Method and device for determining injection-production capacity of gas storage

Abstract

The invention discloses a method and device for determining the injection-production capacity of a gas storage, and the method comprises the steps: obtaining the reasonable production pressure difference of the gas storage and the development data of the oil reservoir in the development period, solving a Duapi formula according to the first target data of the development data, and obtaining the oil phase permeability; according to second target data of the development data, solving the binomial gas well productivity equation to obtain gas phase permeability, determining gas well gas production capacity according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, and according to the reasonable production pressure difference, performing nitrogen test injection on the gas storage to determine gas well gas injection capacity. Due to the fact that the permeability influence of the oil phase and the gas phase is considered when the gas production capacity of the gas well is determined, the actual situation in the gas storage can be met to the maximum extent through nitrogen injection testing when the gas injection capacity of the gas well is determined, and the gas well injection and production capacity determination applied to the gas cap reservoir type gas storage has more scientific guiding significance; and the accuracy of determining the injection-production capacity of the gas storage is improved.

Description

Technical Field

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

[0002] Gas-cap reservoir-type gas storage is a type of depleted oil and gas reservoir-type gas storage. It is built by using the depleted and abandoned oil and gas reservoirs that have been mined, or by decommissioned oil and gas reservoirs that have been mined to a certain extent. At present, when designing the injection and production capacity of gas wells in gas-cap reservoir-type gas storage at home and abroad, it is usually based on the unstable well test and other field test data to establish the binomial gas well production capacity equation to determine the injection and production capacity of the gas storage.

[0003] The binomial gas well productivity equation is also called LIT analysis (Laminar-inertial-turbulent Flow Analysis), i.e. laminar flow, inertial-turbulent analysis. The node pressure comprehensive evaluation method is used to consider reservoir characteristics, formation seepage, wellbore dynamic gas column, gas erosion, critical liquid carrying, etc., to optimize the gas well type and well diameter, so as to determine the reasonable gas injection and production volume of the gas storage. It was derived by Forchheimer and Houpeurt based on the solution of a flow equation. The binomial coefficients in the binomial gas well productivity equation are the coefficients of the laminar and turbulent flow parts in the reservoir.

[0004] However, the gas cap reservoir type gas storage adopts the development principle of early protection of gas cap energy, avoiding perforation of gas layers and water layers, and preferably putting some oil layers into production. Therefore, the gas in the gas layer is produced by gas channeling, and the influence of liquid on natural gas production capacity needs to be fully considered. When designing the injection and production capacity of gas, the production capacity of the development process calculated only by the binomial gas well production capacity equation will make the calculation results lack scientificity, accuracy and practicality.

[0005] Therefore, how to improve the accuracy of determining the injection and production capacity of gas-cap reservoir-type gas storage is a technical problem that needs to be solved urgently. Summary of the invention

[0006] A method and device for determining the injection and production capacity of a gas storage reservoir of the present invention can improve the accuracy of determining the injection and production capacity of a gas cap reservoir type gas storage reservoir.

[0007] The embodiment of the present invention provides the following solution:

[0008] In a first aspect, an embodiment of the present invention provides a method for determining the injection and production capacity of a gas storage reservoir, which is applied to determining the injection and production capacity of a gas well of a gas cap reservoir type gas storage reservoir, and the method comprises:

[0009] Obtain the reasonable production pressure difference of the gas storage and the development data during the reservoir development period;

[0010] Obtaining the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jubby formula, wherein the first target data is the data required for calculating the oil phase permeability using the Jubby formula;

[0011] According to the second target data of the development data and the binomial gas well productivity equation, the gas phase permeability of the gas storage reservoir is obtained, wherein the second target data is the data required for calculating the gas phase permeability using the binomial gas well productivity equation;

[0012] Determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability;

[0013] The gas storage reservoir is tested for nitrogen injection according to the reasonable production pressure difference to determine the gas injection capacity of the gas wells of the gas storage reservoir.

[0014] In an optional embodiment, determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability includes:

[0015] According to the oil phase permeability, the gas phase permeability and the binomial coefficient equation, a laminar coefficient and a turbulent coefficient are obtained;

[0016] The binomial gas well production capacity equation is solved according to the reasonable production pressure difference, the laminar flow coefficient, the turbulence coefficient and the original formation pressure of the gas storage reservoir to obtain the gas well production to determine the gas production capacity of the gas well.

[0017] In an optional embodiment, obtaining the laminar coefficient and the turbulent coefficient according to the oil phase permeability, the gas phase permeability and the binomial coefficient equation includes:

[0018] Obtaining effective permeability according to the sum of the permeability of the oil phase permeability and the gas phase permeability;

[0019] According to the formula Obtaining the laminar flow coefficient A;

[0020] According to the formula The turbulence coefficient B is obtained, where is the viscosity of natural gas, is the natural gas deviation factor, is the formation temperature, h is the effective reservoir thickness, K is the effective permeability, t is the penetration time, r w is the converted radius of the gas well, φ is the porosity of the gas layer, C t is the comprehensive compression coefficient of the formation, D is the non-Darcy flow coefficient, p sc is the gas pressure under standard conditions, T scis the gas temperature under standard conditions, S a is the apparent skin factor.

