing module and the output end of the second data processing module, and the determination module is used to determine a third leakage rate of the leakage point of the underground injection and production string based on the historical leakage data of the leakage point of the underground injection and production string, the first leakage rate and the second leakage rate.

[0016] In some embodiments, the underground injection and production string leakage monitoring device further includes:

[0017] A positioning module, wherein the input end of the positioning module is connected to the output end of the temperature monitoring module, and the positioning module is used to determine the leakage point of the underground injection and production string according to the temperature data.

[0018] A second aspect of an embodiment of the present application provides a method for monitoring leakage of an underground injection and production string, comprising:

[0019] Monitor the temperature data of underground injection and production strings through the temperature monitoring module;

[0020] Monitor the density of the annular fluid through the density monitoring module;

[0021] Monitoring the fluid pressure of the annular fluid at the leakage point of the underground injection and production string by a fluid pressure monitoring module;

[0022] A first leakage rate of the leakage point of the underground injection and production string is determined by a first data processing module based on the temperature data, the density of the annular fluid and the fluid pressure of the annular fluid.

[0023] In some embodiments, the underground injection and production string leakage monitoring method further includes:

[0024] Monitoring the gas pressure of the annulus layer close to the surface through a gas pressure monitoring module;

[0025] A second leakage rate of the leakage point of the underground injection and production string is determined by a second data processing module based on the gas pressure and the well depth data of the leakage point of the underground injection and production string.

[0026] In some embodiments, the underground injection and production string leakage monitoring method further includes:

[0027] A determination module determines a third leakage rate of the leakage point of the underground injection and production string according to historical leakage data of the leakage point of the underground injection and production string, the first leakage rate, and the second leakage rate.

[0028] In some embodiments, before the step of determining the first leakage rate of the leakage point of the underground injection-production string based on the temperature data, the density of the annular fluid, and the fluid pressure of the annular fluid by the first data processing module, the method further includes:

[0029] The leakage point of the underground injection and production string is determined according to the temperature data by a positioning module.

[0030] In some embodiments, the underground injection and production string leakage monitoring method further includes:

[0031] Obtaining the gas pressure in the injection and production channel of the underground injection and production string;

[0032] The leakage state of the underground injection and production string is determined based on the gas pressure in the injection and production channel and the gas pressure on the side of the annulus layer close to the surface.

[0033] In the embodiment of the present application, the temperature of the annular fluid at the leakage point of the underground injection and production string is monitored by a temperature monitoring module, the density change of the annular fluid is monitored by a density monitoring module, and the fluid pressure of the annular fluid at the leakage point is monitored by a fluid pressure monitoring module. Due to the Joule-Thomson effect, when the injection and production string leaks and gas enters the annular layer, the gas in the injection and production string expands and cools. Based on the law of conservation of energy, the internal energy lost by the gas expansion is mechanically conserved with the internal energy gained by the expansion. Therefore, the first data processing module can determine the first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular fluid, and the fluid pressure of the annular fluid. This can facilitate the quantitative monitoring of trace leaks, improve the monitoring accuracy of underground injection and production string leakage, improve the sensitivity of the underground injection and production string leakage monitoring device, facilitate management personnel to make processing decisions based on the leakage rate, improve the accuracy and objectivity of the leakage rate, and improve the practicality of the monitoring results. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 A schematic structural diagram of an underground injection and production string leakage monitoring device provided in an embodiment of the present application;

[0036] Figure 2 A schematic diagram of an underground injection and production string leakage monitoring device provided in an embodiment of the present application;

[0037] Figure 3 A schematic flow chart of a method for monitoring underground injection and production string leakage provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] The embodiments will be described in detail below, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following embodiments do not represent all implementation methods consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application as detailed in the claims. In the several embodiments provided in the embodiments of the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways, and the device embodiments described below are merely exemplary.

