A method for monitoring the reservoir stability of a depleted oil and gas storage reservoir

Abstract

The present invention discloses a method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir. The method includes a reservoir monitoring parameter measurement platform for the gas storage reservoir, an analysis module of the oil and gas field drilling platform server, and a reservoir stability evaluation module for the gas storage reservoir. The reservoir monitoring parameter measurement platform for the gas storage reservoir uploads a multi-modal device monitoring unit to collect and analyze data. The present invention collects relevant downhole information, calculates the Pearson correlation coefficient and analyzes the bidirectional coupling mechanical model for the collected downhole information. When the reservoir brittleness or pore fluid and its occurrence state exceed the preset reference stability coefficient, the reservoir stability of the gas storage reservoir is evaluated. When it does not exceed the preset reference stability coefficient, a bidirectional coupling mechanical model analysis is carried out on the changes of oil and gas fields with different depletion reasons, assisting oil and gas field engineers to timely discover local environmental changes and potential unstable factors caused by exploitation, providing a basis for engineers to optimize the exploitation link, improving the utilization efficiency of oil and gas field resources, and enhancing the safety of exploitation.

Description

Technical Field

[0001] The present invention relates to the field of evaluation of the reservoir stability of oil and gas storage reservoirs, and particularly to a method for monitoring the reservoir stability of depleted oil and gas storage reservoirs. Background Art

[0002] In recent years, underground gas storage reservoirs have been one of the hot topics in major oilfields and also one of the difficulties in exploration, development, and logging evaluation. Depleted oil and gas reservoir gas storage reservoirs are one of the four typical types of natural gas underground storage reservoirs in the world. When evaluating the reservoir of a gas storage reservoir, the evaluation of oil saturation is an important part. Generally, oil saturation is affected by lithological characteristics, electrical properties, and reservoir physical property characteristics. When the reservoir lithology is relatively pure, the physical properties are good, and the pore structure is relatively single, the reservoir oil saturation can be estimated through the reservoir resistivity.

[0003] At present, the stability of the reservoir of a gas storage reservoir is affected by the complex surface environment of the oil and gas field, various rock layers, and geological structures, and the downhole conditions of the oil and gas field are complex. The reliability of the comprehensive evaluation results of the reservoir stability of the gas storage reservoir obtained by a single technology is very low. However, the existing data collection in oil and gas fields is relatively single, and the comprehensive evaluation results of the reservoir stability of the gas storage reservoir in the oil and gas field cannot meet the requirements.

[0004] Moreover, the existing industry for monitoring the reservoir stability of gas storage reservoirs has just started, and in China, it is still in the stage of exploration and pilot projects. There is not much advanced experience at home and abroad for reference, and it is not fully applicable to the specific situation of the comprehensive evaluation of the reservoir stability of depleted strata in domestic oil and gas fields.

[0005] Therefore, there is an urgent need for a method for monitoring the reservoir stability of depleted oil and gas storage reservoirs to solve the above problems. Summary of the Invention

[0006] Aiming at the impact on the local environment during the process of depleted strata in oil and gas fields, the present invention proposes a method for monitoring the reservoir stability of depleted oil and gas storage reservoirs, which can timely and comprehensively obtain the environmental change data during the exploitation of new energy infrastructure in the open-air environment. Moreover, based on these environmental change data, the exploitation plan can be optimized in a timely manner to reduce environmental pollution and irreversible damage.

[0007] The present invention is achieved through the following technical solutions:

[0008] On the one hand, a method for monitoring the reservoir stability of depleted oil and gas storage reservoirs includes: using a measurement platform for reservoir monitoring parameters of a gas storage reservoir to collect data in the well survey of depleted strata in an oil and gas field, and collecting the reservoir monitoring parameter information of gas storage reservoirs in oil and gas fields with different depletion reasons, the pore fluid and its occurrence state, and the reservoir brittleness data.