[0021] In an optional embodiment, before determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, the method further includes:

[0022] Obtaining a permeability-yield relationship between an effective permeability and a yield index of the gas storage reservoir;

[0023] Performing injection-production phase permeability tests at different cycles on the actual drilled cores of the gas storage to obtain phase permeability curves;

[0024] According to the permeability-production relationship and the phase permeability curve, a gas phase production index and an oil phase production index at each gas saturation in each operation cycle are obtained;

[0025] According to the reasonable production pressure difference, the gas phase production index and the oil phase production index, the maximum gas production of the gas storage in the corresponding operation cycle and the corresponding formation pressure is obtained;

[0026] The maximum gas production volume is determined as the gas production capacity of the gas well.

[0027] In an optional embodiment, after determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, the method further includes:

[0028] Obtain a curve superposition diagram of the gas well IPR inflow curve and the wellbore flow curve;

[0029] Determine the gas production capacity of the gas well using the node analysis in the curve superposition diagram according to the reasonable production pressure difference;

[0030] The gas well gas production capacity of the gas storage is updated according to the gas well gas production capacity analyzed by the application node.

[0031] In an optional embodiment, the step of performing nitrogen test injection on the gas storage according to the reasonable production pressure difference to determine the gas injection capacity of the gas well of the gas storage includes:

[0032] Constructing a gas suction indication curve; wherein the gas suction indication curve is a curve showing the change of nitrogen injection volume following the bottom hole flow pressure;

[0033] Solving the binomial gas well productivity equation for nitrogen injection according to the gas suction indication curve to obtain the test injection laminar coefficient and the test injection turbulence coefficient;

[0034] Correcting the laminar flow coefficient of natural gas according to the test injection laminar flow coefficient, and correcting the turbulence coefficient of natural gas according to the test injection turbulence coefficient;

[0035] The binomial gas well production capacity equation for injecting natural gas is solved according to the reasonable production pressure difference, the laminar flow coefficient and the turbulence coefficient to obtain the gas injection capacity of the gas well.

[0036] In an optional embodiment, the step of correcting the laminar flow coefficient of the natural gas according to the test injection laminar flow coefficient and the step of correcting the turbulence coefficient of the natural gas according to the test injection turbulence coefficient include:

[0037] According to the formula Obtain the corrected laminar flow coefficient A2;

[0038] According to the formula The corrected turbulence coefficient B2 is obtained; where A1 is the test laminar coefficient, B1 is the test turbulence coefficient, μ g1 is the nitrogen flow rate, μ g2 is the natural gas fluidity, Z1 is the nitrogen deviation factor, Z2 is the natural gas deviation factor, K1 is the nitrogen effective permeability, and K2 is the natural gas effective permeability.

[0039] In a second aspect, an embodiment of the present invention further provides a device for determining the injection and production capacity of a gas storage reservoir, which is applied to determine the injection and production capacity of a gas well of a gas cap reservoir type gas storage reservoir, and the device comprises:

[0040] The first acquisition module is used to obtain the reasonable production pressure difference of the gas storage and the development data during the reservoir development period;

[0041] A first obtaining module is used to obtain the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jubby formula, wherein the first target data is the data required to calculate the oil phase permeability using the Jubby formula;

[0042] A second obtaining module is used to obtain the gas phase permeability of the gas storage reservoir according to the second target data of the development data and the binomial gas well productivity equation, wherein the second target data is the data required to calculate the gas phase permeability using the binomial gas well productivity equation;

[0043] A first determination module is used to determine the gas production capacity of the gas well of the gas storage according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability;

[0044] The second determination module is used to perform nitrogen test injection on the gas storage according to the reasonable production pressure difference to determine the gas injection capacity of the gas wells of the gas storage.

[0045] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory is coupled to the processor, and the memory stores instructions, which, when executed by the processor, enable the electronic device to perform the steps of any one of the methods described in the first aspect.

[0046] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods described in the first aspect.

[0047] Compared with the prior art, the method and device for determining the injection and production capacity of a gas storage reservoir of the present invention has the following advantages:

[0048] The determination method of the present invention obtains the reasonable production pressure difference of the gas storage reservoir and the development data during the oil reservoir development period, solves the Jupyter formula according to the first target data of the development data to obtain the oil phase permeability, solves the binomial gas well production capacity equation according to the second target data of the development data to obtain the gas phase permeability, determines the gas well gas production capacity according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, and conducts nitrogen test injection on the gas storage reservoir according to the reasonable production pressure difference to determine the gas well gas injection capacity. Since the influence of the permeability of the oil phase and the gas phase is taken into account when determining the gas well gas production capacity, the nitrogen test injection can be used to maximize the fit of the actual situation inside the gas storage reservoir when determining the gas well gas injection capacity, so that the determination of the gas well injection and production capacity applied to the gas cap oil reservoir type gas storage reservoir has more scientific guiding significance, thereby improving the accuracy of the determination of the gas storage reservoir injection and production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 A flow chart of a method for determining the injection and production capacity of a gas storage provided in an embodiment of the present invention;

[0051] Figure 2 A graph of oil saturation and relative permeability provided in an embodiment of the present invention;

[0052] Figure 3 A schematic diagram of a curve superposition diagram provided by an embodiment of the present invention;

[0053] Figure 4 A step diagram of determining a gas well productivity equation using a nitrogen test injection method provided in an embodiment of the present invention;

[0054] Figure 5 A step diagram of a method for determining the injection and production capacity of a gas storage reservoir provided in an embodiment of the present invention;

[0055] Figure 6 A schematic diagram of the structure of a device for determining the injection and production capacity of a gas storage reservoir provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the embodiments of the present invention.

