Reservoir injection-production capacity experimental evaluation device and method

Abstract

The invention belongs to the technical field of oil and gas field development engineering, and discloses a reservoir injection-production capacity experimental evaluation device and method.The device comprises a pressurization unit, a gas flowmeter set, a simulation unit and a pressure return unit which are sequentially connected; the simulation unit is also connected with a confining pressure unit; the simulation unit is also connected in parallel with a differential pressure sensor group; the simulation unit is sequentially connected with a second pressure reducing valve and a container; the pressurization unit, the simulation unit, the confining pressure unit, the back pressure unit and the differential pressure sensor are in signal connection with the control unit. According to the device and the method, the actual injection-production production characteristics of the gas storage can be simulated, the problems that an existing effective stress pressurization mode does not conform to the actual situation and the reservoir state is not changed are solved, the influence of the gas storage injection-production production on the reservoir can be accurately evaluated, and the reliability of the reservoir is improved. The blank that no device and method for evaluating the influence of underground gas storage (hereinafter referred to as gas storage) injection-production on the reservoir exists at present is filled.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development engineering, and in particular to a device and method for experimental evaluation of reservoir injection and production capacity. Background Art

[0002] In recent years, with the rapid growth of natural gas consumption, the contradiction between insufficient gas storage capacity and a safe and stable natural gas supply has further intensified. Underground gas storage (hereinafter referred to as "gas storage"), as the "ballast stone" that ensures the safe and stable operation of the natural gas energy market, plays an indispensable role in the entire natural gas industry chain. According to international experience, once natural gas external dependence exceeds 30%, the working gas volume of the gas storage facility must exceed 12% of consumption. Furthermore, carbon capture, utilization, and storage (CCS) technology is a new development trend in CCS. CCS technology primarily consists of four steps: capture, transportation, geological storage and monitoring, and enhanced oil recovery. Carbon sequestration is the process of capturing and storing atmospheric carbon dioxide. Currently, the goal of any carbon sequestration project worldwide is to safely store carbon dioxide in formations for hundreds or thousands of years to mitigate the impact of global climate change. Countries around the world are considering using depleted oil and gas reservoirs as CO2 storage for long-term CO2 storage. However, complex geological conditions make new gas storage facilities difficult, risky to operate, and expensive to construct. To improve the gas storage and peak-shaving capacity of gas storage facilities, we should not only focus on quantitative construction, but also strengthen the exploration of the potential of existing gas storage facilities to ensure their efficient operation.

[0003] Gas storage production must be completed within a short period of time (generally, injection within eight months and production within four months), forming an injection-production cycle. This repeated cycle, known as multi-cycle injection-production, involves large gas volumes. This high rate of injection and production within a short period of time causes cyclical changes in reservoir temperature, thermal expansion and contraction of the reservoir rock, and consequently, cyclical changes in reservoir volume. While the pressure of the overlying reservoir remains constant, during injection, the reservoir pore pressure increases until it reaches the upper operating pressure limit, reducing the effective reservoir stress. During production, the reservoir pore pressure decreases until it reaches the lower operating pressure limit, increasing the effective reservoir pressure. Therefore, during the injection and production processes, the reservoir rock experiences cyclical changes in effective stress, temperature, and fluid direction, inevitably leading to changes in reservoir seepage characteristics. This, in turn, affects the reservoir's injection-production capacity and storage capacity, hindering its efficient operation. Therefore, to accurately evaluate the impact of multi-cycle injection-production on the reservoir's injection-production capacity, it is necessary to simulate the gas storage production process and examine changes in reservoir seepage capacity.

[0004] Existing experimental evaluation devices use a constant internal pressure and variable confining pressure to load effective pressure. This loading method differs from actual gas storage production, where the overlying formation pressure remains constant (constant confining pressure) while the pore pressure of the reservoir changes during injection and production (variable internal pressure). The experimental temperature is set to a constant value, the initial reservoir temperature, which differs from actual gas storage production, where the reservoir temperature decreases during injection and increases during production. The experimental medium flows unidirectionally to test the permeability of the reservoir core, whereas in actual gas storage injection and production, the medium (natural gas) flows in opposite directions. Therefore, the reservoir state simulated by existing experimental devices differs from the reservoir state during actual injection and production, making it difficult to accurately evaluate the extent of reservoir damage caused by multi-cycle injection and production. A comprehensive experimental evaluation device and method based on the multi-cycle injection and production characteristics of gas storage is lacking.