[0039] In a first aspect of an embodiment of the present application, a device for monitoring leakage of an underground injection and production string is provided. Figure 1 This is a schematic structural diagram of an underground injection and production string leakage monitoring device provided in an embodiment of the present application. Figure 1 As shown, the underground injection and production tubing leakage monitoring device includes: a temperature monitoring module 101, which is used to monitor the temperature data of the underground injection and production tubing, an annulus layer is provided on the side of the underground injection and production tubing away from the injection and production channel, annulus fluid is provided in the annulus layer, and the temperature data includes the temperature of the annulus fluid at the leakage point of the underground injection and production tubing; a density monitoring module 102, which is used to monitor the density of the annulus fluid; a fluid pressure monitoring module 103, which is used to monitor the fluid pressure of the annulus fluid at the leakage point of the underground injection and production tubing; a first data processing module 104, the input end of the first data processing module 104 is connected to the output end of the temperature monitoring module 101, the output end of the density monitoring module 102 and the output end of the fluid pressure monitoring module 103, and the first data processing module 104 is used to determine the first leakage rate of the leakage point of the underground injection and production tubing according to the temperature data, the density of the annulus fluid and the fluid pressure of the annulus fluid.

[0040] For example, the temperature monitoring module 101 can be a temperature sensor installed on the outer wall of the underground injection and production string along the well depth direction, and can simultaneously monitor the annular fluid temperature at multiple locations. The density monitoring module 102 can be connected to the temperature monitoring module 101 to perform density monitoring when a leak is found. The fluid pressure monitoring module 103 can be installed at the same location as the temperature monitoring module 101 to simultaneously monitor the fluid pressure at multiple locations.

[0041] For example, according to the Joule-Thomson effect, the process of gas expansion through a porous plug or throttle valve is called adiabatic throttling expansion. The adiabatic throttling process is irreversible, so when the process is carried out in an adiabatic system, the work done by the external environment is equal to the change in the system's internal energy. The leakage environment of the underground injection and production string is an adiabatic environment. Therefore, the first data processing module 104 can determine the first leakage rate based on the law of conservation of energy and the phenomenon of conservation of the decrease in internal energy caused by the expansion and cooling of the injected and produced gas and the increase in mechanical energy due to expansion:

[0042]

[0043] Determine the first leakage rate. Where k represents the first moment, k+1 represents the second moment, and the second moment occurs later than the first moment, ρ k is the density of the annular fluid at the first moment, ρ k+1 is the density of the annular fluid at the second moment; C v,g is the specific heat capacity of the gas inside the annulus layer; is the temperature of the fluid at the leakage point at the first moment, is the temperature of the fluid at the leakage point at the second moment; Δt is the unit time increment; μ jT is the Joule-Thomson effect coefficient; p k is the annular fluid pressure at the first moment, p k+1 is the fluid pressure of the annulus fluid at the second moment; Δz is the infinitesimal expression of the leakage path length from the string to the annulus; v k is the first leakage rate at the first moment, v k+1 The first data processing module 104 can determine the first leakage rate v at the second moment by the above formula (1). k+1 .

[0044] It should be noted that the underground injection and production tubing leakage monitoring device determines the first leakage rate based on the leakage points one by one. Therefore, when there are two or more leakage points in the same underground injection and production tubing, the leakage rate of a single leakage point can be monitored through the above-mentioned underground injection and production tubing leakage monitoring device, which helps managers make decisions.

[0045] The temperature monitoring module 101 monitors the temperature of the annular fluid at the leakage point of the underground injection and production string, the density monitoring module 102 monitors the density change of the annular fluid, and the fluid pressure monitoring module 103 monitors the fluid pressure of the annular fluid at the leakage point. Due to the Joule-Thomson effect, when a leak occurs in the injection and production string, causing gas to enter the annular layer, the gas in the injection and production string expands and cools. Based on the law of conservation of energy, the internal energy lost by the gas expansion is mechanically conserved. Therefore, the first data processing module 104 can determine the first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular fluid, and the fluid pressure of the annular fluid. This can facilitate quantitative monitoring of trace leaks, improve the monitoring accuracy of underground injection and production string leaks, increase the sensitivity of the underground injection and production string leakage monitoring device, facilitate management personnel to make processing decisions based on the leakage rate, improve the accuracy and objectivity of the leakage rate, and enhance the practicality of the monitoring results.

[0046] In some feasible implementations, the underground injection and production string leakage monitoring device further includes: a gas pressure monitoring module for monitoring the gas pressure of the annulus layer on the side close to the surface.

[0047] Exemplarily, the gas pressure detection module may be disposed on the surface of the annulus layer close to the ground surface, in contact with the gas inside the annulus layer.

