Method, device and electronic equipment for determining Langmuir adsorption model of shale gas reservoir

Abstract

The present application is applicable to the field of natural gas exploration technology, and provides a method, device and electronic device for determining the Langmuir adsorption model of a shale gas reservoir. The method for determining the Langmuir adsorption model of a shale gas reservoir includes: obtaining the reservoir parameters of the target shale gas reservoir and the percentage of each substance; determining the adsorbed gas volume of the target shale gas reservoir according to the reservoir parameters; establishing the Langmuir volume formula and the Langmuir pressure formula according to the percentage of each substance; substituting the adsorbed gas volume, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir, and solving to obtain the Langmuir adsorption model parameters of the target shale gas reservoir. The embodiments of the present application have the advantages of low sample specification requirements, low cost, simple process, short time period and small deviation.

Description

Technical Field

[0001] The present application belongs to the field of natural gas exploration technology, and in particular relates to a method, device and electronic equipment for determining a Langmuir adsorption model of a shale gas reservoir. Background Art

[0002] The Langmuir adsorption model was proposed by physical chemist Irving Langmuir in 1916 based on the molecular kinetic theory and some assumptions. It is a theoretical model that describes the adsorption behavior of substances in gas or solution on solid surfaces. This model mainly describes the adsorption phenomenon of a single molecular layer. The Langmuir equation is the mathematical expression of the Langmuir adsorption model, and its expression is V = V L P / (P+P L ), where V represents the adsorption capacity, P represents the pressure, and V L represents the Langmuir volume, P L represents the Langmuir pressure. Langmuir volume V L and Langmuir pressure P L These are two fundamental parameters in the Langmuir adsorption model. The Langmuir adsorption model is widely used to study the behavior of adsorbed unconventional natural gas in reservoirs, particularly in shale gas and coalbed methane research. Shale gas reservoirs primarily contain organic matter and clay minerals, and the Langmuir adsorption model parameters are often statistically correlated with the content of these components.

[0003] Determination of Langmuir adsorption model parameters of shale gas reservoirs Langmuir volume V L and Langmuir pressure P L The method is mainly based on the results of isothermal adsorption experiments. The Langmuir adsorption model parameter Langmuir volume V can be determined by fitting the isothermal adsorption experimental data to the Langmuir equation. L and Langmuir pressure P L. In addition, based on the statistical expressions of Langmuir adsorption model parameter data measured by isothermal adsorption experiments of some samples and other experimental test data or geological data (such as the content of different substances in shale reservoirs, logging data, thermal evolution degree characterization parameters, etc.), the Langmuir adsorption model parameters can be further predicted. It is not difficult to find that the relevant shale gas reservoir Langmuir adsorption model parameter determination methods mainly have the following problems: (1) The shale gas reservoir Langmuir adsorption model parameter determination method requires relatively precise isothermal adsorption instruments and related supporting equipment, and the samples required for the experiment need to be processed into specific specifications and processed to a certain benchmark state. The experiment needs to be carried out in a laboratory that meets a series of conditions; (2) The shale gas reservoir Langmuir adsorption model parameter determination method requires samples to be brought from the site to the laboratory, and the experimental cost is relatively expensive and the process is complicated; (3) The shale gas reservoir Langmuir adsorption model parameter determination method requires a long time period, especially In the case of a large number of samples, the data acquisition cycle may be too long, which may lead to the inability to meet immediate research needs; (4) The method for determining the parameters of the Langmuir adsorption model of shale gas reservoirs requires manual operation, and the professional and technical level of the experimenters, the operation of experimental details and the equipment conditions of the laboratory may lead to certain deviations and incomparability of the experimental results, and even the risk of experimental failure; (5) The method for determining the parameters of the Langmuir adsorption model of shale gas reservoirs can only obtain data on the adsorption parameters, and involves less related parameters that affect the adsorption of shale reservoirs, which is difficult to meet the needs of correlation research and overall understanding of different factors of shale gas.