[0057] At present, the injection and production capacity setting of gas storage facilities only relies on the binomial gas well production capacity equation method to determine the production capacity, which will result in a smaller production capacity of gas wells in gas-cap reservoir-type gas storage facilities, making it impossible to design the injection and production volume of gas wells (or single wells) more scientifically and accurately. The following embodiments of the present invention will specifically explain how to improve the accuracy of determining the injection and production capacity of gas wells in gas-cap reservoir-type gas storage facilities.

[0058] See also Figure 1 , Figure 1 A flow chart of a method for determining the injection and production capacity of a gas storage provided in an embodiment of the present invention is applied to determining the injection and production capacity of a gas well of a gas cap reservoir type gas storage, the method comprising:

[0059] S11. Obtain the reasonable production pressure difference of the gas storage and the development data during the reservoir development period.

[0060] Specifically, the reasonable production pressure difference is the pressure difference between the injection pressure and the outlet pressure during the production process of the gas storage reservoir. Under this pressure difference, the rock inside the gas storage reservoir will not be damaged and sand will not be produced. The reasonable production pressure difference can be determined by the formation strength method, that is, the mud content and reservoir water content of the gas well are obtained through well logging data, and the formula is used to determine the reasonable production pressure difference. Obtain the shear strength τ of the rock in the gas well, where V sh is the mud content, S W is the water content of the reservoir. When the production pressure difference is 1.7 times the shear strength, the rock is destroyed and sand is produced. Therefore, the calculated shear strength τ is multiplied by 1.7 to obtain a reasonable production pressure difference. The development data is the data obtained in the early development process of the gas storage, including various data in the process of developing crude oil and natural gas. In order to improve the accuracy of determining the injection and production capacity of gas wells in gas-cap reservoir-type gas storage, this embodiment adopts the phase permeability design method, while considering the influence of oil phase permeability and gas phase permeability on the injection and production capacity. The development data can be various basic data such as production, pressure, fluid, and formation of oil and gas phases obtained during the development period. After obtaining the reasonable production pressure difference and development data, step S12 is entered.

[0061] S12. Obtain the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jurg-Pierre formula, wherein the first target data is the data required for calculating the oil phase permeability using the Jurg-Pierre formula.

[0062] Specifically, the oil phase permeability can be calculated by using the Jörg-Becker equation Solve, where q o is the daily oil production, K ro is the oil phase permeability, h is the effective reservoir thickness, μ o is the viscosity of crude oil, B o is the crude oil volume coefficient, r e is the reservoir drainage radius, r w is the wellbore radius, S is the skin coefficient, Δp is the reasonable production pressure difference, and after the oil phase permeability is calculated, step S13 is entered.

[0063] S13. Obtain the gas phase permeability of the gas storage reservoir according to the second target data of the development data and the binomial gas well productivity equation, wherein the second target data is the data required to calculate the gas phase permeability using the binomial gas well productivity equation.

[0064] Specifically, the calculation of gas permeability can be used to develop the binomial gas well productivity equation for natural gas Solve, where q sc is the daily gas production, K is the gas permeability, h is the effective reservoir thickness, p e is the formation pressure, p wf is the bottom hole flowing pressure, is the formation temperature, p r is the original formation pressure (or original formation static pressure), q g is the gas wellhead production, is the natural gas viscosity, Z is the natural gas deviation factor, D is the non-Darcy flow coefficient, S is the skin coefficient, and after the gas phase permeability is calculated, step S14 is entered.

[0065] S14. Determine the gas production capacity of the gas wells of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability.

[0066] Specifically, the reasonable production pressure difference represents the pressure difference between the injection pressure and the outlet pressure during the operation of the gas storage reservoir; the oil phase permeability and gas phase permeability represent the permeability of the oil phase and the gas phase in the gas storage reservoir, respectively. There is a corresponding relationship between the reasonable production pressure difference, oil phase permeability, gas phase permeability and the gas production capacity of the gas well, so a calibration experiment can be conducted based on this to obtain a corresponding relationship table, and the gas production capacity of the gas well can be obtained by querying the corresponding relationship table based on the current reasonable production pressure difference, oil phase permeability, and gas phase permeability.

[0067] In a specific embodiment, the gas production capacity of the gas well of the gas storage reservoir is determined according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, including:

[0068] The first step is to obtain the laminar coefficient and turbulent coefficient based on the oil phase permeability, gas phase permeability and binomial coefficient equation. Since the oil phase permeability characterizes the permeability of the oil phase in the gas storage reservoir, and the gas phase permeability characterizes the permeability of the gas phase in the gas storage reservoir, the effective permeability can be obtained based on the sum of the permeabilities of the oil phase permeability and the gas phase permeability. Then, the binomial coefficient equation can be solved based on the effective permeability to obtain the gas well production capacity, which includes:

[0069] According to the formula The laminar flow coefficient A is obtained;

[0070] According to the formula The turbulence coefficient B is obtained, where is the viscosity of natural gas, is the natural gas deviation factor, is the formation temperature, h is the effective reservoir thickness, K is the effective permeability, t is the penetration time, r w is the converted radius of the gas well, φ is the porosity of the gas layer, C t is the comprehensive compression coefficient of the formation, D is the non-Darcy flow coefficient, p sc is the gas pressure under standard conditions, T sc is the gas temperature under standard conditions, S a is the apparent skin factor.