[0009] Calculate the Pearson correlation coefficient between the pore fluid and its occurrence state and the preset reference stability coefficient of the pore fluid and its occurrence state, and calculate the Pearson correlation coefficient between the reservoir brittleness data and the preset reference stability coefficient of the reservoir brittleness. When the pore fluid and its occurrence state are higher than the preset reference stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness data is higher than the preset reference stability coefficient of the reservoir brittleness, conduct the stability evaluation of the gas storage reservoir. Otherwise, screen the pore pressure data and geological stress data from the gas storage reservoir monitoring parameter information, and combine the pore fluid and its occurrence state and the reservoir brittleness data to conduct a numerical two-way coupled mechanical model analysis on the permeability change trend of the geological structure of oil and gas fields with different depletion causes, and obtain and output the analysis result of the two-way coupled mechanical model.

[0010] Furthermore, the numerical two-way coupled mechanical model analysis on the permeability change trend of the geological structure of oil and gas fields with different depletion causes specifically includes:

[0011] Use the gas storage reservoir monitoring parameter information to construct a two-way coupled rock formation structure model in the underground of oil and gas fields with different depletion causes and conduct classification of the oil and gas reserve volume in the depleted formation;

[0012] In the two-way coupled rock formation structure model, set the limited interval of the geological and environmental coefficients and the geological stress concentration coefficient of the depleted formation stability;

[0013] Use the Darcy's law method to calculate the flow behavior of the pore fluid and obtain the medium type;

[0014] In the two-way coupled rock formation structure model, set the safety reference, limited interval of the formation pressure coefficient and permeability coefficient of the depleted formation comprehensive gas storage reservoir stability and the geological stress concentration coefficient of the depleted formation stability;

[0015] Use the obtained medium type as the characteristic dimension for the stability evaluation of the depleted formation gas storage reservoir, and conduct safety evaluation using the stability of the depleted formation gas storage reservoir and the reservoir brittleness to obtain the analysis result of the two-way coupled mechanical model.

[0016] Furthermore, when calculating the flow behavior of the pore fluid, the used in-situ stress model is the in-situ stress model of different dimensions under different rock formations; when conducting safety evaluation using the stability of the depleted formation gas storage reservoir and the reservoir brittleness, it includes the in-situ stress model, seepage model, and reservoir failure model.

[0017] Furthermore, the specific method for screening the pore pressure data and geological stress data from the gas storage reservoir monitoring parameter information is: use the Z-score normalization method to normalize the gas storage reservoir monitoring parameter information, and then use the principal component analysis algorithm to screen out the fluid and formation temperature from the normalized gas storage reservoir monitoring parameter information, and conduct evaluation on the fluid and formation temperature through the finite element analysis model.

[0018] Further, it also includes: using a reservoir monitoring parameter measurement platform to collect data in the wellbore of an exhausted formation in an oil and gas field, collecting chemical characteristic parameters of rocks in oil and gas fields with different depletion reasons, detecting the water content of the collected chemical characteristic parameters of the rocks to obtain a water content distribution; if the water content distribution shows that the combustion heat at different temperatures in the chemical characteristic parameters of the rocks is lower than the theoretical calorific value, then conduct a reservoir stability evaluation and estimate the remaining oil and gas content; if the combustion heat at different temperatures in the chemical characteristic parameters of the rocks is higher than the theoretical calorific value, continue the exploitation according to the progress.

[0019] On the other hand, a method for monitoring the stability of an oil and gas depleted reservoir is implemented through different modules, including a reservoir monitoring parameter measurement platform, an oil and gas field drilling platform server analysis module, and a reservoir stability evaluation module; the reservoir monitoring parameter measurement platform uploads a multi-modal device monitoring unit;

[0020] The reservoir monitoring parameter measurement platform is used to detect in the wellbore of an exhausted formation in an oil and gas field, collect reservoir monitoring parameter information, reservoir brittleness data, pore fluid and its occurrence state of oil and gas fields with different depletion reasons through the multi-modal device monitoring unit, and transmit the reservoir monitoring parameter information, reservoir brittleness data, pore fluid and its occurrence state to the oil and gas field drilling platform server analysis module;