[0005] Therefore, it is urgent to design experimental evaluation equipment and methods for reservoir injection and production capacity to provide experimental technical support for formulating efficient injection and production plans for gas storage facilities. Summary of the Invention

[0006] In order to overcome the defects of the above-mentioned prior art, the purpose of this application is to provide a reservoir injection and production capacity experimental evaluation device and method for accurately evaluating the impact of gas storage injection and production on the reservoir, providing experimental technical support for the formulation of efficient injection and production plans for gas storage, and at the same time, it has important guiding significance and experience reference for other gas storages to formulate efficient injection and production plans.

[0007] To achieve the above objectives, this application provides the following technical solutions:

[0008] A reservoir injection and production capacity experimental evaluation device includes a booster unit, a gas flow meter group, a simulation unit and a back pressure unit connected in sequence;

[0009] The booster unit is used to boost the pressure of the simulation unit to simulate the injection and production pressure of the gas storage reservoir;

[0010] The gas flow meter group is used to detect the gas flow from the booster unit to the simulation unit;

[0011] The simulation unit is used to clamp the experimental core and simulate the temperature and pressure conditions of the gas storage reservoir core;

[0012] The back pressure unit is used to adjust the back pressure of the simulation unit;

[0013] The simulation unit is also connected to a confining pressure unit, which is used to adjust the confining pressure of the simulation unit;

[0014] The simulation unit is also connected in parallel with a differential pressure sensor group;

[0015] The simulation unit is also connected in sequence to a second pressure reducing valve and a container;

[0016] The signals of the boosting unit, simulation unit, confining pressure unit, back pressure unit and differential pressure sensor group are connected to the control unit, which is used to control and record the gas pressure of the boosting unit, the heating temperature of the simulation unit, the pressure of the confining pressure unit and the pressure of the back pressure unit.

[0017] Furthermore, the boosting unit includes a nitrogen bottle, a first pressure reducing valve, a gas boosting pump and a first pressure gauge which are connected in sequence.

[0018] Furthermore, the gas flow meter group includes a plurality of gas flow meters with different flow ranges connected in parallel;

[0019] The differential pressure sensor group includes a plurality of differential pressure sensors with different pressure differential ranges connected in parallel.

[0020] Furthermore, the simulation unit includes a core holder, which is a hollow pressure-resistant cylinder;

[0021] The outer surface of the core holder is wrapped with a heating jacket;

[0022] A temperature sensor hole is provided on the wall of the core holder for installing a temperature sensor;

[0023] The heating jacket and temperature sensor signals are connected to the control unit.

[0024] Furthermore, both ends of the core holder are connected to a conversion module, and the conversion module converts the medium inlet and outlet of the core holder through pipelines and valves.

[0025] Furthermore, the confining pressure unit includes a confining pressure pump, which is connected to the core holder through a pipeline, and the confining pressure pump signal is connected to the control unit.

[0026] Furthermore, the back pressure unit includes a back pressure pump, which is connected to the core holder via a pipeline. A second pressure gauge is also provided on the pipeline connecting the back pressure pump and the core holder.

[0027] On the other hand, the present application discloses a method for experimental evaluation of reservoir injection and production capacity, which realizes the evaluation of reservoir injection and production capacity based on the above-mentioned device.

[0028] Furthermore, the evaluation method includes calculating the overlying gas storage pressure and setting the experimental confining pressure based on the drilling and completion data of injection and production wells at each structural point of the gas storage reservoir;

[0029] The experimental injection and production pressure, experimental back pressure and experimental temperature are set based on the actual injection and production wellhead pressure, downhole pressure and reservoir temperature of the gas storage;

[0030] The experimental cores are prepared by using the cores of the reservoirs or the columnar cores obtained from the injection and production wells of the gas storage reservoir;

[0031] The control unit is used to set the experimental injection and production pressure, experimental back pressure, experimental confining pressure, and experimental temperature. By keeping the experimental confining pressure constant, the experimental back pressure is adjusted over multiple cycles to simulate the injection and production process, and the permeability of the injection and production process in each cycle is collected.

