Gas storage stock evaluation method and device, storage medium and equipment

Abstract

The invention discloses a gas storage stock evaluation method and device, a storage medium and equipment, and the method can comprise the steps: constructing an injection-production well partition flow model in a gas storage according to the strong injection-production characteristic parameters of the gas storage, and building a single-well formation pressure model based on the seepage field characteristics and the injection-production well partition flow model; based on the single-well formation pressure model and the single-well formation pressure calculation parameters, the formation pressure of a single well is determined, and then the average formation pressure of the gas storage is determined; determining a gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injection and production gas of the gas storage and the reservoir temperature of the gas storage; the inventory of the gas storage is determined on the basis of the gas compression factor and the average formation pressure of the gas storage, the error chart is constructed in combination with measured data, and compared with a traditional numerical simulation method, the method is easy and convenient to operate, and the inventory evaluation calculation time is shortened to the maximum extent under the condition that the calculation result precision is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas development, and in particular to a method, device, storage medium and equipment for evaluating the inventory of a gas storage facility. Background Art

[0002] Natural gas has the advantages of high calorific value, low environmental pollution and high economic benefits. It plays an important role in improving energy structure, alleviating the contradiction between energy supply and demand, and improving environmental quality, and has been widely used worldwide. There is an inherent contradiction between natural gas production and consumption, and underground gas storage can optimize the gas supply system to meet the needs of natural gas peak regulation, accident emergency and strategic reserve. When there is a peak in gas consumption or special circumstances, gas can be extracted from the gas storage to increase the gas supply capacity and ensure continuous supply of natural gas. By adjusting the injection and extraction time, the contradiction of unbalanced gas consumption can be solved, so that natural gas resources can be reasonably used to obtain the best economic benefits.

[0003] A series of methods for calculating the capacity of a gas storage reservoir are disclosed in the prior art. For example, CN108625823A discloses a method for determining the capacity of a gas storage reservoir, which includes the following steps: establishing a formation pressure model according to the real-time radius of the gas layer in the gas storage reservoir; establishing a bottom hole flow pressure model according to the effective permeability of the gas storage reservoir and the gas layer skin coefficient; establishing a wellhead oil pressure model and a gas injection model of the gas storage reservoir according to the formation pressure model and the bottom hole flow pressure model; and determining the capacity of the gas storage reservoir according to the wellhead oil pressure model and the gas injection model. CN114818514A discloses a method and processor for determining the storage capacity of a gas storage reservoir, comprising: establishing a three-dimensional geological model based on acquired fault data, structural layer data, layer parameter data and well trajectory data; selecting the permeability, porosity and relative permeability curves in the model as time-varying parameters in oil reservoir numerical simulation; transforming the black oil model based on the time-varying phenomenon of reservoir physical properties to form a new mathematical model, the new mathematical model is used to reflect the changes in permeability and relative permeability curves with surface flux, and the continuity equation in the new mathematical model changes; reading the first effective pore volume after multi-cycle historical fitting of the three-dimensional geological model, and calculating the second effective pore volume contributed by each gas storage reservoir fluid area to the dynamic reserves of the gas reservoir; determining the storage capacity of the gas storage reservoir based on the second effective pore volume and the natural gas compression factor. Summary of the invention

[0004] In order to effectively solve the problem of accurate calculation and evaluation of gas storage inventory, and thereby provide accurate support for gas storage peak load regulation to enrich technical routes and increase selection space, a gas storage inventory evaluation method, device, storage medium and equipment are provided in the embodiments of the present invention.

[0005] In a first aspect, an embodiment of the present invention provides a method for evaluating gas storage inventory, which may include:

[0006] According to the strong injection and strong production characteristic parameters of the gas storage, a partitioned flow model of the injection and production wells in the gas storage is constructed, so as to establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells;

[0007] Determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method;

[0008] Determining an average formation pressure of the gas storage based on the formation pressures of all single wells included in the gas storage;

[0009] Determining the gas compressibility factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage;

[0010] The inventory of the gas storage reservoir is determined based on the gas compressibility factor and the average formation pressure of the gas storage reservoir, so as to construct a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart in combination with measured data.