[0021] The oil and gas field drilling platform server analysis module is used to calculate the Pearson correlation coefficient between the received pore fluid and its occurrence state and the preset reference stability coefficient of the pore fluid and its occurrence state, calculate the Pearson correlation coefficient between the received reservoir brittleness data and the preset reference stability coefficient of the reservoir brittleness. When the pore fluid and its occurrence state are higher than the preset reference stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness data is higher than the preset reference stability coefficient of the reservoir brittleness, the reservoir stability evaluation module is activated; otherwise, screen the pore pressure data and geological stress data from the reservoir monitoring parameter information and conduct a numerical two-way coupled mechanical model analysis on the permeability change trend of the geological structure of oil and gas fields with different depletion reasons in combination with the pore fluid and its occurrence state and the reservoir brittleness data, and obtain and output the two-way coupled mechanical model analysis result;

[0022] The reservoir stability evaluation module is used to evaluate the reservoir stability when the pore fluid and its occurrence state are higher than the preset reference stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness is higher than the preset reference stability coefficient of the reservoir brittleness.

[0023] Further, the multi-modal device monitoring unit includes: geophysical logging equipment, seismic exploration equipment, and downhole measurement equipment;

[0024] Geophysical logging equipment is used to collect information on reservoir monitoring parameters of gas storage reservoirs in oil and gas fields with different depletion causes and transmit it to the analysis module of the oil and gas field drilling platform server; seismic exploration equipment is used to collect reservoir brittleness data of oil and gas fields with different depletion causes and transmit it to the analysis module of the oil and gas field drilling platform server; downhole measurement equipment is used to collect geological and physical data of oil and gas fields with different depletion causes, analyze pore fluids and their occurrence states and transmit them to the analysis module of the oil and gas field drilling platform server.

[0025] Furthermore, the multi-modal equipment monitoring unit further includes a pore fluid collection device for collecting chemical characteristic parameters of rocks in oil and gas fields with different depletion causes;

[0026] The gas storage reservoir stability evaluation module is also used for gas storage reservoir stability evaluation when the calorific value of combustion at different temperatures in the pore fluid sample is lower than the theoretical calorific value.

[0027] Furthermore, the gas storage reservoir monitoring parameter measurement platform simultaneously collects information on gas storage reservoir monitoring parameters, reservoir brittleness data, pore fluids and their occurrence states, and chemical characteristic parameters of rocks.

[0028] Furthermore, the gas storage reservoir monitoring parameter measurement platform for collecting chemical characteristic parameters of rocks is connected to a big data analysis edge computing gateway and a fluid viscosity and density supervision device; the fluid viscosity and density supervision device collects fluid viscosity and density data of the pore fluid collection device and transmits it to the big data analysis edge computing gateway, and the big data analysis edge computing gateway judges whether pore connectivity occurs based on the received fluid viscosity and density data. When it is judged that pore connectivity occurs, it controls the gas storage reservoir monitoring parameter measurement platform to measure the pore diameter and then perform finite element analysis of the pore fluid.

[0029] Beneficial effects:

[0030] The present invention provides a method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir. Aiming at the impact on the environment during the depletion process of oil and gas fields, the technology of the measurement platform for monitoring parameters of the gas storage reservoir is applied to the exploitation and exploration process to collect the information of monitoring parameters of the gas storage reservoir, reservoir brittleness data, pore fluid and its occurrence state, improving the comprehensive data collection ability during the oil and gas exploitation process and ensuring the stability of data collection. The present invention collects relevant downhole information, calculates the Pearson correlation coefficient and analyzes the bidirectional coupling mechanical model for the collected downhole information. When the reservoir brittleness or the pore fluid and its occurrence state exceed the preset reference stability coefficient, the stability evaluation of the gas storage reservoir is carried out. When it does not exceed the preset reference stability coefficient, the bidirectional coupling mechanical model analysis is carried out on the changes of oil and gas fields with different depletion reasons, assisting oil and gas field engineers to timely discover the changes in the stability of the gas storage reservoir and potential unstable factors. The present invention provides a basis for engineers to optimize the exploitation link, improves the utilization efficiency of oil and gas field resources, and also ensures the exploitation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is the first flow chart of a method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir;

[0032] Figure 2 It is the second flow chart of a method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The following further describes the present application in detail with reference to the drawings and specific embodiments.