[0032] Based on the ratio of the permeability of each injection and production cycle to the initial permeability, the impact of the gas storage on the injection and production capacity of the reservoir during the injection and production process of the corresponding cycle is characterized.

[0033] Furthermore, by controlling the experimental confining pressure to remain constant, the experimental back pressure is adjusted over multiple cycles to simulate the gas injection and production process, including:

[0034] By controlling the experimental confining pressure to remain constant, the experimental back pressure is gradually increased from the lower limit pressure of the gas storage production to the upper limit pressure, and the experimental temperature is gradually reduced from the gas storage reservoir temperature to the lowest temperature monitored during gas injection in the gas storage, simulating the gas injection process of the gas storage;

[0035] By controlling the experimental confining pressure, keeping the experimental back pressure and experimental temperature constant, the equilibrium period of the injection-production conversion period is simulated;

[0036] By keeping the experimental confining pressure constant and using the conversion module to convert the direction of fluid medium movement, the experimental back pressure is gradually reduced from the upper limit pressure of the gas storage to the lower limit pressure, and the experimental temperature is gradually increased to the reservoir temperature of the gas storage to simulate the gas production process of the gas storage.

[0037] Furthermore, based on the ratio of the permeability of each injection and production cycle to the initial permeability, the impact of the gas storage on the reservoir injection and production capacity during the corresponding injection and production cycle is characterized, including:

[0038] When the ratio is greater than or equal to 0 and less than 0.25, the evaluation result of the reservoir injection-production capacity is weak;

[0039] When the ratio is greater than or equal to 0.25 and less than 0.5, the evaluation result of the reservoir injection-production capacity is medium to weak;

[0040] When the ratio is greater than or equal to 0.5 and less than 0.75, the evaluation result of the reservoir injection and production capacity is medium to strong;

[0041] When the ratio is greater than or equal to 0.75 and less than or equal to 1, the evaluation result of the reservoir injection-production capacity is strong.

[0042] Furthermore, the gas storage includes a natural gas storage and a carbon dioxide storage, and the carbon dioxide storage is used to inject carbon dioxide into the ground for geological storage.

[0043] The technical effects and advantages of this application are:

[0044] 1. This application provides a reservoir injection and production capacity experimental evaluation device, which simulates the actual injection and production characteristics of a gas storage facility, solves the problem that the existing effective stress pressurization method does not conform to the actual situation and the reservoir state remains unchanged, and can accurately evaluate the impact of the gas storage facility's injection and production on the reservoir, filling the gap in the current lack of a reservoir impact evaluation device for gas storage facility injection and production.

[0045] 2. This application provides reliable and effective experimental technical support for the systematic study of gas storage reservoir seepage mechanism, storage capacity change law, efficient injection and production measures, etc., and provides scientific and technological support and technical guarantee for the formulation of efficient injection and production plans.

[0046] 3. The experimental results of this application on the evaluation of the impact of gas storage injection and production on the reservoir can provide important experimental data support for production pressure difference control and storage capacity expansion during the operation of the gas storage, and have good market demand and prospects.

[0047] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures indicated in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the structure of the reservoir injection and production capacity experimental evaluation device of this application;

[0049] Figure 2 This is a flow chart of the reservoir injection-production capacity experimental evaluation method of this application.

[0050] Figure numerals: 1. nitrogen cylinder; 2. first pressure reducing valve; 3. gas booster pump; 4. first pressure gauge; 5. gas flow meter group; 6. heating jacket; 7. core holder; 8. confining pressure pump; 9. second pressure gauge; 10. back pressure pump; 11. second pressure reducing valve; 12. container; 13. control unit; 14. A valve; 15. G valve; 16. K valve; 17. C valve; 18. J valve; 19. E valve; 20. F valve; 21. differential pressure sensor group; 22. I valve; 23. B valve; 24. D valve; 25. H valve. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0052] On the one hand, the present application provides a reservoir injection and production capacity experimental evaluation device, comprising a booster unit, a gas flow meter group 5, a simulation unit and a back pressure unit connected in sequence;

[0053] The booster unit is used to boost the pressure of the simulation unit to simulate the injection and production pressure of the gas storage reservoir;

[0054] The gas flow meter group 5 is used to detect the gas flow from the booster unit to the simulation unit;