[0004] Given that the determination of the Langmuir adsorption model parameters of shale gas reservoirs is the basic content of shale gas research, it is necessary to scientifically and rationally determine the Langmuir adsorption model parameters of shale gas reservoirs, such as the Langmuir volume V. L and Langmuir pressure P L This is of great significance for understanding the mechanism of shale gas accumulation and enrichment, guiding shale gas exploration and development, and improving the level of understanding of shale gas geology. Therefore, a method for determining the Langmuir adsorption model of shale gas reservoirs that can solve the above problems is needed. Summary of the Invention

[0005] In order to overcome the problems existing in the related technologies such as strict sample specification restrictions, high costs, complex processes, long time periods, large deviations, and little involvement of relevant parameters affecting the adsorption of shale reservoirs, the embodiments of the present application provide a method, device and electronic equipment for determining the Langmuir adsorption model of shale gas reservoirs.

[0006] This application is achieved through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a method for determining a Langmuir adsorption model of a shale gas reservoir, comprising:

[0008] Obtain the reservoir parameters and percentage content of each substance of the target shale gas reservoir;

[0009] determining the adsorbed gas volume of the target shale gas reservoir according to the reservoir parameters;

[0010] According to the percentage content of each substance, a Langmuir volume formula and a Langmuir pressure formula are respectively established; wherein the Langmuir volume formula is a statistical relationship function between the Langmuir volume and the percentage content of each substance; and the Langmuir pressure formula is a statistical relationship function between the Langmuir pressure and the percentage content of each substance;

[0011] The adsorbed gas amount, the Langmuir volume formula, and the Langmuir pressure formula are substituted into the Langmuir adsorption model of the target shale gas reservoir to obtain the Langmuir adsorption model parameters of the target shale gas reservoir.

[0012] In some embodiments, determining the adsorbed gas capacity of the target shale gas reservoir according to the reservoir parameters includes:

[0013] Obtaining the gas saturation and total gas content of the target shale gas reservoir;

[0014] Determining the free gas volume of the target shale gas reservoir according to the reservoir parameters and the gas saturation of the target shale gas reservoir;

[0015] The adsorbed gas content of the target shale gas reservoir is determined by subtracting the free gas content of the target shale gas reservoir from the total gas content of the target shale gas reservoir.

[0016] In some embodiments, the reservoir parameters include porosity, reservoir pressure, apparent density, and reservoir temperature of the target shale gas reservoir;

[0017] Determining the free gas volume of the target shale gas reservoir according to the reservoir parameters and the gas saturation of the target shale gas reservoir includes:

[0018] pass Calculating the free gas volume of the target shale gas reservoir;

[0019] Among them, Q fr is the free gas volume of the target shale gas reservoir; Z0 and Z r are the shale gas compressibility factors under standard conditions and reservoir conditions, respectively; Sg is the gas saturation of the target shale gas reservoir; is the porosity of the target shale gas reservoir; T0 is the gas thermodynamic temperature under standard conditions, T0 = 273.15K; P r is the reservoir pressure of the target shale gas reservoir; ρ b is the apparent density of the target shale gas reservoir; T r is the reservoir temperature of the target shale gas reservoir; P0 is the reservoir pressure under standard conditions, P0 = 0.101325 MPa.

[0020] In some embodiments, the Langmuir volume formula is:

[0021]

[0022] Among them, Q L is the Langmuir volume; k i-Q is the volume coefficient; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; c Q is the volume constant;

[0023] The Langmuir pressure formula is:

[0024]

[0025] Among them, P L is the Langmuir pressure; k i-P is the pressure coefficient; c P is the pressure constant;

[0026] The Langmuir adsorption model is:

[0027]

[0028] Among them, Q ad is the adsorbed gas volume of the target shale gas reservoir; P r is the reservoir pressure of the target shale gas reservoir.