[0034] As Figure 1 shown, a method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir according to the present invention has the following specific implementation process:

[0035] S1. Use the measurement platform for monitoring parameters of the gas storage reservoir to collect the information of monitoring parameters of the gas storage reservoir, pore fluid and its occurrence state, reservoir brittleness data of oil and gas fields with different depletion reasons, and collect the chemical property parameters of rocks.

[0036] S2. The measurement platform for monitoring parameters of the gas storage reservoir transmits the collected information of monitoring parameters of the gas storage reservoir, pore fluid and its occurrence state, and reservoir brittleness data back to the big data analysis edge computing gateway.

[0037] S3. First, in this big data analysis edge computing gateway, judge the pore fluid, its occurrence state value, and the reservoir brittleness value. If at least one of the pore fluid and its occurrence state or the reservoir brittleness exceeds its corresponding preset reference stability coefficient, directly start the gas storage reservoir stability evaluation module, estimate the remaining oil and gas content, and investigate potential safety hazards in the mining environment or optimize the mining process;

[0038] S4. If neither the pore fluid and its occurrence state nor the reservoir brittleness exceeds its corresponding preset reference stability coefficient, perform gas storage reservoir monitoring parameter information processing. Use pore pressure data, geological stress data, and generate a two-way coupled rock formation structure model for oil and gas fields with different depletion reasons underground. Then, combined with the collected pore fluid, its occurrence state, and reservoir brittleness data, use numerical calculation methods to analyze the permeability change trend of the geological structure of oil and gas fields with different depletion reasons underground through a numerical two-way coupled mechanical model to obtain the analysis results of the two-way coupled mechanical model.

[0039] In the calculation method of analyzing the permeability change trend of the geological structure of oil and gas fields with different depletion reasons underground through a numerical two-way coupled mechanical model, the present invention does not adopt the common multi-modal fusion calculation method for reservoir brittleness and the stability of gas storage reservoirs in depleted formations because this calculation method not only has difficult data matching but also a long calculation time, and cannot meet the changing environment of oil and gas fields with different depletion reasons underground at all times; Therefore, in order to be able to quickly and accurately analyze the change process of the environment through a two-way coupled mechanical model, the present invention uses the following Figure 2 shown calculation process:

[0040] S4.1. Use the gas storage reservoir monitoring parameter information to construct a two-way coupled rock formation structure model for oil and gas fields with different depletion reasons underground and classify the oil and gas reserve volume in depleted formations;

[0041] S4.2. In the two-way coupled rock formation structure model, set the limited interval of geological and environmental coefficients and the geological stress concentration coefficient of the stability of depleted formations;

[0042] S4.3. Use Darcy's law method to calculate the flow behavior of pore fluid to obtain the medium type; in this process, different dimensional geological stress models under different rock formations are used for the geological stress model;

[0043] S4.4. In the two-way coupled rock formation structure model, set the safety reference, limited interval of the formation pressure coefficient and permeability coefficient of the comprehensive gas storage reservoir stability in depleted formations, and the geological stress concentration coefficient of the stability of depleted formations;

[0044] S4.5. Use the obtained medium type as a characteristic dimension for evaluating the reservoir stability of depleted formation gas storage reservoirs. When performing safety evaluations using the reservoir stability and brittleness of depleted formation gas storage reservoirs, it includes a ground stress model, a seepage model, and a reservoir failure model.

[0045] Output the results of the safety evaluation. This result serves as the basis for studying and analyzing the environmental impact during the exploitation process and provides a reference for optimizing the exploitation process in the later stage.

[0046] The data analysis visualization software outputs the prediction results for the reference of oil and gas field engineers. The oil and gas field engineers can also optimize the exploitation process and progress based on the prediction results.

[0047] While the above work process is in progress, the measurement platform for reservoir monitoring parameters of the gas storage reservoir continuously collects the chemical property parameters of the rock during flight. After the deformation of the chemical property parameter acquisition device of the rock, the oil and gas field engineers take down the collected chemical property parameters of the rock for moisture content detection to obtain the moisture content distribution. If the moisture content distribution shows that the combustion heat of the chemical property parameters of the rock at different temperatures is lower than the theoretical calorific value, directly start the reservoir stability evaluation module of the gas storage reservoir and the estimation of the remaining oil and gas content. If the combustion heat of the chemical property parameters of the rock at different temperatures is higher than the theoretical calorific value, continue the exploitation according to the progress.