[0055] The simulation unit is used to clamp the experimental core and simulate the temperature and pressure conditions of the gas storage reservoir core;

[0056] The back pressure unit is used to adjust the back pressure of the simulation unit;

[0057] The simulation unit is also connected to a confining pressure unit, which is used to adjust the confining pressure of the simulation unit;

[0058] The simulation unit is also connected in parallel with a differential pressure sensor group 21;

[0059] The simulation unit is also connected in sequence to the second pressure reducing valve 11 and the container 12;

[0060] The boost unit, simulation unit, confining pressure unit, back pressure unit and differential pressure sensor signals are connected to the control unit 13, which is used to control and record the gas pressure of the boost unit, the heating temperature of the simulation unit, the pressure of the confining pressure unit and the pressure of the back pressure unit.

[0061] In some embodiments of the present application, Figure 1 As shown, the boosting unit includes a nitrogen cylinder 1, a first pressure reducing valve 2, a gas boosting pump 3 and a first pressure gauge 4 connected in sequence, and an A valve 14 is also provided between the gas boosting pump 3 and the first pressure gauge 4; the gas flow meter group 5 selects a plurality of gas flow meters with different flow ranges in parallel according to the experimental requirements, for example, 5; the differential pressure sensor group 21 selects a plurality of differential pressure sensors with different pressure differential ranges in parallel according to the experimental requirements, for example, 3 (pressure differential range high, medium and low); the simulation unit includes a core holder 7, which is a hollow pressure-resistant cylinder The outer surface of the core holder 7 is wrapped with a heating jacket 6, and a temperature sensor hole is provided on the wall of the core holder 7 for installing the temperature sensor. The heating jacket 6 and the temperature sensor signals are connected to the control unit 13, and the control unit 13 includes a computer; the confining pressure unit includes a confining pressure pump 8, which is connected to the core holder 7 through a pipeline, and the confining pressure pump 8 signal is connected to the control unit 13; the back pressure unit includes a back pressure pump 10, which is connected to the core holder 7 through a pipeline, and a second pressure gauge 9 is also provided on the pipeline connecting the back pressure pump 10 and the core holder 7.

[0062] The two ends of the core holder 7 are connected to the conversion module, which converts the medium inlet and outlet of the core holder 7 through pipelines and valves. Specifically, the conversion module is as follows: Figure 1 As shown, the gas flow meter group 5 and the core holder 7 are connected through the first pipeline, the core holder 7 and the back pressure pump 10 are connected through the second pipeline and the third pipeline in series, the core holder 7 and the container 12 are connected through the second pipeline and the fourth pipeline in series, the core holder 7 and the confining pressure pump 8 are connected through the fifth pipeline, the two ends of the core holder 7 and the two ends of the differential pressure sensor group 21 are connected through the sixth pipeline and the seventh pipeline respectively, the first pipeline is provided with a B valve 23, the second pipeline is provided with a C valve 17 and a D valve 24, the third pipeline is provided with an E valve 19, the fourth pipeline is provided with an F valve 20, the fifth pipeline is provided with a G valve 15, and the sixth pipeline is provided with an H valve. 25, the sixth pipeline is connected to the second pipeline through the eighth pipeline, the eighth pipeline is provided with an I valve 22, one end of the eighth pipeline is connected between the H valve 25 and the core clamp 7, and the other end of the eighth pipeline is connected to the end of the second pipeline away from the core clamp 7. The first pipeline is connected to the second pipeline through the ninth pipeline, the ninth pipeline is provided with a J valve 18, one end of the ninth pipeline is connected between the gas flow meter group 5 and the B valve 23, and the other end of the ninth pipeline is connected between the C valve 17 and the D valve 24. The fifth pipeline is connected to the outside world through the tenth pipeline, the tenth pipeline is provided with a K valve 16, and the connection between the tenth pipeline and the fifth pipeline is located between the G valve 15 and the confining pressure pump 8.