[0048] For example, by monitoring the gas pressure within the annulus, leakage of the underground injection and production string can be determined. For example, if the gas pressure within the annulus shows an increasing trend, it can be determined that the underground injection and production string has leaked; if the gas pressure remains unchanged, it can be determined that the underground injection and production string has not leaked; if the gas pressure shows a decreasing trend, it can be determined that the gas in the annulus has leaked.

[0049] For example, in the event of gas leakage in the annulus layer, the leakage rate of the annulus layer can be determined based on the change in gas pressure in the annulus layer, and the actual leakage rate of the underground injection and production string can be determined based on the leakage rate of the annulus layer and the first leakage rate.

[0050] By setting up a gas pressure monitoring module to monitor the gas pressure inside the annulus layer, the leakage of the annulus layer and the underground injection and production string can be judged to avoid leakage in the annulus layer and affect the accuracy of the first leakage rate, thereby improving the objectivity and accuracy of the leakage rate.

[0051] In some feasible embodiments, the underground injection and production tubing leakage monitoring device also includes: a second data processing module, the input end of the second data processing module is connected to the output end of the gas pressure monitoring module, and the second data processing module is used to determine the second leakage rate of the leakage point of the underground injection and production tubing based on the gas pressure and the well depth data of the leakage point of the underground injection and production tubing.

[0052] Exemplarily, the second data processing module may be used according to:

[0053]

[0054] Determine the second leakage rate. Where, P A is the gas pressure of the annulus layer, V is the volume of the underground annulus, M is the relative molecular mass of the annular gas; ρ is the density of the annular gas, Z is the compressibility factor of the annular gas, R is the molar gas constant, T is the temperature of the underground injection and production pipeline close to the surface, t is the time difference from the start of monitoring to the end of monitoring, v2 is the second leakage rate, and the above parameters are the data of the leakage point.

[0055] By determining the second leakage rate based on the gas pressure of the annulus layer through the second data processing module, the monitoring parameters can be increased, the accuracy and objectivity of the monitoring results can be improved, and it is convenient to combine with the first leakage rate to quantitatively monitor trace leakage, improve the monitoring accuracy of underground injection and production string leakage, improve the sensitivity of the underground injection and production string leakage monitoring device, further conduct quantitative analysis of the leakage situation of the underground injection and production string, and improve the monitoring quality.

[0056] In some feasible embodiments, the underground injection and production tubing leakage monitoring device also includes: a determination module, the input end of the determination module is connected to the output end of the first data processing module and the output end of the second data processing module, and the determination module is used to determine the third leakage rate of the leakage point of the underground injection and production tubing based on the historical leakage data, the first leakage rate and the second leakage rate of the leakage point of the underground injection and production tubing.

[0057] Exemplarily, the above historical leakage data is leakage rate data of an underground injection and production string that has exactly the same structure, shape, usage scenario, and leakage condition as the currently monitored underground injection and production string.

[0058] For example, the first leakage rate and the second leakage rate can be fused and analyzed based on a method combining residual correction and weight score matching. The first leakage rate and the second leakage rate can be fitted according to historical leakage data to obtain weight coefficients corresponding to the two respectively. According to the weight coefficients, the calculation method of the leakage rate of the underground injection and production string in the current state is determined.

[0059] Based on the historical leakage data, weighting is performed on the first leakage rate and the second leakage rate, which can improve the accuracy of the weighting and further improve the accuracy of the leakage rate.

[0060] In some feasible embodiments, the underground injection and production string leakage monitoring device further includes: a positioning module, the input end of the positioning module is connected to the output end of the temperature monitoring module, and the positioning module is used to determine the leakage point of the underground injection and production string based on temperature data.

[0061] For example, based on the temperature data, an area where the temperature shows a decreasing trend can be regarded as a leakage area, and the point with the lowest temperature in the leakage area can be regarded as a leakage point of the underground injection and production string.

[0062] Locating the leakage point based on temperature data can facilitate the determination of the first leakage rate, the second leakage rate and the third leakage rate according to the parameters at the leakage point, which can save computing power, improve monitoring efficiency, reduce monitoring difficulty, and realize quantitative and positioning analysis of underground injection and production string leakage, improve the practicality of monitoring data, and facilitate management personnel to make management decisions.