[0048] The present invention uses a measurement platform for reservoir monitoring parameters of the gas storage reservoir to collect real-time downhole data of oil and gas fields with different depletion causes. The analysis module of the oil and gas field drilling platform server quickly identifies local environmental changes and unstable factors caused by exploitation and gives timely feedback to help engineers optimize the plan and eliminate potential damages brought by local environmental changes. This method can effectively enhance the data acquisition ability during the exploitation process of depleted formation of oil and gas fields, ensure the safety of engineers, timely optimize the exploitation process to reduce pollution to the local environment, and also ensure the exploitation safety.

[0049] Furthermore, the present invention also collects the chemical property parameters of the rock. By detecting the chemical property parameters of the rock, it monitors whether the pollution in the environment is greater than the theoretical calorific value. When it is greater than the theoretical calorific value, it timely notifies the on-site personnel to take active measures, thereby timely correcting the environmental pollution situation.

[0050] Furthermore, the measurement platform for reservoir monitoring parameters of the gas storage reservoir simultaneously collects reservoir monitoring parameter information of the gas storage reservoir, reservoir brittleness data, pore fluid and its occurrence state, and pore fluid data; it reduces the volume of the equipment, saves space, and at the same time ensures the synchronization of different data per unit time, avoiding errors caused by data mismatch.

[0051] A method for monitoring the reservoir stability of an oil and gas depleted gas storage reservoir according to the present invention is implemented through different modules, including a measurement platform for monitoring parameters of the gas storage reservoir, an analysis module of the oil and gas field drilling platform server, and an evaluation module for the stability of the gas storage reservoir; a multi-modal device monitoring unit is uploaded on the measurement platform for monitoring parameters of the gas storage reservoir; the analysis module of the oil and gas field drilling platform server includes a big data analysis edge computing gateway and data analysis visualization software.

[0052] The measurement platform for monitoring parameters of the gas storage reservoir is used for underground detection during the exploration of depleted formations in oil and gas fields. Local underground information is collected through a multi-modal device monitoring unit. The local underground information includes information on monitoring parameters of the gas storage reservoir, reservoir brittleness data, pore fluids and their occurrence states, and chemical characteristic parameters of rocks; specifically, information on monitoring parameters of the gas storage reservoir, reservoir brittleness data, pore fluids and their occurrence states of gas storage reservoirs in oil and gas fields with different depletion reasons are collected through the multi-modal device monitoring unit and transmitted to the big data analysis edge computing gateway. The chemical characteristic parameters of rocks in the local air at the construction site are collected through the multi-modal device monitoring unit, and the composition of the pore fluids is subsequently manually inspected.

[0053] The big data analysis edge computing gateway calculates the Pearson correlation coefficient between the received pore fluids and their occurrence states and the preset reference stability coefficient of the pore fluids and their occurrence states, and calculates the Pearson correlation coefficient between the received reservoir brittleness data and the preset reference stability coefficient of the reservoir brittleness. When the pore fluids and their occurrence states are higher than the preset reference stability coefficient of the pore fluids and their occurrence states or the reservoir brittleness is higher than the preset reference stability coefficient of the reservoir brittleness, the evaluation module for the stability of the gas storage reservoir is activated to notify the on-site mining engineers; otherwise, the received information on monitoring parameters of the gas storage reservoir is processed, the magnitudes of the pore pressure and the geological stress are screened from the information on monitoring parameters of the gas storage reservoir, and a two-way coupled rock formation structure model for the underground of oil and gas fields with different depletion reasons is generated. Then, combined with the collected pore fluids and their occurrence states and reservoir brittleness data, a numerical two-way coupled mechanical model analysis of the permeability change trend of the geological structure underground in oil and gas fields with different depletion reasons is carried out using numerical calculation methods to obtain the analysis results of the two-way coupled mechanical model.

[0054] The data analysis visualization software is used to output the analysis results of the two-way coupled mechanical model obtained by the big data analysis edge computing gateway.