[0029] In some embodiments, substituting the adsorbed gas amount, the Langmuir volume formula, and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir to obtain the Langmuir adsorption model parameters of the target shale gas reservoir includes:

[0030] Substituting the Langmuir volume formula and the Langmuir pressure formula into the expression of the Langmuir adsorption model to determine the equation to be solved;

[0031] Substituting the reservoir parameters, the percentage content of each substance, and the adsorbed gas volume of the target shale gas reservoir into the equation to be solved, and solving the equation to be solved to determine the volume coefficient and volume constant in the Langmuir volume formula, and the pressure coefficient and pressure constant in the Langmuir pressure formula; wherein the volume coefficient is the coefficient of each substance component in the Langmuir volume formula; the volume constant is the constant term in the Langmuir volume formula; the pressure coefficient is the coefficient of each substance component in the Langmuir pressure formula; and the pressure constant is the constant term in the Langmuir pressure formula;

[0032] Based on the volume coefficient, the volume constant, the pressure coefficient, the pressure constant and the percentage content of each substance, the Langmuir adsorption model parameters of the target shale gas reservoir are determined.

[0033] In some embodiments, the equation to be solved is:

[0034]

[0035] Among them, P r is the reservoir pressure of the target shale gas reservoir; i is the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; Q ad k is the adsorbed gas volume of the target shale gas reservoir; i-Q is the volume coefficient; k i-P is the pressure coefficient; c Q is the volume constant; c P is the pressure constant.

[0036] In some embodiments, the Langmuir adsorption model parameters of the target shale gas reservoir include the Langmuir volume and the Langmuir pressure;

[0037] Determining the Langmuir adsorption model parameters of the target shale gas reservoir based on the volume coefficient, the volume constant, the pressure coefficient, the pressure constant, and the percentage of each substance includes:

[0038] Substituting the volume coefficient, the volume constant, and the percentage content of each substance into the Langmuir volume formula to determine the Langmuir volume;

[0039] The pressure coefficient, the pressure constant and the percentage content of each substance are substituted into the Langmuir pressure formula to determine the Langmuir pressure.

[0040] In a second aspect, an embodiment of the present application provides a device for determining a Langmuir adsorption model of a shale gas reservoir, comprising:

[0041] An acquisition module is used to obtain reservoir parameters and percentage content of various substances of the target shale gas reservoir;

[0042] a calculation module, configured to determine the adsorbed gas volume of the target shale gas reservoir according to the reservoir parameters;

[0043] A construction module is used to establish a Langmuir volume formula and a Langmuir pressure formula according to the percentage content of each substance; wherein the Langmuir volume formula is a statistical relationship function between the Langmuir volume and the percentage content of each substance; and the Langmuir pressure formula is a statistical relationship function between the Langmuir pressure and the percentage content of each substance;

[0044] A solution module is used to substitute the adsorbed gas amount, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir to obtain the Langmuir adsorption model parameters of the target shale gas reservoir.

[0045] In a third aspect, an embodiment of the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for determining the Langmuir adsorption model of a shale gas reservoir as described in any one of the first aspects is implemented.

[0046] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for determining the Langmuir adsorption model of a shale gas reservoir as described in any one of the first aspects is implemented.

[0047] In a fifth aspect, an embodiment of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the method for determining the Langmuir adsorption model of a shale gas reservoir described in any one of the first aspects above.

[0048] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0049] The beneficial effects of the embodiments of the present application compared with the related art are: the embodiments of the present application fully consider the intrinsic connection between the Langmuir adsorption model parameters of the shale gas reservoir and the adsorption components of the shale reservoir, and make full use of the statistical relationship expression between the two as a medium to determine the Langmuir adsorption model parameters, which can effectively avoid isothermal adsorption experimental analysis with strict sample specification restrictions, high costs, long time periods and high instrument and equipment requirements, and can calculate a large number of adsorption model parameters in a short time, while obtaining shale reservoir and gas content information.

[0050] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0052] Figure 1 This is a schematic flow chart of a method for determining a Langmuir adsorption model for a shale gas reservoir provided in one embodiment of the present application;

[0053] Figure 2 Schematic diagram of the structure of the device for determining the Langmuir adsorption model of a shale gas reservoir provided in an embodiment of the present application;

[0054] Figure 3 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0056] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0057] It will also be understood that the term "and / or" used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0058] As used in this specification and the appended claims, the term "if" can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0059] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0060] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present application. Thus, phrases such as "in one embodiment," "in some embodiments," "in other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0061] When determining the Langmuir adsorption model parameters of shale gas reservoirs through isothermal adsorption experiments, there are disadvantages and shortcomings such as strict sample specification restrictions, high costs, long time periods, and high requirements for instrumentation and equipment.