[0063] On the other hand, the present application also discloses a reservoir injection and production capacity experimental evaluation method, which is based on the above-mentioned device to evaluate the reservoir injection and production capacity, such as Figure 2 Shown, including:

[0064] Based on the drilling and completion data of injection and production wells at each structural point of the gas storage reservoir, the overlying gas storage reservoir pressure is calculated as the experimental confining pressure;

[0065] The experimental injection and production pressure, experimental back pressure and experimental temperature are set based on the actual injection and production wellhead pressure, downhole pressure and reservoir temperature of the gas storage;

[0066] The experimental cores are prepared by using the reservoir cores or reservoir outcrops of the gas storage injection and production wells to obtain columnar cores;

[0067] The control unit 13 is used to set the experimental injection and production pressure, experimental back pressure, experimental confining pressure and experimental temperature. By keeping the experimental confining pressure constant, the experimental back pressure is adjusted in multiple cycles to simulate the injection and production process, and the permeability of the injection and production process in each cycle is collected;

[0068] Based on the ratio of the permeability of each injection and production cycle to the initial permeability, the impact of the gas storage on the injection and production capacity of the reservoir during the injection and production process of the corresponding cycle is characterized.

[0069] In some embodiments of the present application, the gas injection and production process is simulated by controlling the experimental confining pressure to remain constant and adjusting the experimental back pressure over multiple cycles, including:

[0070] By controlling the experimental confining pressure to remain constant, the experimental back pressure is gradually increased from the lower limit pressure of the gas storage production to the upper limit pressure, and the experimental temperature is gradually reduced from the gas storage reservoir temperature to the lowest temperature monitored during gas injection in the gas storage, simulating the gas injection process of the gas storage;

[0071] By controlling the experimental confining pressure, keeping the experimental back pressure and experimental temperature constant, the equilibrium period of the injection-production conversion period is simulated;

[0072] By keeping the experimental confining pressure constant and using the conversion module to convert the direction of fluid medium movement, the experimental back pressure is gradually reduced from the upper limit pressure of the gas storage to the lower limit pressure, and the experimental temperature is gradually increased to the reservoir temperature of the gas storage to simulate the gas production process of the gas storage.

[0073] In some embodiments of the present application, based on the ratio of the permeability of each gas injection and production cycle to the initial permeability, the impact of the gas storage on the reservoir injection and production capacity during the corresponding injection and production cycle is characterized, including:

[0074] When the ratio is greater than or equal to 0 and less than 0.25, the evaluation result of the reservoir injection-production capacity is weak;

[0075] When the ratio is greater than or equal to 0.25 and less than 0.5, the evaluation result of the reservoir injection-production capacity is medium to weak;

[0076] When the ratio is greater than or equal to 0.5 and less than 0.75, the evaluation result of the reservoir injection and production capacity is medium to strong;

[0077] When the ratio is greater than or equal to 0.75 and less than or equal to 1, the evaluation result of the reservoir injection-production capacity is strong.

[0078] In some embodiments of the present application, the gas storage reservoir includes a natural gas storage reservoir and a carbon dioxide storage reservoir, and the carbon dioxide storage reservoir is used to inject carbon dioxide into the ground for geological storage.

[0079] In order to better illustrate this solution, the following examples are also provided.

[0080] Example

[0081] S1: Collect and organize the logging data of injection and production wells at each structural point of the gas storage reservoir, calculate the density and depth of each overlying stratum, and calculate the experimental confining pressure to be 67MPa. The calculation formula is as follows:

[0082]

[0083] Where: P—experimental confining pressure, MPa; H—formation depth, m; ρ(h)—formation density at depth h, g / cm3 ; g—gravitational acceleration, N / kg, z is the burial depth of the rock, m.

[0084] S2: Collect and organize the actual gas storage wellhead pressure (injection and production pressure), downhole pressure (reservoir pore pressure), and temperature data for the experimental pressure, experimental back pressure, and experimental temperature. The downhole pressure represents the upper and lower operating pressure limits of the gas storage, i.e., downhole pressures from 10.31 MPa to 30.60 MPa. The reservoir pore pressure is broken down into 3 MPa intervals, from a lower limit of 10 MPa to an upper limit of 31 MPa. The downhole pressures are 10 MPa, 13 MPa, 16 MPa, 19 MPa, 22 MPa, 25 MPa, 28 MPa, and 31 MPa, respectively. This means the experimental back pressures are 10 MPa, 13 MPa, 16 MPa, 19 MPa, 22 MPa, 25 MPa, 28 MPa, and 31 MPa.