[0055] The evaluation module for the stability of the gas storage reservoir is used to evaluate the stability of the gas storage reservoir when the pore fluids and their occurrence states are higher than the preset reference stability coefficient of the pore fluids and their occurrence states or the reservoir brittleness is higher than the preset reference stability coefficient of the reservoir brittleness, and to evaluate the stability of the gas storage reservoir when the calorific value of combustion at different temperatures in the chemical characteristic parameters of the rocks is lower than the theoretical calorific value.

[0056] The preset reference stability coefficient of pore fluids and their occurrence states in oil and gas fields is a key parameter used to describe and evaluate the impact of fluids in pores on the stability of rocks and soils in oil and gas fields. This coefficient takes into account fluid type, saturation, pressure, temperature, chemical environment, and the physical properties of rocks and soils, and is determined through methods such as experiments, field tests, and numerical simulations. Its role is to help engineers and geologists accurately predict and control the stability of rock and soil masses during oil and gas field development, ensuring safe and efficient resource extraction.

[0057] The preset reference stability coefficient of reservoir brittleness in oil and gas fields is a key parameter used to evaluate the brittle characteristics of reservoir rocks, reflecting the possibility of brittle fractures occurring in reservoir rocks during the mining process. This coefficient is determined by analyzing factors such as the mechanical properties, mineral composition, pore structure, and fluid pressure of the rocks. Its role is to help engineers optimize fracturing and stimulation measures, ensuring that the reservoir can effectively release oil and gas resources during development, while avoiding production problems caused by excessive fractures in reservoir rocks.

[0058] The multimodal device monitoring unit includes: geophysical logging equipment, seismic exploration equipment, and downhole measurement equipment;

[0059] Geophysical logging equipment includes: electric logging instruments: measuring parameters such as the resistivity and natural gamma radiation of underground rock formations to help determine rock types and porosity. Acoustic logging instruments: using acoustic wave velocity to measure the mechanical properties of rocks, such as porosity and permeability. Nuclear magnetic resonance logging instruments (NMR): measuring the characteristics of pore fluids in rocks to provide porosity and permeability data. Density logging instruments: measuring rock density to help evaluate reservoir quality. Conductivity logging instruments: used to measure the conductivity of rocks and fluids to help identify fluid types.

[0060] Seismic exploration equipment includes: seismic sources: generating seismic waves, common ones being explosive sources and air gun sources. Seismic geophones (seismographs): recording reflected seismic waves to help draw images of underground structures. Seismic data acquisition systems: used to record and process seismic data to generate underground images. Seismic exploration equipment can analyze the brittleness of reservoirs based on seismic acquisition data.

[0061] Downhole measurement equipment includes: a pressure sensor that measures downhole pressure and monitors changes in reservoir pressure; a temperature sensor that measures downhole temperature and helps evaluate thermodynamic conditions; a flowmeter that measures the fluid flow rate in production wells and injection wells; a well inclinometer that measures the well deviation angle and azimuth to ensure the accuracy of the drilling direction and trajectory; and a downhole camera that provides real-time video images of the downhole to inspect the wellbore condition and identify obstacles. The downhole measurement equipment analyzes the porosity, permeability of reservoir rocks, and the type and distribution of fluids in the pores by collecting detailed geological and physical data. These devices can distinguish the presence of oil, water, and gas, evaluate reservoir characteristics and fluid occurrence states, and thus provide key scientific basis for the development and management of oil and gas fields.

[0062] The measurement platform for monitoring parameters of a gas storage reservoir collects multiple downhole information simultaneously. During the modification process, a fluid viscosity and density monitoring device with a control circuit integration module centered on a big data analysis edge computing gateway and an induction pore fluid collection device is added to the measurement platform for monitoring parameters of a gas storage reservoir responsible for collecting chemical characteristic parameters of rocks. A judgment and analysis program for detecting changes in the fluid viscosity and density of the pore fluid collection device is pre-stored in the big data analysis edge computing gateway. The fluid viscosity, density, or volume data of the collection device is set in the program to determine whether pore connectivity occurs in the pore fluid. When it is judged to occur, the measurement platform for monitoring parameters of the gas storage reservoir is controlled by the program to measure the pore diameter and then perform a finite element analysis of the pore fluid.