[0011] Optionally, the method may further include:

[0012] Based on the geological characteristic parameters of the gas storage reservoir, a gas storage reservoir inventory calculation correction model is pre-built;

[0013] Performing quantitative error analysis on the inventory calculation correction model to construct an inventory relative error calculation model for the gas storage facility;

[0014] Based on the gas compression factor, average formation pressure, inventory and measured gas compression factor, average formation pressure and inventory of the gas storage reservoir, and the inventory relative error calculation model, the relative error of the unbalanced state of the gas storage reservoir is determined.

[0015] Optionally, the method may further include: constructing a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map based on a relative error of the unbalanced state of the gas storage reservoir.

[0016] Optionally, determining the relative error of the unbalanced state of the gas storage may include:

[0017] The relative error of the inventory is determined based on the gas compression factor, average formation pressure, and inventory of the gas storage reservoir and the measured gas compression factor, average formation pressure, and inventory, so as to correct the inventory of each injection and production cycle of the gas storage reservoir and establish a curve of inventory error versus pressure error.

[0018] Optionally, the inventory calculation correction model is:

[0019]

[0020] Among them, I is the inventory, m 3 ;

[0021] ΔQ is the gas production or injection volume, m 3 ;

[0022] p is the average formation pressure of the gas storage, MPa;

[0023] Z is the gas compressibility factor, dimensionless;

[0024] T is the reservoir temperature, K;

[0025] ε is the relative error of the unbalanced state of the gas storage;

[0026] Wherein, subscripts 1 and 2 represent the end of gas injection and the end of gas production, respectively.

[0027] Optionally, determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method may include:

[0028] Collecting gas component content of injected and produced gas, reservoir temperature, production data and pressure recovery data or pressure drop data during the operation cycle of the gas storage reservoir;

[0029] Based on the unstable well test analysis method, double logarithmic fitting, semi-logarithmic fitting and production history data fitting are performed on the test well to obtain the single well formation pressure calculation parameters of the test well, wherein the single well formation pressure calculation parameters include: wellbore storage coefficient, skin coefficient, permeability, mobility ratio and composite radius;

[0030] The single well formation pressure calculation parameters are brought into the single well formation pressure model to determine the single well formation pressure.

[0031] In a second aspect, an embodiment of the present invention provides a method for determining the inventory of a gas storage reservoir, which may include:

[0032] Determine the effective inventory of the gas storage according to the measured average formation pressure, gas compressibility factor and injection and production volume of the gas storage, as well as the pressure drop-inventory error chart and / or the pseudo-pressure error-inventory error chart;

[0033] The pressure drop-inventory error chart and / or the pseudo-pressure error-inventory error chart are obtained in advance according to the gas storage inventory evaluation method described in the first aspect.

[0034] In a third aspect, an embodiment of the present invention provides a gas storage inventory evaluation device, which may include:

[0035] A single well formation pressure model building module is used to build a partitioned flow model of the injection and production wells in the gas storage according to the strong injection and strong production characteristic parameters of the gas storage, so as to establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells;

[0036] A single well formation pressure determination module, used to determine the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method;

[0037] A gas storage reservoir average formation pressure determination module, used to determine the average formation pressure of the gas storage reservoir based on the formation pressures of all single wells included in the gas storage reservoir;

[0038] A gas compression factor determination module, used to determine the gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage;

[0039] An inventory determination module, configured to determine the inventory of the gas storage based on the gas compression factor and the average formation pressure of the gas storage;

[0040] A map construction module is used to construct a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map in combination with measured data.

[0041] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the gas storage inventory evaluation method as described in the first aspect.

[0042] In a fifth aspect, an embodiment of the present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the gas storage reservoir inventory evaluation method as described in the first aspect is implemented.

[0043] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0044] The embodiment of the present invention provides a method, device, storage medium and equipment for evaluating the inventory of a gas storage reservoir. The method aims to solve the problem that the average formation pressure of the gas storage reservoir is difficult to accurately obtain due to the short injection-production balance time, the large number of injection-production wells and the serious interference between wells during the operation of the gas storage reservoir. First, a mathematical model for calculating the average formation pressure of a single well is established based on the seepage mechanics theory, and then the influence of the interference between wells is solved by the well control volume weighting method, and the average formation pressure of the gas storage reservoir is obtained; finally, the errors of the pressure and compression factor are corrected based on the error theory analysis method, and the mathematical model for inventory calculation based on the error theory is obtained, and an error theory chart is established. Compared with the traditional numerical simulation method, this method is simple in calculation and easy to operate. Under the condition of ensuring the accuracy of the calculation results, the time for inventory evaluation calculation is minimized.