[0062] Based on the above problems, the present invention proposes a method for determining the Langmuir adsorption model of a shale gas reservoir. Based on the material composition and gas content of the shale gas reservoir, a set of equations for different samples can be constructed with the help of the statistical relationship expression between the content of the adsorbent component in the shale gas reservoir and the amount of gas adsorbed by the shale gas. By solving the set of equations, the relevant parameters in the statistical relationship expression between the content of the adsorbent component and the amount of gas adsorbed by the shale gas can be determined. Based on this, the Langmuir adsorption model parameter Langmuir volume V of the shale sample to be evaluated can be further determined. L and Langmuir pressure P L .

[0063] The method proposed in this application can calculate the Langmuir adsorption model parameters of shale gas reservoirs in any shale gas well, primarily because it takes into account the unique conditions of the shale gas reservoir itself within a single shale gas well. For a specific shale gas, the thickness of shale gas reservoirs typically developed industrially is only a dozen to several dozen meters. On the one hand, the formation temperatures of the entire shale reservoir involved in the shale gas well are not significantly different and can be considered isothermal. On the other hand, the formation environment and the material components that affect adsorption of the limited-scale shale gas reservoirs studied in the same well are extremely consistent, and it can be considered that the main controlling factors affecting the adsorption parameters of the shale gas reservoir are consistent.

[0064] Gas content testing was performed on shale samples collected from the shale gas wells under study, and shale reservoir parameters were analyzed for these samples. The collection of shale samples must be fully representative, with particular attention paid to differences in lithology, composition, and gas content. Furthermore, the number of shale samples tested and analyzed must meet the requirements for the subsequent construction of the Langmuir adsorption model for shale gas reservoir parameters.

[0065] Figure 1 This is a schematic flow chart of a method for determining a Langmuir adsorption model for a shale gas reservoir provided in one embodiment of the present application, with reference to Figure 1 The method for determining the Langmuir adsorption model of the shale gas reservoir is described in detail as follows:

[0066] In S101, the reservoir parameters of the target shale gas reservoir and the percentage content of each substance are obtained.

[0067] Among them, reservoir parameters include porosity, reservoir pressure, apparent density and reservoir temperature of the target shale gas reservoir.

[0068] In the examples of this application, the shale gas reservoir parameters that need to be obtained mainly include TOC, mineral composition, apparent density, porosity, reservoir temperature, and reservoir pressure. The TOC content of the shale reservoir can be experimentally obtained with reference to the standard "Determination of Total Organic Carbon in Sedimentary Rocks" (GB / T 19145-2003), and the shale mineral composition can be tested and obtained in accordance with the national standard "X-ray Diffraction Analysis Method for Clay Minerals and Common Non-Clay Minerals in Sedimentary Rocks" (SY / T 5163-2018).

[0069] Apparent density of shale reservoir ρ b (Unit is t / m 3 ) and the initial porosity of shale under laboratory conditions (Percentage content) can be obtained according to the "Test Procedures for Rock Physical and Mechanical Properties Part 4: Rock Density Test" (DZ / T 0276.4-2015) and the standard "Determination of Shale Porosity, Permeability and Saturation" (GB / T34533-2023). Due to the effect of formation stress, the porosity values ​​of shale reservoirs under experimental conditions and reservoir conditions are not consistent. The pore compression coefficient can be obtained based on laboratory overburden pressure experiments, and then the porosity under reservoir conditions can be calculated.