[0085] The effective stress is calculated using the following formula:

[0086] D=P-Pn

[0087] Where: D is effective stress, MPa; P is experimental confining pressure, MPa; and Pn is downhole pressure, MPa. The calculation results are shown in Table 1 below.

[0088] The experimental temperatures were those monitored during actual injection and production at the gas storage facility: injection temperatures ranged from 37.85°C to 61.89°C; production temperatures ranged from 61.89°C to 37.85°C. During injection, the experimental temperature was decreased from 70°C to 35°C in 5°C increments. During production, the experimental temperature was increased from 35°C to 70°C in 5°C increments. Each temperature point was maintained for 15 minutes. Experimental temperatures were set at 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, and 70°C.

[0089] The experimental pressure difference is calculated based on the actual injection-production pressure difference of the gas storage reservoir. The calculation results are shown in Table 2. The calculation formula is as follows:

[0090] P zc =|P a -P n |

[0091] Where: Pzc—experimental pressure difference, MPa; Pa—wellhead oil pressure, MPa; Pn—downhole pressure, MPa.

[0092] Table 1. Effective stress of gas injection and production in gas storage

[0093]

[0094] Table 2 Gas storage injection and production pressure difference

[0095] Injection-production process Wellhead pressure, MPa Downhole pressure, MPa Injection-production pressure difference, MPa Gas injection period 7.67～25.82 10.31～30.60 2.64～4.78 Gas production period 24.54～2.95 30.60～10.31 6.06～7.36

[0096] In order to ensure the pertinence and accuracy of the experimental research, the experimental pressure difference range was expanded, and the experimental pressure difference values ​​were set to 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, and 9MPa.

[0097] S3: Drill a columnar core from the reservoir of the gas storage injection and production well or the reservoir outcrop, create artificial seams and seal it with a heat shrinkable rubber sleeve to serve as the experimental core, φ2.54 cm × L 5.13 cm.

[0098] S4: Press Figure 1 Set up a reservoir injection and production capacity experimental evaluation device, load the experimental core into the pressure unit, and connect the pipelines at both ends of the pressure unit; stipulate that the left end of the core holder 7 is the initial inlet end of the medium and the right end is the initial outlet end, open valve A 14, valve B 23, valve H 25, valve C 17, valve E 19, valve F 20, valve D 24, close valve J 18 and valve I 22, and check that the valves of the pressure unit are in the correct position.

[0099] S5: Set the experimental confining pressure to 67 MPa and the reservoir temperature to 70°C on the control unit 13. Open the G valve 15, close the K valve 16, start the confining pressure pump 8, and begin linearly loading the experimental confining pressure to the overburden pressure of 67 MPa. Simultaneously, raise the temperature of the simulation unit to the reservoir temperature (initial reservoir temperature), and maintain the experimental confining pressure at 67 MPa and the temperature at 70°C for 2 hours. The linear loading rate of the confining pressure is calculated according to the following formula:

[0100]

[0101] Where: v—confining pressure loading rate, MPa / min;

[0102] p—overlying formation pressure, MPa;

[0103] t—Gas injection time of injection-production cycle experiment, min.

[0104] S6: Set the experimental back pressure points of 10 MPa, 13 MPa, 16 MPa, 19 MPa, 22 MPa, 25 MPa, 28 MPa, and 31 MPa on the control unit 13 in sequence, start linear loading to the experimental back pressure points in sequence, and stabilize the pressure at each experimental back pressure point for 15 minutes.

[0105] S7: Open the nitrogen cylinder 1, start the gas booster pump 3 to increase the pressure to the gas storage reservoir during gas injection and production, and reach the experimental pressure difference value (2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa). Select the matching gas flow meter group 5 according to the flow rate, and select the matching differential pressure sensor group 21 according to the pressure difference change.

[0106] S8: The experimental test begins by gradually increasing the pressure from the lower limit to the upper limit of the gas storage reservoir. The experimental temperature is gradually reduced from the reservoir temperature to the lowest temperature monitored during gas injection. During this process, the pressure is stabilized at each point for 15 minutes, and then the permeability is continuously collected. This process represents the gas injection process of the gas storage reservoir. The changes in permeability with injection pressure and temperature are shown in Table 3 below.

[0107] S9: After the gas injection process is completed, the injection pressure and temperature are maintained constant for 1 hour. This process is the equilibrium period of the injection-production conversion period.