[0045] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0046] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0048] Figure 1 A flow chart of a gas storage inventory evaluation method provided in an embodiment of the present invention;

[0049] Figure 2 A flowchart of a detailed gas storage inventory evaluation method provided in an embodiment of the present invention;

[0050] Figure 3 A simplified schematic diagram of vertical well-to-well interference provided in an embodiment of the present invention;

[0051] Figure 4 A simplified schematic diagram of the interference between vertical wells and horizontal wells provided in an embodiment of the present invention;

[0052] Figure 5 A pressure drop and inventory error chart provided in an embodiment of the present invention;

[0053] Figure 6 A pseudo-pressure error and inventory error chart provided in an embodiment of the present invention;

[0054] Figure 7 It is a schematic diagram of the structure of a gas storage inventory evaluation device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0056] The above-mentioned prior art documents are all methods for calculating the capacity of gas storage reservoirs, which are all applied in the design stage of gas storage reservoirs, but cannot be applied to the operation process of gas storage reservoirs after the design is completed. Therefore, they fail to effectively solve the problem of accurate calculation and evaluation of gas storage inventories, and thus cannot provide accurate support for gas storage peak regulation. At the same time, the inventors found that, on the one hand, the inventory of underground gas storage reservoirs is an important monitoring and control content for the normal operation of gas storage reservoirs, and is an important parameter to help production technicians analyze and judge the working status of gas storage reservoirs. The performance of gas storage reservoirs depends to a large extent on the inventory in the gas storage reservoirs, so the gas storage reservoirs must be continuously monitored to calibrate whether the calculated results are consistent with the observed results; on the second hand, engineering tasks such as identifying the leakage mechanism of gas storage reservoirs and optimizing injection and production plans also require accurate calculation of inventory. Thirdly, the peak-shaving function requirement of gas storage determines that the operation characteristics of strong injection and strong production of gas storage are different from the operation characteristics of planned stable injection and production of conventional gas reservoirs. The production is unstable and discontinuous, strong injection and strong production are carried out alternately, gas injection and production are quickly switched, and the formation pressure is rapidly increased and rapidly released. The gas reservoir is in an excited state for a long time, the time for the shut-in pressure to restore equilibrium is short, and the formation pressure during the equilibrium period is difficult to obtain accurately. The pressure obtained by the shut-in test of the monitoring well cannot directly reflect the formation pressure during the equilibrium period of the gas storage. Therefore, the pressure-inventory curve no longer follows the linear law during the injection and production process, and a lag effect occurs. Fourthly, the natural gas compression factor is closely related to temperature and pressure. The existing research methods mainly determine the natural gas compression factor by laboratory data fitting. Since the gas component content, temperature and pressure will change in real time during different injection and production cycles, it is difficult to accurately obtain the natural gas compression factor under the operation state of the gas storage. Therefore, a set of evaluation methods for gas storage inventory calculation is urgently needed to provide strong technical support for the stable operation of the gas storage.

[0057] In an embodiment of the present invention, a method for evaluating gas storage inventory is provided. Figure 1 As shown, it may include:

[0058] Step S11: construct a partitioned flow model of injection and production wells in the gas storage according to the strong injection and strong production characteristic parameters of the gas storage, and establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of injection and production wells.

[0059] Step S12: determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method.

[0060] Step S13: Determine the average formation pressure of the gas storage based on the formation pressures of all the single wells included in the gas storage.

[0061] Step S14: Determine the gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage.

[0062] Step S15: determining the inventory of the gas storage reservoir based on the gas compressibility factor and the average formation pressure of the gas storage reservoir, and constructing a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart in combination with the measured data.

[0063] The above method provided in the embodiment of the present invention first establishes a mathematical model for calculating the average formation pressure of a single well based on the seepage mechanics theory, then uses the well control volume weighted method to solve the influence of well interference and obtain the average formation pressure of the gas storage reservoir; then the gas compression factor is determined based on the average formation pressure and the gas component content and the reservoir and reservoir temperature, and finally the actual inventory can be calculated.

[0064] Furthermore, the embodiment of the present invention is compared with the measured data, and the errors of pressure and compression factor are corrected based on the error theory analysis method, and the inventory calculation mathematical model based on the error theory is obtained, and the error theory chart is established. Compared with the traditional numerical simulation method, the embodiment of the present invention is simple to calculate and easy to operate, and the time of inventory evaluation calculation is minimized while ensuring the accuracy of the calculation results.