[0063] Figure 2 A schematic diagram of an underground injection and production string leakage monitoring device provided in an embodiment of the present application, comprising: an underground storage chamber 201, a casing shoe 202, a cement sheath 203, a first open casing 204, a second open casing 205, a ground surface 206, a sealing cap 207, a first valve 208, a nitrogen column 209, a pipe string 210, a clamp 211, an annulus fluid 212, a second valve 213, a first pipeline 214, a second pipeline 215, a first optical cable 216, a second optical cable 217, a distributed optical fiber temperature detector 218, a first cable 219, a second cable 220, a pipe string flowmeter 221, a pipe string pressure gauge 222, a pipe string thermometer 223, a third valve 224, an annulus pressure gauge 225, a computer 226, a leakage port 227, and a packer 228.

[0064] Below the surface 206, underground storage chamber 201 is tightly connected to the ground. A concentric secondary casing 205 is enclosed within a primary casing 204. The bottom of primary casing 204 is connected to cement sheath 203 via casing shoe 202. A concentric tubing string 210 is enclosed within secondary casing 205. The bottom of secondary casing 205 is connected to tubing string 210 via packer 228. The cement ring 203, the first open casing 204, the second open casing 205, and the top of the tubing string 210 are sealed with a sealing cap 207. The annulus between the first open casing 204 and the second open casing 205 is sealed with cement. A first valve 208 is installed at the junction of the top of the annulus between the first open casing 204 and the second open casing 205 and the sealing cap 207. The annulus between the second open casing 205 and the tubing string 210 consists of a nitrogen column 209 and annular fluid 212. A third valve 224 is installed at the junction of the top of the nitrogen column 209 and the sealing cap 207. A second valve 213 is installed at the junction of the tubing string 210 and the sealing cap 207. A first optical cable 216 and a second optical cable 217 are fixed to the left and right sides of the outer wall of the tubing string 210 via clamps 211 to monitor the real-time temperature distribution of the tubing string 210. The first and second optical cables 216 and 217 pass through the sealing cap 207 and are connected to a computer 226 via a distributed optical fiber temperature sensor 218. The optical signal is converted into an electrical signal and transmitted to the computer 226. The upper end of the second valve 213 is connected to a column flowmeter 221, a column pressure gauge 222, and a column thermometer 223 via a second pipeline 215, for detecting column flow, pressure, and temperature data. The column thermometer 223, column pressure gauge 222, and column flowmeter 221 are connected to a computer 226 via a first cable 219, transmitting column flow, pressure, and temperature data to the computer 226. The third valve 224 is connected to an annulus pressure gauge 225 via a second pipeline 215. The annulus pressure gauge 225 is connected to a computer 226 via a second cable 220, collecting and transmitting annulus pressure data to the computer 226. Computer 226 is equipped with a data analysis and processing system and a data fusion prediction system for data analysis, processing and fusion prediction; the data analysis and processing system processes the data, imports the processed data into a mathematical model for calculation, accurately locates the position of micro-leakage in the tubing string, obtains two sets of tubing string leakage rate data based on temperature field and annular pressure changes, and transmits the data to the data fusion prediction system; the data fusion prediction system analyzes the sources of errors in the two sets of data and determines the optimal prediction result of the tubing string micro-leakage amount.

[0065] A second aspect of the present application provides a method for monitoring leakage of an underground injection and production string. Figure 3 This is a schematic flow chart of a method for monitoring underground injection and production string leakage provided in an embodiment of the present application. Figure 3As shown, the underground injection and production string leakage monitoring method includes: step S110, monitoring the temperature data of the underground injection and production string through the temperature monitoring module; step S120, monitoring the density of the annular space fluid through the density monitoring module; step S130, monitoring the fluid pressure of the annular space fluid at the leakage point of the underground injection and production string through the fluid pressure monitoring module; step S140, determining the first leakage rate of the leakage point of the underground injection and production string according to the temperature data, the density of the annular space fluid and the fluid pressure of the annular space fluid through the first data processing module.