[0108] Table 3 Reservoir permeability changes with injection pressure and temperature during gas injection

[0109]

[0110] Table 4 Reservoir permeability changes with injection pressure and temperature during gas production

[0111]

[0112] S10: After the equilibrium period, valves A 14, J 18, C 17, E 19, F 20, H 25, and I 22 were opened, while valves B 23, D 24, and the medium inlet and outlet of core holder 7 were closed. The pressure was gradually reduced from the upper pressure limit of the gas storage reservoir to the lower pressure limit, and the experimental temperature was gradually increased to the gas storage reservoir temperature. During this process, the pressure was stabilized at each point for 15 minutes, and then the permeability was continuously collected. This process represents the gas production process of the gas storage reservoir. The changes in permeability with injection pressure and temperature are shown in Table 4.

[0113] S11: S8-S10 is one injection-production cycle. Repeating S8-S10 is multi-cycle injection-production. The permeability values ​​of the multi-cycle injection-production process are collected.

[0114] S12: The ratio of the permeability of any period of gas injection and production to the initial permeability is used to characterize the impact of the gas storage on the injection and production capacity of the reservoir at the injection and production time of the period. For example, the initial permeability is 1.062×10 -3 μm 2 The permeability at the end of the first injection-production cycle was 1.041×10 -3 μm 2 The permeability ratio characterizing the reservoir injection and production capacity is 0.98. According to Table 5, the reservoir injection and production capacity evaluation table of gas storage reservoirs shows that the reservoir injection and production capacity is strong at the end of the first injection and production cycle.

[0115] In summary, the present application provides a reservoir injection and production capacity experimental evaluation device, which simulates the actual injection and production characteristics of a gas storage facility, solves the problem that the existing effective stress pressurization method does not conform to the actual situation and the reservoir state remains unchanged, and can accurately evaluate the impact of the gas storage facility's injection and production on the reservoir, filling the gap in the current lack of a device and method for evaluating the impact of gas storage facility injection and production on the reservoir. It is also suitable for natural gas storage production, carbon dioxide storage (for injecting carbon dioxide underground for geological storage) production, and the evaluation of the impact of carbon dioxide injection on the reservoir to enhance gas recovery (EGR).

[0116] Table 5 Evaluation table of gas storage reservoir injection and production capacity

[0117]

[0118] Finally, it should be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. Reservoir injection and production capacity experimental evaluation device, characterized in that: It includes a boosting unit, a gas flow meter group (5), a simulation unit and a back pressure unit connected in sequence; The boosting unit is used to boost the pressure of the simulation unit to simulate the injection and production pressure of the gas storage reservoir; The gas flow meter group (5) is used to detect the gas flow from the boosting unit to the simulation unit; The simulation unit is used to clamp the experimental core and simulate the temperature and pressure conditions of the gas storage reservoir core; The back pressure unit is used to adjust the back pressure of the simulation unit; The simulation unit is also connected to a confining pressure unit, and the confining pressure unit is used to adjust the confining pressure of the simulation unit; The simulation unit is also connected in parallel with a differential pressure sensor group (21); The simulation unit is also connected in sequence to a second pressure reducing valve (11) and a container (12); The boost unit, simulation unit, confining pressure unit, back pressure unit and differential pressure sensor group (21) are connected to a control unit (13) via signals. The control unit (13) is used to control and record the gas pressure of the boost unit, the heating temperature of the simulation unit, the pressure of the confining pressure unit and the pressure of the back pressure unit.

2. The reservoir injection and production capacity experimental evaluation device according to claim 1, characterized in that: The boosting unit comprises a nitrogen bottle (1), a first pressure reducing valve (2), a gas boosting pump (3) and a first pressure gauge (4) which are connected in sequence.

3. The reservoir injection and production capacity experimental evaluation device according to claim 1, characterized in that: The gas flow meter group (5) includes a plurality of gas flow meters connected in parallel; The differential pressure sensor group (21) includes a plurality of differential pressure sensors connected in parallel.

4. The reservoir injection and production capacity experimental evaluation device according to claim 1, characterized in that: The simulation unit comprises a core holder (7), which is a hollow pressure-resistant cylinder; The outer surface of the core holder (7) is wrapped with a heating jacket (6); A temperature sensor hole is provided on the wall of the core holder (7) for installing a temperature sensor; The heating jacket (6) and the temperature sensor signals are connected to the control unit (13).