[0063] As described above, it is only the best specific implementation mode of the invention, but the protection scope of the invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the invention, as well as the design concept and method, according to the technical solution of the invention, making equivalent substitutions or changes, should be covered by the protection scope of the invention.

Claims

1. A method for monitoring reservoir stability of an oil and gas depleted gas storage facility, characterized in that: include: S1. Use the gas storage reservoir monitoring parameter measurement platform to collect data in the exploration well of the depleted strata of the oil and gas field, and collect the gas storage reservoir monitoring parameter information, pore fluid and its occurrence state and reservoir brittleness data of the oil and gas fields with different depletion reasons; S2, calculating the Pearson correlation coefficient of the pore fluid and its occurrence state with the preset benchmark stability coefficient of the pore fluid and its occurrence state, and calculating the Pearson correlation coefficient of the reservoir brittleness data with the preset benchmark stability coefficient of the reservoir brittleness; S3. When the pore fluid and its occurrence state are higher than the preset benchmark stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness data are higher than the preset benchmark stability coefficient of the reservoir brittleness, the gas storage reservoir stability assessment is carried out; S4. Otherwise, pore pressure data and geological stress data are selected from the reservoir monitoring parameter information of the gas storage reservoir, and the permeability change trend of the geological structure of the oil and gas fields with different depletion reasons is analyzed by numerical bidirectional coupling mechanical model in combination with the pore fluid and its occurrence state and reservoir brittleness data, and the bidirectional coupling mechanical model analysis result is obtained and output; The permeability variation trend of the geological structure of oil and gas fields with different depletion causes is analyzed by numerical bidirectional coupling mechanical model, including: S4.

1. Using the reservoir monitoring parameter information of the gas storage, a two-way coupled rock structure model of the wells of oil and gas fields with different depletion causes is constructed and the volume of oil and gas reserves in the depleted formations is classified; S4.

2. In the bidirectional coupled rock structure model, set the limit intervals of geological and environmental coefficients and the geological stress concentration coefficient of depleted stratum stability; S4.

3. Calculate the flow behavior of pore fluid using Darcy's law method to obtain the medium type; S4.

4. In the bidirectional coupled rock structure model, set the safety benchmark, limit interval and geological stress concentration coefficient of the reservoir stability of the depleted formation comprehensive gas storage reservoir; S4.

5. Use the obtained medium type as the characteristic dimension for evaluating the reservoir stability of depleted formation gas storage, use the reservoir stability and reservoir brittleness of depleted formation gas storage for safety evaluation, and obtain the analysis results of the two-way coupling mechanical model.

2. The method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 1, characterized in that: When calculating the flow behavior of porous fluids, the geostress models used are geostress models of different dimensions under different rock formation distributions, including one-dimensional geostress models, two-dimensional geostress models, and three-dimensional geostress models; when using the reservoir stability and reservoir brittleness of depleted formation gas storage for safety assessment, geostress models, seepage models, and reservoir destruction models are included.

3. The method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 1, characterized in that: The pore pressure data and geological stress data are selected from the gas storage reservoir monitoring parameter information in the following ways: the gas storage reservoir monitoring parameter information is normalized by using the Z-score standardization method, and then the fluid and formation temperature are selected from the normalized gas storage reservoir monitoring parameter information by using the principal component analysis algorithm, and the fluid and formation temperature are evaluated by using the finite element analysis model.

4. The method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 1, characterized in that: Also includes: The gas storage reservoir monitoring parameter measurement platform is used to collect data in the exploration wells of depleted strata in the oil and gas fields. The chemical property parameters of the rocks in the oil and gas fields with different depletion reasons are collected, and the water content of the collected chemical property parameters of the rocks is tested to obtain the water content distribution. If the water content distribution shows that the combustion heat at different temperatures in the chemical property parameters of the rocks is lower than the theoretical calorific value, the gas storage reservoir stability assessment and remaining oil and gas content estimation are carried out. If the combustion heat at different temperatures in the chemical property parameters of the rocks is higher than the theoretical calorific value, mining continues according to the schedule.