[0065] In a detailed embodiment, referring to Figure 2 As shown, the above-mentioned gas storage inventory evaluation method may specifically include:

[0066] Step S21: pre-constructing a gas storage reservoir inventory calculation correction model based on the geological characteristic parameters of the gas storage reservoir.

[0067] The inventors found that the corresponding relationship between the pressure and inventory of the underground gas storage facility rebuilt based on the natural gas reservoir no longer follows the linear law during the injection and production process, and a hysteresis effect occurs. The embodiment of the present invention assumes that the injection and production gas volume and the pseudo-pressure of the gas reservoir satisfy the pressure rise and fall equation within an injection and production cycle, and considers the error of the average formation pressure to establish an inventory calculation correction model as follows:

[0068]

[0069] Among them, I is the inventory, m 3 ;

[0070] ΔQ is the gas production or injection volume, m 3 ;

[0071] p is the average formation pressure of the gas storage, MPa;

[0072] Z is the gas compressibility factor, dimensionless;

[0073] T is the reservoir temperature, K;

[0074] ε is the relative error of the unbalanced state of the gas storage;

[0075] Wherein, subscripts 1 and 2 represent the end of gas injection and the end of gas production, respectively.

[0076] Step S22: performing quantitative error analysis on the inventory calculation correction model to construct an inventory relative error calculation model for the gas storage.

[0077] In this step, through quantitative error analysis, the error of inventory calculation correction model I comes from the measurement errors of ΔQ, p, Z and T. Based on the error theory analysis, the relative error calculation model of inventory is obtained:

[0078] The relative error calculation (addition and subtraction) of two positive numbers is:

[0079]

[0080] Where: x 1 and x 2 is any real number, For x 1 The relative error, For x 2 The relative error of .

[0081] Relative error of the product:

[0082]

[0083] Relative error of the quotient:

[0084]

[0085] Therefore, the relative error calculation model of inventory can be obtained as follows:

[0086]

[0087] Step S23: construct a partitioned flow model of the injection and production wells in the gas storage according to the strong injection and strong production characteristic parameters of the gas storage, and establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells.

[0088] Due to the different reservoir characteristics, this step divides the seepage area of ​​the gas storage reservoir with different seepage fields into two seepage areas based on the seepage theory, and establishes a single well formation pressure model. In the embodiment of the present invention, the pressure solution in the pull-type space is obtained by using the dimensionless definition and Laplace transformation. The dimensionless bottom hole pressure solution in the pull-type space without considering the wellbore storage coefficient and the skin coefficient is:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094] Where: is the dimensionless bottom hole pressure;

[0095] u is the Laplace variable;

[0096] r fD is the dimensionless composite radius;

[0097] M is the mobility ratio;

[0098] σ is the pressure conductivity ratio;

[0099] I 0 is the zero-order Bessel function of the first kind;

[0100] I 1 is the first-order Bessel function of the first kind;

[0101] K 0 is the zero-order Bessel function of the second kind;

[0102] K 1 is the first-order Bessel function of the second kind;

[0103] According to the Duhamel principle, the dimensionless bottom hole pressure solution without considering the wellbore storage coefficient and skin coefficient can be transformed into the dimensionless bottom hole pressure solution considering the wellbore storage coefficient and skin coefficient:

[0104]

[0105] Where: S is the skin factor;

[0106] C D is the dimensionless wellbore storage coefficient;

[0107] In the embodiment of the present invention, the Bessel function in the pressure solution is simplified by a polynomial fitting method, and the change of bottom hole pressure is calculated by Stehfest numerical inversion; when the well is shut-in time is long enough, the bottom hole pressure is the average formation pressure of the well.

[0108] Step S24, determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method.

[0109] In the specific implementation, the gas component content of the injected and produced gas, the reservoir temperature, the production data and the pressure recovery data or the pressure drop data during the operation cycle of the gas storage reservoir are firstly collected; then, based on the unstable well test analysis method, the test well is subjected to double logarithmic fitting, semi-logarithmic fitting and production history data fitting to obtain the single well formation pressure calculation parameters of the test well, wherein the single well formation pressure calculation parameters include: wellbore storage coefficient, skin coefficient, permeability, mobility ratio and composite radius; finally, the single well formation pressure calculation parameters are brought into the single well formation pressure model to determine the single well formation pressure.