5. The reservoir injection and production capacity experimental evaluation device according to claim 4, characterized in that: Both ends of the core holder (7) are connected to a conversion module, and the conversion module converts the medium inlet and outlet of the core holder (7) through pipelines and valves.

6. The reservoir injection and production capacity experimental evaluation device according to claim 4, characterized in that: The confining pressure unit comprises a confining pressure pump (8), the confining pressure pump (8) is connected to the core holder (7) via a pipeline, and the confining pressure pump (8) is connected to the control unit (13) via a signal.

7. The reservoir injection and production capacity experimental evaluation device according to claim 4, characterized in that: The back-pressure unit comprises a back-pressure pump (10), the back-pressure pump (10) is connected to the core holder (7) via a pipeline, and a second pressure gauge (9) is further provided on the pipeline connecting the back-pressure pump (10) and the core holder (7).

8. A reservoir injection-production capacity experimental evaluation method, characterized in that: The method realizes the injection-production capacity evaluation of the reservoir based on the device described in any one of claims 1 to 7.

9. The reservoir injection-production capacity experimental evaluation method according to claim 8, characterized in that: include: Based on the drilling and completion data of injection and production wells at each structural point of the gas storage reservoir, the overlying gas storage reservoir pressure is calculated as the experimental confining pressure; The experimental injection and production pressure, experimental back pressure and experimental temperature are set based on the actual injection and production wellhead pressure, downhole pressure and reservoir temperature of the gas storage; The experimental cores are prepared by using the cores of the reservoirs or the columnar cores obtained from the injection and production wells of the gas storage reservoir; Using a control unit (13) to set experimental injection and production pressure, experimental back pressure, experimental confining pressure and experimental temperature, by controlling the experimental confining pressure to remain constant, adjusting the experimental back pressure over multiple cycles to simulate the injection and production process, and collecting the permeability of the injection and production process in each cycle; Based on the ratio of the permeability of each injection and production cycle to the initial permeability, the impact of the gas storage on the injection and production capacity of the reservoir during the injection and production process of the corresponding cycle is characterized.

10. The reservoir injection-production capacity experimental evaluation method according to claim 9, characterized in that: The method of simulating the gas injection and production process by controlling the experimental confining pressure to be constant and adjusting the experimental back pressure over multiple cycles includes: By controlling the experimental confining pressure to remain constant, the experimental back pressure is gradually increased from the lower limit pressure of the gas storage production to the upper limit pressure, and the experimental temperature is gradually reduced from the gas storage reservoir temperature to the lowest temperature monitored during gas injection in the gas storage, simulating the gas injection process of the gas storage; By controlling the experimental confining pressure, keeping the experimental back pressure and experimental temperature constant, the equilibrium period of the injection-production conversion period is simulated; By keeping the experimental confining pressure constant and using the conversion module to convert the direction of fluid medium movement, the experimental back pressure is gradually reduced from the upper limit pressure of the gas storage to the lower limit pressure, and the experimental temperature is gradually increased to the reservoir temperature of the gas storage to simulate the gas production process of the gas storage.

11. The reservoir injection-production capacity experimental evaluation method according to claim 9, characterized in that: The ratio of the permeability during each gas injection and production cycle to the initial permeability based on the data collected represents the impact of the gas storage on the injection and production capacity of the reservoir during the injection and production process of the corresponding cycle, including: When the ratio is greater than or equal to 0 and less than 0.25, the evaluation result of the injection-production capacity of the reservoir is weak; When the ratio is greater than or equal to 0.25 and less than 0.5, the evaluation result of the injection-production capacity of the reservoir is medium to weak; When the ratio is greater than or equal to 0.5 and less than 0.75, the evaluation result of the injection-production capacity of the reservoir is medium to strong; When the ratio is greater than or equal to 0.75 and less than or equal to 1, the evaluation result of the injection-production capacity of the reservoir is strong.

12. The reservoir injection-production capacity experimental evaluation method according to any one of claims 8 to 11, characterized in that: The gas storage includes a natural gas storage and a carbon dioxide storage. The carbon dioxide storage is used to inject carbon dioxide into the ground for geological storage.

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