[0066] The temperature monitoring module monitors the temperature of the annular fluid at the leakage point of the underground injection and production string, the density monitoring module monitors the density change of the annular fluid, and the fluid pressure monitoring module monitors the fluid pressure of the annular fluid at the leakage point. Due to the Joule-Thomson effect, when the injection and production string leaks and gas enters the annular layer, the gas in the injection and production string expands and cools. Based on the law of conservation of energy, the internal energy lost by gas expansion is mechanically conserved with the internal energy gained by expansion. Therefore, the first data processing module can determine the first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular fluid, and the fluid pressure of the annular fluid. This can facilitate quantitative monitoring of trace leaks, improve the monitoring accuracy of underground injection and production string leakage, improve the sensitivity of the underground injection and production string leakage monitoring device, facilitate management personnel to make processing decisions based on the leakage rate, improve the accuracy and objectivity of the leakage rate, and improve the practicality of the monitoring results.

[0067] In some feasible embodiments, the underground injection and production tubing leakage monitoring method further includes: monitoring the gas pressure of the annulus layer close to the surface through a gas pressure monitoring module; and determining a second leakage rate of the leakage point of the underground injection and production tubing based on the gas pressure and the well depth data of the leakage point of the underground injection and production tubing through a second data processing module.

[0068] By setting up a gas pressure monitoring module to monitor the gas pressure within the annulus layer, leakage in the annulus layer and the underground injection and production string can be determined, and the annulus layer leakage can be avoided, which would affect the accuracy of the first leakage rate, thereby improving the objectivity and accuracy of the leakage rate. By using a second data processing module to determine the second leakage rate based on the gas pressure in the annulus layer, it is possible to increase monitoring parameters, improve the accuracy and objectivity of the monitoring results, and facilitate the quantitative monitoring of trace leaks in combination with the first leakage rate, thereby improving the monitoring accuracy of underground injection and production string leakage, increasing the sensitivity of the underground injection and production string leakage monitoring device, and further conducting quantitative analysis of underground injection and production string leakage, thereby improving the monitoring quality.

[0069] In some feasible embodiments, the underground injection and production tubing leakage monitoring method further includes: determining a third leakage rate of the leakage point of the underground injection and production tubing based on historical leakage data, the first leakage rate, and the second leakage rate of the leakage point of the underground injection and production tubing through a determination module.

[0070] Based on the historical leakage data, weighting is performed on the first leakage rate and the second leakage rate, which can improve the accuracy of the weighting and further improve the accuracy of the leakage rate.

[0071] In some feasible embodiments, before the step of determining the first leakage rate of the leakage point of the underground injection and production tubing string based on the temperature data, the density of the annular fluid and the fluid pressure of the annular fluid through the first data processing module, it also includes: determining the leakage point of the underground injection and production tubing string based on the temperature data through the positioning module.

[0072] Locating the leakage point based on temperature data can facilitate the determination of the first leakage rate, the second leakage rate and the third leakage rate according to the parameters at the leakage point, which can save computing power, improve monitoring efficiency, reduce monitoring difficulty, and realize quantitative and positioning analysis of underground injection and production string leakage, improve the practicality of monitoring data, and facilitate management personnel to make management decisions.

[0073] In some feasible implementations, the underground injection and production string leakage monitoring method further includes:

[0074] Obtain the gas pressure in the injection and production channel of the underground injection and production string; judge the leakage status of the underground injection and production string based on the gas pressure in the injection and production channel and the gas pressure on the side of the annulus layer close to the surface.

[0075] For example, when a leak is detected in an underground injection and production pipe, the gas pressure in the injection and production channel and the gas pressure on the surface side of the annulus layer can be monitored. When the two are equal, it can be considered that the gas pressure in the injection and production channel is equal to that in the annulus layer, the pressure on both sides of the leak is balanced, and no leakage will occur at the leak point.

[0076] For example, when the gas pressure in the injection channel and the annulus layer are equal, the leakage state of the underground injection and production string can be determined based on the change in the injection rate in the injection channel. For example, when the injection rate decreases, it can be assumed that the gas pressure inside the annulus layer is higher than the gas pressure inside the underground injection and production string, and the annulus layer will leak back into the underground injection and production string. The leaked material in the reverse leakage can be determined based on the well depth of the leakage point and the liquid level of the annular fluid. When the injection rate increases, it can be assumed that the gas pressure inside the annulus layer is lower than the gas pressure inside the underground injection and production string, and the gas inside the underground injection and production string will leak into the annulus layer. The leakage rate at this time can be determined based on the difference between the current injection rate and the injection rate corresponding to the moment when the gas pressure in the injection channel and the annulus layer are equal.