[0071] In the second step, the binomial gas well production capacity equation is solved according to the reasonable production pressure difference, laminar coefficient, turbulence coefficient and the original formation pressure of the gas storage reservoir to obtain the gas well production and determine the gas production capacity of the gas well.

[0072] The binomial gas well productivity equation is p r 2 -p wf 2 =Aq g +Bq g 2 , where p r is the original formation pressure, pwf is the bottom flow pressure, A is the laminar coefficient, and B is the turbulent coefficient. Based on this, the gas well production (or gas well wellhead production) q g , to characterize the gas production capacity of the gas well.

[0073] In actual application, since the oil and gas permeability inside the gas storage is in a dynamic state of change during operation, if the gas well gas production capacity is designed as a fixed value, the gas well gas production capacity of the gas storage may be designed to be too small. Based on this, in a specific implementation, before determining the gas well gas production capacity of the gas storage based on the reasonable production pressure difference, oil phase permeability and gas phase permeability, the method also includes:

[0074] Obtain the permeability-yield relationship between the effective permeability and the yield index of the gas storage reservoir; the effective permeability can be the sum of the oil phase permeability and the gas phase permeability. Since the yield index per meter of the unit production pressure difference between the oil phase and the gas phase is proportional to the effective permeability, the data obtained in the early development stage of the gas storage reservoir can be used for regression line to obtain the relationship between the effective permeability and the yield index, that is, the permeability-yield relationship. The formula can be obtained by the deformation of the Jubilee formula:

[0075]

[0076] The formula can be obtained by transforming the gas well productivity formula:

[0077] The above formula can be used to derive the permeability-production relationship of the gas storage reservoir.

[0078] The injection-production phase permeability test is carried out on the actual drilled core of the gas storage reservoir in different cycles. The injection-production phase permeability test simulates the operation status of the gas storage reservoir in the laboratory. In order to determine the permeability of the internal formation of the gas storage reservoir, the core is drilled for different cycles of gas injection and gas production. The phase permeability curve is generated based on the experimental data fitting, that is, the phase permeability curve of multiple rounds of two-phase continuous drive. Please refer to Figure 2 In different operation cycles, the phase permeability of the formation will change dynamically. The curves krg1-krg10 in the figure are the change curves of the gas phase. As the oil saturation increases, the relative permeability also increases, but there are certain differences in the increase amplitude in different cycles; the curves kro1-kro10 in the figure are the change curves of the oil phase. As the oil saturation increases, the relative permeability decreases, but there are certain differences in the decrease amplitude in different cycles. Based on this, the changing characteristics of the phase permeability can be obtained.

[0079] Since the permeability-production relationship characterizes the corresponding relationship between effective permeability and production index; the phase permeability curve characterizes the permeability of the oil phase in different operation cycles, and the permeability of the gas phase in different operation cycles, the gas phase production index and oil phase production index of each gas saturation in each operation cycle can be obtained by comparing the two. According to the reasonable production pressure difference, gas phase production index and oil phase production index, the maximum gas production of the gas storage in each operation cycle and the corresponding formation pressure is obtained; the maximum gas production is determined as the gas production capacity of the gas well to improve the operation efficiency of the gas storage.

[0080] The formation strength method is a method for calculating the shear strength of rocks, predicting and controlling the sand production of reservoirs, and providing a basis for the design of gas well injection and production capacity; the phase permeability design method is a method for comprehensively designing the gas production capacity of gas wells by using production analysis and indoor experiments, taking into account the influence of the effective permeability of the oil phase on the gas phase. During operation, the flow characteristics inside the gas storage reservoir vary greatly. There are limitations in determining the gas production capacity using only the formation strength method and the phase permeability design method, which may result in insufficient accuracy in determining the gas production capacity. Based on this, in a specific embodiment, after determining the gas well production capacity of the gas storage reservoir based on reasonable production pressure difference, oil phase permeability and gas phase permeability, the method also includes:

[0081] Obtain a graph of the gas well IPR inflow curve and the wellbore flow curve. Figure 3 , Figure 3 It is a schematic diagram of the curve superposition diagram. Curve S1 is the IPR inflow curve of the gas well. The IPR inflow curve of the gas well represents the changing relationship between the gas production and the bottom hole flow pressure. The multiple arc curves in the figure represent the gas production corresponding to different bottom hole flow pressures. Curve S2 is the wellbore flow curve (or erosion flow curve), and curve S3 is the sand flow curve. The relationship between the bottom hole pressure and the gas production can be obtained through the curve superposition diagram.

[0082] Since the reasonable production pressure difference is the pressure difference that ensures that the formation is not damaged during the generation of the gas storage, in order to ensure the normal operation of the gas storage, the gas production capacity of the gas well using the node analysis can be determined in the curve superposition diagram based on the reasonable production pressure difference; the node analysis method is a method of taking the flow of the gas flow from the starting point to the end point as a research object, comprehensively analyzing the pressure loss of the entire system, and designing the gas production capacity of the gas well. The node analysis method is a method of taking the bottom hole flow as a coordination point, superimposing the inflow of the formation, the outflow of the wellbore, the liquid carrying, the erosion and other curves, and calculating the gas production capacity of the gas well under the condition of high-speed unstable seepage. Therefore, based on the curve superposition diagram, the gas production capacity of the gas well can be more accurately determined under the boundary conditions of the bottom hole flow pressure and the reasonable production pressure difference. Then, the gas production capacity of the gas well of the gas storage is updated according to the gas well production capacity of the application node analysis. When updating, the weights of various methods can be comprehensively judged by fuzzy mathematics to comprehensively design the gas production capacity of the gas well. For example, the first weight θ1 and the second weight θ2 are set, and according to the formula qg1 ×θ1+q g2 ×θ2=q g , determine the updated gas well production capacity, q g1 is the gas production capacity of the gas well calculated initially, q g2 The gas production capacity of the gas well determined in the curve superposition diagram; after the gas production capacity of the gas well is determined, step S15 is entered.