[0070] Reservoir temperature T r (Unit is K) can be obtained by analyzing well temperature logging results or calculating geothermal gradient. Reservoir pressure P r (Unit: MPa) can be obtained from well test data, or calculated using the following formula based on the regional reservoir pressure gradient or pressure coefficient distribution law:

[0071] P r =10 -6 f P ρ w gH

[0072] In the formula, f P represents the reservoir pressure coefficient, dimensionless; H is the burial depth of the shale reservoir, in meters; ρ w is the density of water, which is 1×10 3 kg / m; g is the acceleration due to gravity, which is 9.8N / kg.

[0073] In S102, the adsorbed gas volume of the target shale gas reservoir is determined based on the reservoir parameters.

[0074] In some embodiments of the present application, the adsorbed gas amount of the target shale gas reservoir may be determined by the following steps:

[0075] In S1021, the gas saturation and total gas content of the target shale gas reservoir are obtained.

[0076] Among them, the gas saturation of shale reservoir S g (in percentage form) can be obtained through well logging interpretation or shale reservoir water content calculation; according to "SY / T 6940-2020 Shale Gas Content Determination Method", the total gas content Q of the target shale gas reservoir can be obtained (in m 3 / t).

[0077] In S1022, the free gas volume of the target shale gas reservoir is determined based on the reservoir parameters and the gas saturation of the target shale gas reservoir.

[0078] Optional, by Calculate the free gas volume of the target shale gas reservoir.

[0079] Among them, Q fr is the free gas volume of the target shale gas reservoir; Z0 and Z r are the shale gas compressibility factors (dimensionless) under standard conditions and reservoir conditions, respectively; S g is the gas saturation of the target shale gas reservoir, expressed as a percentage; is the porosity of the target shale gas reservoir, expressed as a percentage; T0 is the thermodynamic temperature of the gas under standard conditions, T0 = 273.15 K; P r is the reservoir pressure of the target shale gas reservoir, in MPa; ρ b is the apparent density of the target shale gas reservoir, in t / m 3 ;T r is the reservoir temperature of the target shale gas reservoir, in K; P0 is the reservoir pressure under standard conditions, P0 = 0.101325 MPa.

[0080] In S1023, the free gas content of the target shale gas reservoir is subtracted from the total gas content of the target shale gas reservoir to determine the adsorbed gas content of the target shale gas reservoir.

[0081] For example, through Q ad =QQ fr Determine the adsorbed gas volume Q of the target shale gas reservoir ad (Unit is m 3 / t).

[0082] It should be understood that the above-mentioned gas saturation, total gas content, free gas content and adsorbed gas content are all gas content parameters of shale gas reservoirs.

[0083] In S103, Langmuir volume formula and Langmuir pressure formula are established according to the percentage content of each substance.

[0084] The Langmuir volume formula is a statistical function of the relationship between the Langmuir volume and the percentage content of each substance; the Langmuir pressure formula is a statistical function of the relationship between the Langmuir pressure and the percentage content of each substance.

[0085] It should be noted that the Langmuir adsorption model parameter Q of shale gas reservoir is L and P L Affected by the material composition of organic matter and minerals in shale reservoirs, organic matter is usually characterized by the parameter TOC, and the minerals that have a greater impact on adsorption behavior are mainly clay minerals, including montmorillonite, kaolinite, chlorite, illite, and mixed layers of illite and montmorillonite.

[0086] The same well ensures the consistency of geological background, and the Langmuir adsorption model parameter Q of shale gas reservoir L and P L Only affected by the composition of shale reservoir materials. Langmuir adsorption model parameter Q L and P L The statistical relationship function between ω(i) and the percentage content of shale gas reservoir materials can be expressed by a multivariate linear relationship.

[0087] Alternatively, the Langmuir volume formula is:

[0088]

[0089] Among them, Q L is the Langmuir volume, is the reservoir temperature T r The maximum adsorption capacity of shale reservoir under the conditions, unit is m 3 / t; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; k i-Q is the volume coefficient, expressed in Q L The coefficient of the i-th material component in the multivariate linear relationship between the percentage of the target shale gas reservoir material component; c Q is the volume constant, indicating that Q L The constant term in the multivariate linear relationship between the percentage content of the target shale gas reservoir material components.