[0110] In a specific example, take gas storage A as an example. The gas layer thickness of gas storage A is 21.5m, the porosity is 0.209, and the gas layer permeability is 25mD; the gas well radius is 0.1m, and the comprehensive compression coefficient is 0.0192MPa. -1 The reservoir temperature is 375K. Seven days after the completion of gas injection, the pressure of multiple gas injection wells was measured, and the average value was 23.82MPa.

[0111] In this example, the reservoir temperature of gas storage A is 375K, the components of injected gas are shown in Table 1, and the calculation parameters of single well formation pressure obtained by the unstable well test analysis method are shown in Table 2.

[0112] Table 1 Gas component content

[0113]

[0114] Table 2 Unsteady well test interpretation parameters

[0115]

[0116] Step S25: Determine the average formation pressure of the gas storage based on the formation pressures of all the single wells included in the gas storage. In this step, the average formation pressure of the gas storage is calculated by weighting the well-controlled volume of multiple wells using the average formation pressure of the single well.

[0117] In specific implementation, the average formation pressure calculation parameters obtained by the unstable well test method are combined with the pressure calculation formula of a single well to calculate the average formation pressure of a single well. The average formation pressure of a single well is calculated by weighting the well control volume of multiple wells to calculate the average formation pressure of the gas storage reservoir. When the distance d between the two wells is less than the sum of the well control radii r of the two wells, e1 +r e2 , determine that there is interference between the two wells, and modify the well control range of each well by calculating the volume of the interference area;

[0118] Reference Figure 3 As shown, the vertical well interference area

[0119]

[0120] Where: S vert is the interference area of ​​the vertical well, r e is the well control radius, and d is the distance between the two wells.

[0121] Reference Figure 4 As shown, the horizontal well interference area

[0122]

[0123] Where: S ellipse is the interference area of ​​the horizontal well, a and b are the major axis and minor axis of the elliptical seepage field of the horizontal well, respectively, and d is the distance between the two wells.

[0124] The average formation pressure of the well-controlled volume of a single well is weighted by using the corrected well-controlled volume to calculate the average formation pressure of the gas storage reservoir:

[0125]

[0126] Where: p is the average formation pressure of a single well, MPa;

[0127] r e is the control radius of a single well, m;

[0128] S is the area of ​​interference zone, m 2 ;

[0129] h is the reservoir thickness, m;

[0130] φ is the porosity;

[0131] n is the total number of injection and production wells in the gas storage;

[0132] Subscripts i and j represent well numbers.

[0133] Step S26: Determine the gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage. In the specific implementation of this step, the national standard AGAB-92DC method can be used to calculate the gas compression factor based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage.

[0134] Step S27: determining the inventory of the gas storage reservoir based on the gas compressibility factor and the average formation pressure of the gas storage reservoir, and constructing a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart in combination with the measured data.

[0135] In this step, after obtaining parameters such as the gas compression factor and the average formation pressure of the gas storage reservoir, the inventory of the gas storage reservoir can be accurately calculated.

[0136] Step S28, based on the gas compression factor, average formation pressure, inventory of the gas storage and the measured gas compression factor, average formation pressure and inventory, and the inventory relative error calculation model, determine the relative error of the unbalanced state of the gas storage.

[0137] In this step, the relative error of the unbalanced state of the gas storage reservoir is determined, which can specifically include: determining the relative error of the inventory based on the gas compression factor, average formation pressure, and inventory of the gas storage reservoir and the measured gas compression factor, average formation pressure, and inventory, so as to correct the inventory of each injection and production cycle of the gas storage reservoir and establish a curve of inventory error versus pressure error.

[0138] Calculate the relative error caused by the measurement accuracy of flowmeter and thermometer during gas injection and production and According to the single well test pressure after each injection and production cycle of the gas storage, the average formation pressure and compression factor when the gas storage has not reached the equilibrium state are calculated by the well control volume weighting method. The relative error of the average formation pressure and compression factor caused by the gas storage not returning to the equilibrium period due to the short shut-in equilibrium time is calculated:

[0139]

[0140]

[0141] Where: and is the average formation pressure and gas compression factor when the gas storage reaches the equilibrium period after the well is shut in. and are the average formation pressure and gas compression factor during the shut-in test period of the gas storage facility.

[0142] The relative error of the inventory can be calculated by substituting the average formation pressure, gas compression factor, reservoir temperature and relative error of the average formation pressure and gas compression factor during the shut-in test period of the gas storage reservoir into the inventory relative error calculation model of step S22, and then the relative error of the inventory can be drawn.