[0083] S15. Test-injecting nitrogen into the gas storage reservoir according to the reasonable production pressure difference to determine the gas injection capacity of the gas wells of the gas storage reservoir.

[0084] Specifically, the nitrogen test injection method is a method for designing the gas injection capacity of a gas well by calibrating the flow rates of nitrogen and natural gas to establish a modified binomial gas well production capacity equation. The actual gas injection flow rate of the gas storage reservoir under the formation structure can be determined through nitrogen test injection. To ensure that the formation structure does not change under this injection flow rate, a reasonable production pressure difference is used as a limiting condition to ensure the normal operation of the gas storage reservoir.

[0085] See also Figure 4 , Figure 4 This is a diagram of the implementation steps of the nitrogen test injection method. In the early stage of the nitrogen test injection, a shut-in pressure drop test needs to be carried out to obtain formation parameters such as formation temperature, gas leakage radius, skin coefficient, effective permeability, turbulence coefficient, etc. The steps to determine the gas injection capacity of the gas well include:

[0086] The first step is to construct an air suction indication curve; wherein the air suction indication curve is a curve showing the change of nitrogen injection volume following the bottom hole flow pressure, and the bottom hole flow pressure corresponding to different injection volumes is obtained through the air suction indication curve. The air suction indication curve can be constructed by fitting the data of nitrogen injection flow rate and bottom hole flow pressure obtained after nitrogen test injection.

[0087] The second step is to solve the binomial gas well productivity equation of nitrogen injection according to the suction indication curve to obtain the test injection laminar coefficient and test injection turbulence coefficient. The binomial gas well productivity equation of nitrogen can be obtained by fitting the data obtained during the nitrogen injection process. The gas well productivity equation is:

[0088]

[0089] Where K is the effective permeability of the formation, h is the effective thickness of the formation, is the reference viscosity of the gas layer under average conditions, p sc The pressure of the gas under standard conditions, T sc is the temperature of the gas under standard conditions, φ is the porosity of the gas layer, C t is the comprehensive compression coefficient of the formation, t is the time, S a is the apparent skin coefficient, r w is the converted radius of the gas well.

[0090] Set the laminar coefficient of the test injection to A1 and the turbulent coefficient of the test injection to B1.

[0091]

[0092]

[0093] Then the production capacity equation of injected nitrogen is P wf 2 -P r 2 =A1q g +B1q g 2 .

[0094] Based on the data obtained during the nitrogen test injection process, the deviations of the laminar flow coefficient and turbulence coefficient of the injected nitrogen from the theoretical values ​​can be obtained, and the laminar flow coefficient and turbulence coefficient of the natural gas can be corrected based on the obtained deviations.

[0095] In a specific embodiment, the laminar flow coefficient of natural gas is corrected according to the test injection laminar flow coefficient, and the turbulence coefficient of natural gas is corrected according to the test injection turbulence coefficient, including:

[0096] According to the formula Obtain the corrected laminar flow coefficient A2;

[0097] According to the formula The corrected turbulence coefficient B2 is obtained; where A1 is the test laminar coefficient, B1 is the test turbulence coefficient, μ g1 is the nitrogen flow rate, μ g2 is the natural gas fluidity, Z1 is the nitrogen deviation factor, Z2 is the natural gas deviation factor, K1 is the nitrogen effective permeability, and K2 is the natural gas effective permeability. The above formula can be used to correct the laminar coefficient and turbulent coefficient of natural gas.

[0098] In the third step, after the laminar coefficient and turbulent coefficient of natural gas are corrected, the binomial gas well capacity equation for injected natural gas is solved according to the reasonable production pressure difference, laminar coefficient and turbulent coefficient to obtain the gas well injection capacity. The capacity equation for injected natural gas is P wf 2 -P r 2 =A2q g +B2q g 2 , bottom hole flowing pressure p wf , original formation pressure p r , laminar coefficient A2 and turbulent coefficient B2 are all known, and q g The gas injection capacity of the gas well can be obtained.

[0099] It should be noted that the gas well production capacity of the gas storage reservoir can also be obtained based on the nitrogen test injection method. The gas well production capacity obtained by the phase permeability design method and the gas well production capacity obtained by the node analysis method can also be used to determine the gas well production capacity of the gas storage reservoir through weighted calculation.