5. A method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to any one of claims 1 to 4, characterized in that: The method is implemented through different modules, including: a gas storage reservoir monitoring parameter measurement platform, an oil and gas field drilling platform server analysis module and a gas storage reservoir reservoir stability evaluation module; the gas storage reservoir reservoir monitoring parameter measurement platform is loaded with a multi-modal equipment monitoring unit; The gas storage reservoir monitoring parameter measurement platform is used for downhole detection in the exploration of depleted strata in oil and gas fields. The multi-modal equipment monitoring unit collects the gas storage reservoir monitoring parameter information, reservoir brittleness data, pore fluid and its occurrence state of oil and gas fields with different depletion reasons, and transmits the gas storage reservoir monitoring parameter information, reservoir brittleness data, pore fluid and its occurrence state to the oil and gas field drilling platform server analysis module; The oil and gas field drilling platform server analysis module is used to calculate the Pearson correlation coefficient between the received pore fluid and its occurrence state and the preset benchmark stability coefficient of the pore fluid and its occurrence state, and calculate the Pearson correlation coefficient between the received reservoir brittleness data and the preset benchmark stability coefficient of the reservoir brittleness. When the pore fluid and its occurrence state are higher than the preset benchmark stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness data are higher than the preset benchmark stability coefficient of the reservoir brittleness, the gas storage reservoir stability evaluation module is started. Otherwise, the pore pressure data and geological stress data are selected from the gas storage reservoir monitoring parameter information, and the permeability change trend of the geological structure of the oil and gas fields with different depletion reasons is analyzed by a numerical two-way coupling mechanical model in combination with the pore fluid and its occurrence state and the reservoir brittleness data, and the two-way coupling mechanical model analysis results are obtained and output; The gas storage reservoir stability assessment module is used to assess the gas storage reservoir stability when the pore fluid and its occurrence state are higher than the preset benchmark stability coefficient of the pore fluid and its occurrence state or the reservoir brittleness is higher than the preset benchmark stability coefficient of the reservoir brittleness.

6. A method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 5, characterized in that: The multi-modal equipment monitoring unit includes: geophysical logging equipment, seismic exploration equipment and downhole measurement equipment; Geophysical logging equipment is used to collect reservoir monitoring parameter information of gas storage facilities of oil and gas fields with different depletion causes and transmit it to the analysis module of the oil and gas field drilling platform server; seismic exploration equipment is used to collect reservoir brittleness data of oil and gas fields with different depletion causes and transmit it to the analysis module of the oil and gas field drilling platform server; downhole measurement equipment is used to collect geological and physical data of oil and gas fields with different depletion causes, analyze pore fluids and their occurrence states, and transmit them to the analysis module of the oil and gas field drilling platform server.

7. The method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 5, characterized in that: The multimodal equipment monitoring unit also includes a pore fluid acquisition device for acquiring chemical characteristic parameters of rocks in oil and gas fields with different depletion causes; The gas storage reservoir stability evaluation module is also used to evaluate the stability of the gas storage reservoir when the combustion heat at different temperatures in the pore fluid sample is lower than the theoretical calorific value.

8. The method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 7, characterized in that: The gas storage reservoir monitoring parameter measurement platform simultaneously collects gas storage reservoir monitoring parameter information, reservoir brittleness data, pore fluid and its occurrence state, and chemical characteristic parameters of rocks.

9. A method for monitoring reservoir stability of an oil and gas depleted gas storage facility according to claim 8, characterized in that: The gas storage reservoir monitoring parameter measurement platform that collects the chemical property parameters of rocks is connected to the big data analysis edge computing gateway and the fluid viscosity and density monitoring equipment; the fluid viscosity and density monitoring equipment collects the fluid viscosity and density data of the pore fluid collection device and transmits it to the big data analysis edge computing gateway, and the big data analysis edge computing gateway determines whether the pore fluid has pore connectivity based on the received fluid viscosity and density data. When it is judged that it does, it controls the gas storage reservoir monitoring parameter measurement platform to measure the pore diameter and then perform finite element analysis of the pore fluid.

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