[0077] The leakage status of the underground injection and production string can be judged based on the gas pressure in the injection and production channel and the gas pressure on the side of the annulus layer close to the surface. During the leakage of the underground injection and production string, the leakage status can be predicted based on the changes in gas pressure on both sides of the leakage point, saving computing power. The injection and production rate can be adjusted according to the prediction results, which helps managers make management decisions.

[0078] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0079] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An underground injection and production string leakage monitoring device, characterized in that: include: a temperature monitoring module for monitoring temperature data of an underground injection and production string, wherein an annular layer is provided on a side of the underground injection and production string away from the injection and production passage, wherein annular fluid is provided in the annular layer, and the temperature data includes the temperature of the annular fluid at a leakage point of the underground injection and production string; A density monitoring module, used for monitoring the density of the annular fluid; A fluid pressure monitoring module, configured to monitor the fluid pressure of the annular fluid at a leakage point of the underground injection and production string; a first data processing module, wherein an input end of the first data processing module is connected to an output end of the temperature monitoring module, an output end of the density monitoring module, and an output end of the fluid pressure monitoring module, and the first data processing module is configured to determine a first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular space fluid, and the fluid pressure of the annular space fluid, based on the law of conservation of energy and the phenomenon that the reduction in internal energy caused by the expansion and cooling of the injection and production gas and the increase in mechanical energy of the expansion are conserved; A gas pressure monitoring module, used to monitor the gas pressure of the annulus layer close to the surface; a second data processing module, wherein an input end of the second data processing module is connected to an output end of the gas pressure monitoring module, and the second data processing module is configured to determine a second leakage rate of the leakage point of the underground injection and production string based on the gas state equation according to the gas pressure and the well depth data of the leakage point of the underground injection and production string; A determination module, wherein the input end of the determination module is connected to the output end of the first data processing module and the output end of the second data processing module, and the determination module is used to determine a third leakage rate of the leakage point of the underground injection and production string based on historical leakage data of the leakage point of the underground injection and production string, the first leakage rate, and the second leakage rate, and to weight the first leakage rate and the second leakage rate based on historical leakage.

2. The underground injection and production string leakage monitoring device according to claim 1, characterized in that: Also includes: A positioning module, wherein the input end of the positioning module is connected to the output end of the temperature monitoring module, and the positioning module is used to determine the leakage point of the underground injection and production string according to the temperature data.

3. A method for monitoring leakage of an underground injection and production string, characterized in that: The underground injection and production string leakage monitoring device according to any one of claims 1 to 2 is used to perform the underground injection and production string leakage monitoring method, which includes: Monitor the temperature data of underground injection and production strings through the temperature monitoring module; Monitor the density of the annular fluid through the density monitoring module; Monitoring the fluid pressure of the annular fluid at the leakage point of the underground injection and production string by a fluid pressure monitoring module; Determining, by a first data processing module, a first leakage rate of the leakage point of the underground injection and production string based on the temperature data, the density of the annular fluid, and the fluid pressure of the annular fluid, based on the law of conservation of energy and the phenomenon that the reduction in internal energy caused by the expansion and cooling of the injected and produced gas and the increase in mechanical energy of the expansion are conserved; Monitoring the gas pressure of the annulus layer close to the surface through a gas pressure monitoring module; determining, by a second data processing module, a second leakage rate of the leakage point of the underground injection and production string based on the gas state equation according to the gas pressure and the well depth data of the leakage point of the underground injection and production string; A determination module is used to determine a third leakage rate of the leakage point of the underground injection and production string based on historical leakage data of the leakage point of the underground injection and production string, the first leakage rate, and the second leakage rate, and to weight the first leakage rate and the second leakage rate based on historical leakage.

4. The underground injection and production string leakage monitoring method according to claim 3, characterized in that: Before the step of determining the first leakage rate of the leakage point of the underground injection-production string according to the temperature data, the density of the annular fluid and the fluid pressure of the annular fluid by the first data processing module, the method further includes: The leakage point of the underground injection and production string is determined according to the temperature data by a positioning module.

5. The underground injection and production string leakage monitoring method according to claim 3, characterized in that: Also includes: Obtaining the gas pressure in the injection and production channel of the underground injection and production string; The leakage state of the underground injection and production string is determined based on the gas pressure in the injection and production channel and the gas pressure on the side of the annulus layer close to the surface.

Images