[0100] See also Figure 5 , Figure 5 The following is a diagram of the implementation steps of this embodiment. In the following embodiment of the present invention, three methods are combined to determine the gas production capacity of the gas well. Taking the nitrogen test injection method to obtain the gas injection capacity of the gas well as an example, the method for determining the injection and production capacity of the gas storage reservoir is specifically described. The gas cap reservoir type gas storage reservoir is a gas storage reservoir rebuilt from the gas-term oil ring edge bottom water oil and gas reservoir. The reservoir is buried at a depth of 2200-2550m, with a thickness of up to 150-220m, a porosity of 17.3%, an air permeability of 224mD, and a reported oil geological reserve of 848.25×10 8 t, geological reserves of dissolved gas: 19.91×10 8 m 3 , natural gas geological reserves of 51.09×10 8 m 3 , condensate oil geological reserves 70.29×10 8 t, the formation pressure before reservoir construction was 5.0MPa, and the original formation pressure was 24.27MPa. The development was carried out based on the principles of protecting gas cap energy, avoiding perforating gas layers and water layers, and optimizing partial oil layer production. The injection and production capacity of gas wells was determined through formation strength method, actual production capacity analysis method, node analysis method, and nitrogen test injection method.

[0101] Using the formation strength method, when the production pressure difference is 1.7 times the rock shear strength, the rock begins to break and produce sand. Through theoretical calculations and reference to the sand production experiment of the Sebei gas field, it is determined that the critical sand production pressure difference of the gas cap reservoir type gas storage is 3.5MPa.

[0102] By applying the phase permeability design method, the relationship between effective permeability and production index is obtained based on the basic data of the development stage; the relative permeability corresponding to each oil saturation is read based on the phase permeability curves of different cycles tested in the laboratory; the maximum gas production at the wellhead can be obtained by matching the permeability with the relationship.

[0103] Through the phase permeability design method, when the formation pressure in the first cycle is 25MPa, the production pressure difference is 3.5MPa, the gas phase relative permeability is 70%, and the oil phase relative permeability is 4%, the gas well gas production capacity is 97×10 4 m 3 .

[0104] Applying the node analysis method, the IPR inflow curve of the gas well and the wellbore flow capacity curve are calculated. Please continue to refer to Figure 3Point M in the figure is the gas production capacity of the gas well. The gas production capacity of the gas well is determined to be 95×10 4 m 3 .

[0105] The nitrogen test injection method was used to determine the gas absorption capacity of the reservoir and obtain relevant parameters to provide a basis for the design of the injection and production capacity of the gas well. After the nitrogen test injection, according to the test injection results, the gas injection capacity of the gas well was determined to be 94×10 4 m 3 The gas production capacity of the gas well determined by nitrogen injection test method is 96×10 4 m 3 The gas production capacity of the three gas wells was calculated by weighted average and the gas production capacity of the gas well was 96×10 4 m 3 .

[0106] To further verify the accuracy of the design results of the gas well injection and production capacity, the actual production data of the gas storage facility was collected after it was put into operation. Please refer to Table 1.

[0107] Table 1:

[0108]

[0109]

[0110] By monitoring the daily oil production, daily gas production, and formation pressure during the production process of the injection and production wells, the injection and production capacity of the gas wells in the actual production process is determined, and the design result of the gas well injection and production capacity is basically consistent with the actual production data. This further verifies the reliability and practicality of the gas well injection and production capacity design method for the gas cap reservoir type gas storage. Through the determination method of the embodiment of the present invention, the number of deployed injection and production wells of the gas storage can be optimized, and the injection and production capacity of the gas wells can be made to fit the actual situation to the greatest extent, so as to ensure the operation efficiency of the gas storage.

[0111] Based on the same inventive concept as the determination method, the embodiment of the present invention also provides a device for determining the injection and production capacity of a gas storage reservoir, which is applied to determine the injection and production capacity of a gas well in a gas cap reservoir type gas storage reservoir. Figure 6 , Figure 6 is a schematic diagram of the structure of the device, the device comprising:

[0112] The first acquisition module 601 is used to acquire the reasonable production pressure difference of the gas storage and the development data during the reservoir development period;

[0113] A first obtaining module 602 is used to obtain the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jubby formula, wherein the first target data is the data required to calculate the oil phase permeability using the Jubby formula;

[0114] A second obtaining module 603 is used to obtain the gas phase permeability of the gas storage reservoir according to the second target data of the development data and the binomial gas well productivity equation, wherein the second target data is the data required to calculate the gas phase permeability using the binomial gas well productivity equation;

[0115] A first determination module 604 is used to determine the gas production capacity of the gas well of the gas storage according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability;

[0116] The second determination module 605 is used to perform nitrogen test injection on the gas storage according to the reasonable production pressure difference to determine the gas injection capacity of the gas well of the gas storage.

[0117] In an optional embodiment, the first determining module includes:

[0118] A first obtaining submodule is used to obtain a laminar coefficient and a turbulent coefficient according to the oil phase permeability, the gas phase permeability and the binomial coefficient equation;

[0119] The second acquisition submodule is used to solve the binomial gas well production capacity equation according to the reasonable production pressure difference, the laminar flow coefficient, the turbulence coefficient and the original formation pressure of the gas storage reservoir to obtain the gas well production to determine the gas production capacity of the gas well.

[0120] In an optional embodiment, the first obtaining submodule includes:

[0121] A first obtaining unit, configured to obtain an effective permeability according to the sum of the permeability of the oil phase permeability and the gas phase permeability;

[0122] The second acquisition unit is used to obtain the Obtaining the laminar flow coefficient A;

[0123] The third obtaining unit is used to obtain the The turbulence coefficient B is obtained, where is the viscosity of natural gas, is the natural gas deviation factor, is the formation temperature, h is the effective reservoir thickness, K is the effective permeability, t is the penetration time, r w is the converted radius of the gas well, φ is the porosity of the gas layer, C t is the comprehensive compression coefficient of the formation, D is the non-Darcy flow coefficient, p sc is the gas pressure under standard conditions, T sc is the gas temperature under standard conditions, S a is the apparent skin factor.