[0143] In the above example, due to the high accuracy of the meter and thermometer, the errors of the injection and production gas volume and temperature can be ignored. The calculation results of parameters such as pressure and compression factor at the end of injection and production are shown in Table 3.

[0144] Table 3 Calculation parameters

[0145]

[0146] It should be noted that in the above Table 3, the effective inventory volume obtained by the error theory simulation calculation in the embodiment of the present invention is compared with the effective inventory volume obtained by numerical simulation in the prior art. The error is within 5%, the error is small, and the method is simple to calculate and easy to operate, which fully meets the engineering calculation requirements. However, based on the numerical simulation technology, it takes as little as several months and as much as several years, which obviously has obvious disadvantages compared with the above method in the embodiment of the present invention.

[0147] Step S29: construct a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart based on the relative error of the unbalanced state of the gas storage. Figure 5 and Figure 6 As shown, a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart is constructed based on the above relative error to facilitate rapid calculation of the inventory of the gas storage reservoir.

[0148] Based on the same inventive concept, an embodiment of the present invention also provides a method for determining the inventory of a gas storage reservoir, which may include: determining the effective inventory of the gas storage reservoir based on the measured average formation pressure of the gas storage reservoir, the gas compression factor and the injection and production gas volume, as well as the pressure drop-inventory error map and / or the pseudo-pressure error-inventory error map; wherein the pressure drop-inventory error map and / or the pseudo-pressure error-inventory error map are obtained in advance based on the above-mentioned gas storage reservoir inventory evaluation method.

[0149] Based on the same inventive concept, a gas storage inventory evaluation device is also provided in the embodiment of the present invention, referring to Figure 7 As shown, it may include:

[0150] The single well formation pressure model building module 73 is used to build a partitioned flow model of the injection and production wells in the gas storage according to the strong injection and strong production characteristic parameters of the gas storage, so as to establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells;

[0151] The single well formation pressure determination module 74 is used to determine the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method;

[0152] The gas storage average formation pressure determination module 75 is used to determine the average formation pressure of the gas storage based on the formation pressures of all single wells included in the gas storage;

[0153] The gas compression factor determination module 76 is used to determine the gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage;

[0154] The inventory determination module 77 is used to determine the inventory of the gas storage based on the gas compression factor and the average formation pressure of the gas storage;

[0155] The map construction module 78 is used to construct a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map in combination with the measured data.

[0156] In an alternative embodiment, referring to Figure 7 As shown, the device may further include: an inventory model pre-building module 71 and a relative error determination module 72;

[0157] The inventory model pre-construction module 71 is used to pre-construct an inventory calculation correction model of the gas storage reservoir based on the geological characteristic parameters of the gas storage reservoir; and to perform quantitative error analysis on the inventory calculation correction model to construct an inventory relative error calculation model of the gas storage reservoir;

[0158] The relative error determination module 72 is used to determine the relative error of the unbalanced state of the gas storage based on the gas compression factor, average formation pressure, inventory and measured gas compression factor, average formation pressure and inventory of the gas storage, and the inventory relative error calculation model.

[0159] In another optional embodiment, the map construction module 77 is specifically used to construct a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map based on the relative error of the unbalanced state of the gas storage.

[0160] In another optional embodiment, the relative error determination module 72 is specifically used to determine the relative error of the inventory based on the gas compression factor, average formation pressure, and inventory of the gas storage reservoir and the measured gas compression factor, average formation pressure, and inventory, so as to correct the inventory of each injection and production cycle of the gas storage reservoir and establish a curve of inventory error versus pressure error.

[0161] Based on the same inventive concept, 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 above-mentioned gas storage inventory evaluation method is implemented.

[0162] Based on the same inventive concept, a computer device is also provided in an embodiment of the present invention, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the above-mentioned gas storage inventory evaluation method is implemented when the processor executes the program.

[0163] The principles of the problems solved by the above-mentioned devices, media, and related equipment in the embodiments of the present invention are similar to those of the above-mentioned methods, so their implementation can refer to the implementation of the above-mentioned methods, and the repeated parts will not be repeated.

[0164] 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 and optical storage, etc.) containing computer-usable program code.

[0165] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (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 processor, or other programmable data processing device to produce 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.

[0166] 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.

[0167] 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.