[0124] In an optional embodiment, the device further includes:

[0125] A second acquisition module is used to obtain the permeability-yield relationship between the effective permeability and the yield index of the gas storage reservoir;

[0126] The third acquisition module is used to perform injection-production phase permeability tests of different periods on the actual drilled cores of the gas storage to obtain a phase permeability curve;

[0127] A fourth acquisition module is used to obtain a gas phase production index and an oil phase production index at each gas saturation in each operation cycle according to the permeability-production relationship and the phase permeability curve;

[0128] A fifth obtaining module, used for obtaining the maximum gas production of the gas storage in a corresponding operation cycle and corresponding formation pressure according to the reasonable production pressure difference, the gas phase production index and the oil phase production index;

[0129] The third determination module is used to determine the maximum gas production volume as the gas production capacity of the gas well.

[0130] In an optional embodiment, the device further includes:

[0131] The third acquisition module is used to obtain a curve superposition diagram of the gas well IPR inflow curve and the wellbore flow curve;

[0132] A fourth determination module is used to determine the gas production capacity of the gas well using the application node analysis in the curve superposition diagram according to the reasonable production pressure difference;

[0133] The updating module is used to update the gas production capacity of the gas well of the gas storage according to the gas production capacity of the gas well analyzed by the application node.

[0134] In an optional embodiment, the second determining module includes:

[0135] A construction submodule is used to construct a gas suction indication curve; wherein the gas suction indication curve is a curve of nitrogen injection volume following the change of bottom hole flow pressure;

[0136] The third acquisition submodule is used to solve the binomial gas well productivity equation of nitrogen injection according to the gas suction indication curve to obtain the test injection laminar coefficient and the test injection turbulence coefficient;

[0137] A correction submodule, used to correct the laminar flow coefficient of the natural gas according to the test injection laminar flow coefficient, and to correct the turbulence coefficient of the natural gas according to the test injection turbulence coefficient;

[0138] The fourth obtaining submodule is used to solve the binomial gas well production capacity equation for injecting natural gas according to the reasonable production pressure difference, the laminar flow coefficient and the turbulence coefficient to obtain the gas injection capacity of the gas well.

[0139] In an optional embodiment, the correction submodule includes:

[0140] The fourth obtaining unit is used to obtain Obtain the corrected laminar flow coefficient A2;

[0141] The fifth obtaining unit is used to obtain The corrected turbulence coefficient B2 is obtained; where A1 is the test laminar coefficient, B1 is the test turbulence coefficient, μ g1 is the nitrogen flow rate, μ g2 is the natural gas fluidity, Z1 is the nitrogen deviation factor, Z2 is the natural gas deviation factor, K1 is the nitrogen effective permeability, and K2 is the natural gas effective permeability.

[0142] Based on the same inventive concept as the determination method, an embodiment of the present invention also provides an electronic device, including a processor and a memory, wherein the memory is coupled to the processor, and the memory stores instructions, which, when executed by the processor, enable the electronic device to perform the steps of any one of the methods described in the determination method.

[0143] Based on the same inventive concept as the determination method, an embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the steps of any one of the methods described in the determination method are implemented.

[0144] The technical solution provided in the embodiments of the present invention has at least the following technical effects or advantages:

[0145] By obtaining the reasonable production pressure difference of the gas storage reservoir and the development data during the reservoir development period, the Joubert formula is solved according to the first target data of the development data to obtain the oil phase permeability, and the binomial gas well production capacity equation is solved according to the second target data of the development data to obtain the gas phase permeability. The gas well gas production capacity is determined according to the reasonable production pressure difference, oil phase permeability and gas phase permeability. The gas storage reservoir is subjected to nitrogen test injection to determine the gas well gas injection capacity according to the reasonable production pressure difference. Since the influence of the permeability of the oil phase and the gas phase is considered when determining the gas well gas production capacity, the nitrogen test injection can best fit the actual situation inside the gas storage reservoir when determining the gas well gas injection capacity, making the determination of the gas well injection and production capacity applied to the gas cap reservoir type gas storage reservoir more scientific and guiding, thereby improving the accuracy of the determination of the gas storage reservoir injection and production capacity.

[0146] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0147] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (modules, systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded computer, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0148] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0149] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0150] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0151] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for determining the injection and production capacity of a gas storage facility, characterized in that: The method for determining the injection and production capacity of a gas well of a gas cap reservoir type gas storage facility comprises: Obtain the reasonable production pressure difference of the gas storage and the development data during the reservoir development period; Obtaining the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jubby formula, wherein the first target data is the data required for calculating the oil phase permeability using the Jubby formula; According to the second target data of the development data and the binomial gas well productivity equation, the gas phase permeability of the gas storage reservoir is obtained, wherein the second target data is the data required for calculating the gas phase permeability using the binomial gas well productivity equation; Determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability; The gas storage reservoir is tested for nitrogen injection according to the reasonable production pressure difference to determine the gas injection capacity of the gas wells of the gas storage reservoir.

2. The method for determining the injection and production capacity of a gas storage facility according to claim 1, characterized in that: The determining of the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability comprises: According to the oil phase permeability, the gas phase permeability and the binomial coefficient equation, a laminar coefficient and a turbulent coefficient are obtained; The binomial gas well production capacity equation is solved according to the reasonable production pressure difference, the laminar flow coefficient, the turbulence coefficient and the original formation pressure of the gas storage reservoir to obtain the gas well production to determine the gas production capacity of the gas well.

3. The method for determining the injection and production capacity of a gas storage facility according to claim 2, characterized in that: The step of obtaining the laminar flow coefficient and the turbulent flow coefficient according to the oil phase permeability, the gas phase permeability and the binomial coefficient equation comprises: Obtaining effective permeability according to the sum of the permeability of the oil phase permeability and the gas phase permeability; According to the formula Obtaining the laminar flow coefficient A; According to the formula The turbulence coefficient B is obtained, where is the viscosity of natural gas, is the natural gas deviation factor, is the formation temperature, h is the effective reservoir thickness, K is the effective permeability, t is the penetration time, r w is the converted radius of the gas well, φ is the porosity of the gas layer, C t is the comprehensive compression coefficient of the formation, D is the non-Darcy flow coefficient, p sc is the gas pressure under standard conditions, T sc is the gas temperature under standard conditions, S a is the apparent skin factor.

4. The method for determining the injection and production capacity of a gas storage facility according to claim 1, characterized in that: Before determining the gas production capacity of the gas well of the gas storage according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, the method further comprises: Obtaining a permeability-yield relationship between an effective permeability and a yield index of the gas storage reservoir; Performing injection-production phase permeability tests at different cycles on the actual drilled cores of the gas storage to obtain phase permeability curves; According to the permeability-production relationship and the phase permeability curve, a gas phase production index and an oil phase production index at each gas saturation in each operation cycle are obtained; According to the reasonable production pressure difference, the gas phase production index and the oil phase production index, the maximum gas production of the gas storage in the corresponding operation cycle and the corresponding formation pressure is obtained; The maximum gas production volume is determined as the gas production capacity of the gas well.

5. The method for determining the injection and production capacity of a gas storage facility according to claim 1, characterized in that: After determining the gas production capacity of the gas well of the gas storage reservoir according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability, the method further comprises: Obtain a curve superposition diagram of the gas well IPR inflow curve and the wellbore flow curve; Determine the gas production capacity of the gas well using the node analysis in the curve superposition diagram according to the reasonable production pressure difference; The gas well gas production capacity of the gas storage is updated according to the gas well gas production capacity analyzed by the application node.

6. The method for determining the injection and production capacity of a gas storage facility according to claim 1, characterized in that: The step of testing nitrogen injection into the gas storage according to the reasonable production pressure difference to determine the gas injection capacity of the gas well of the gas storage comprises: Constructing a gas suction indication curve; wherein the gas suction indication curve is a curve showing the change of nitrogen injection volume following the bottom hole flow pressure; Solving the binomial gas well productivity equation for nitrogen injection according to the gas suction indication curve to obtain the test injection laminar coefficient and the test injection turbulence coefficient; Correcting the laminar flow coefficient of natural gas according to the test injection laminar flow coefficient, and correcting the turbulence coefficient of natural gas according to the test injection turbulence coefficient; The binomial gas well production capacity equation for injecting natural gas is solved according to the reasonable production pressure difference, the laminar flow coefficient and the turbulence coefficient to obtain the gas injection capacity of the gas well.

7. The method for determining the injection and production capacity of a gas storage facility according to claim 6, characterized in that: The step of correcting the laminar flow coefficient of the natural gas according to the test injection laminar flow coefficient and the step of correcting the turbulence coefficient of the natural gas according to the test injection turbulence coefficient comprises: According to the formula Obtain the corrected laminar flow coefficient A2; According to the formula The corrected turbulence coefficient B2 is obtained; where A1 is the test laminar coefficient, B1 is the test turbulence coefficient, μ g1 is the nitrogen flow rate, μ g2 is the natural gas fluidity, Z1 is the nitrogen deviation factor, Z2 is the natural gas deviation factor, K1 is the nitrogen effective permeability, and K2 is the natural gas effective permeability.

8. A device for determining the injection and production capacity of a gas storage reservoir, characterized in that: The device is applied to determine the injection and production capacity of a gas well of a gas cap reservoir type gas storage, and comprises: The first acquisition module is used to obtain the reasonable production pressure difference of the gas storage and the development data during the reservoir development period; A first obtaining module is used to obtain the oil phase permeability of the gas storage reservoir according to the first target data of the development data and the Jubby formula, wherein the first target data is the data required to calculate the oil phase permeability using the Jubby formula; A second obtaining module is used to obtain the gas phase permeability of the gas storage reservoir according to the second target data of the development data and the binomial gas well productivity equation, wherein the second target data is the data required to calculate the gas phase permeability using the binomial gas well productivity equation; A first determination module is used to determine the gas production capacity of the gas well of the gas storage according to the reasonable production pressure difference, the oil phase permeability and the gas phase permeability; The second determination module is used to perform nitrogen test injection on the gas storage according to the reasonable production pressure difference to determine the gas injection capacity of the gas wells of the gas storage.

9. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein the memory is coupled to the processor and stores instructions, and when the instructions are executed by the processor, the electronic device executes the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 7 are implemented.

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