[0168] 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 evaluating gas storage inventory, characterized in that: include: According to the strong injection and strong production characteristic parameters of the gas storage, a partitioned flow model of the injection and production wells in the gas storage is constructed, so as to establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells; Determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method; Determining an average formation pressure of the gas storage based on the formation pressures of all single wells included in the gas storage; Determining the gas compressibility factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage; The inventory of the gas storage reservoir is determined based on the gas compressibility factor and the average formation pressure of the gas storage reservoir, so as to construct a pressure drop-inventory error chart and / or a pseudo-pressure error-inventory error chart in combination with measured data.

2. The method according to claim 1, characterized in that Also includes: Based on the geological characteristic parameters of the gas storage reservoir, a gas storage reservoir inventory calculation correction model is pre-built; Performing quantitative error analysis on the inventory calculation correction model to construct an inventory relative error calculation model for the gas storage facility; Based on the gas compression factor, average formation pressure, inventory and measured gas compression factor, average formation pressure and inventory of the gas storage reservoir, and the inventory relative error calculation model, the relative error of the unbalanced state of the gas storage reservoir is determined.

3. The method according to claim 2, characterized in that Also includes: Based on the relative error of the unbalanced state of the gas storage, a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map is constructed.

4. The method according to claim 2, characterized in that: Determining the relative error of the unbalanced state of the gas storage includes: The relative error of the inventory is determined based on the gas compression factor, average formation pressure, and inventory of the gas storage reservoir and the measured gas compression factor, average formation pressure, and inventory, so as to correct the inventory of each injection and production cycle of the gas storage reservoir and establish a curve of inventory error versus pressure error.

5. The method according to claim 2, characterized in that: The inventory calculation correction model is: Among them, I is the inventory, m 3 ; ΔQ is the gas production or injection volume, m 3 ; p is the average formation pressure of the gas storage, MPa; Z is the gas compressibility factor, dimensionless; T is the reservoir temperature, K; ε is the relative error of the unbalanced state of the gas storage; Wherein, subscripts 1 and 2 represent the end of gas injection and the end of gas production, respectively.

6. The method according to any one of claims 1 to 5, characterized in that: Determining the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method includes: Collecting gas component content of injected and produced gas, reservoir temperature, production data and pressure recovery data or pressure drop data during the operation cycle of the gas storage reservoir; Based on the unstable well test analysis method, double logarithmic fitting, semi-logarithmic fitting and production history data fitting are performed on the test well to obtain the single well formation pressure calculation parameters of the test well, wherein the single well formation pressure calculation parameters include: wellbore storage coefficient, skin coefficient, permeability, mobility ratio and composite radius; The single well formation pressure calculation parameters are brought into the single well formation pressure model to determine the single well formation pressure.

7. A method for determining the inventory of a gas storage facility, characterized in that: include: Determine the effective inventory of the gas storage according to the measured average formation pressure, gas compressibility factor and injection and production volume of the gas storage, as well as the pressure drop-inventory error chart and / or the pseudo-pressure error-inventory error chart; The pressure drop-inventory error chart and / or the pseudo-pressure error-inventory error chart are obtained in advance according to the gas storage inventory evaluation method according to any one of claims 1 to 6.

8. A gas storage inventory evaluation device, characterized in that: include: A single well formation pressure model building module is used to build a partitioned flow model of the injection and production wells in the gas storage according to the strong injection and strong production characteristic parameters of the gas storage, so as to establish a single well formation pressure model based on the seepage field characteristics and the partitioned flow model of the injection and production wells; A single well formation pressure determination module, used to determine the formation pressure of the single well based on the single well formation pressure model and the single well formation pressure calculation parameters obtained based on the unstable well test analysis method; A gas storage reservoir average formation pressure determination module, used to determine the average formation pressure of the gas storage reservoir based on the formation pressures of all single wells included in the gas storage reservoir; A gas compression factor determination module, used to determine the gas compression factor of the gas storage based on the average formation pressure of the gas storage, the gas component content of the injected and produced gas of the gas storage, and the reservoir temperature of the gas storage; An inventory determination module, configured to determine the inventory of the gas storage based on the gas compression factor and the average formation pressure of the gas storage; A map construction module is used to construct a pressure drop-inventory error map and / or a pseudo-pressure error-inventory error map in combination with measured data.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the gas storage inventory evaluation method according to any one of claims 1 to 6 is implemented.

10. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the gas storage inventory evaluation method according to any one of claims 1 to 6 is implemented.

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