[0090] The Langmuir pressure formula is:

[0091]

[0092] Among them, P Lis the Langmuir pressure, which is the Langmuir constant related to the adsorption activation energy, and its unit is MPa; k i-P is the pressure coefficient, expressed in P L The coefficient of the i-th material component in the multivariate linear relationship between the percentage of shale gas reservoir material components; c P is the pressure constant, indicating that P L The constant term in the multivariate linear relationship between shale gas reservoir material composition and percentage.

[0093] Reservoir temperature T r The amount of gas adsorbed by shale gas reservoir Q under the conditions ad The Langmuir adsorption model is:

[0094]

[0095] Among them, Q ad is the adsorbed gas volume of the target shale gas reservoir, and represents the reservoir pressure P r The amount of adsorbed gas under the conditions, in m 3 / t;P r is the reservoir pressure of the target shale gas reservoir, in MPa.

[0096] It should be noted that in the material composition function expression of the Langmuir adsorption model parameters of shale gas reservoirs, the specific clay mineral types and quantities should be determined according to the actual research object. For example, the main clay minerals in the highly evolved Upper Ordovician Wufeng-Lower Silurian Longmaxi Formation shale and Lower Cambrian Niutitang Formation shale in my country are only illite and illite-montmorillonite mixed layers.

[0097] The expression of the Langmuir adsorption model for the amount of gas adsorbed in shale gas reservoirs can be transformed into:

[0098] Q L P r -Q ad P L -Q ad P r =0

[0099] In S104 , the adsorbed gas amount, the Langmuir volume formula, and the Langmuir pressure formula are substituted into the Langmuir adsorption model of the target shale gas reservoir to obtain the Langmuir adsorption model parameters of the target shale gas reservoir.

[0100] In some embodiments of the present application, the Langmuir adsorption model parameters of the target shale gas reservoir are obtained by solving the following steps:

[0101] In S1041, the Langmuir volume formula and the Langmuir pressure formula are substituted into the expression of the Langmuir adsorption model to determine the equation to be solved.

[0102] In S1042, the reservoir parameters, the percentage content of each substance, and the adsorbed gas volume of the target shale gas reservoir are substituted into the equation to be solved, and the equation to be solved is solved to determine the volume coefficient and volume constant in the Langmuir volume formula, and the pressure coefficient and pressure constant in the Langmuir pressure formula.

[0103] In S1043 , the Langmuir adsorption model parameters of the target shale gas reservoir are determined based on the volume coefficient, volume constant, pressure coefficient, pressure constant, and percentage content of each substance.

[0104] Optionally, when determining the Langmuir adsorption model parameters of the target shale gas reservoir, the volume coefficient, volume constant and percentage content of each substance can be substituted into the Langmuir volume formula to determine the Langmuir volume; the pressure coefficient, pressure constant and percentage content of each substance can be substituted into the Langmuir pressure formula to determine the Langmuir pressure.

[0105] In the embodiment of the present application, the Langmuir volume formula and the Langmuir pressure formula are substituted into the function expression after the deformation of the Langmuir adsorption model to obtain the equation to be solved:

[0106]

[0107] Further, let x 2n+1 =P r , x 2n+2 =Q ad , then the above equation to be solved becomes:

[0108]

[0109] Further, let

[0110]

[0111] Then we have:

[0112]

[0113] Where m represents the sample size for constructing the system of equations.

[0114] Here, there are

[0115]

[0116] The above equations can be expressed in matrix form as:

[0117]

[0118] in,

[0119] By solving the above equations or matrix equation model using the least squares method, the volume coefficient k in the Langmuir volume formula can be obtained: i-Q and the volume constant c Q , and the pressure coefficient k in the Langmuir pressure formula i-P and the pressure constant c P .

[0120] Solve for the volume coefficient k i-Q , volume constant c Q , pressure coefficient k i-P and the pressure constant c P After that, it also means that the parameters in the above Langmuir volume formula and Langmuir pressure formula are known. Then, the percentage content of each substance is substituted into the Langmuir volume formula and Langmuir pressure formula to calculate the parameters in the Langmuir adsorption model of the target shale gas reservoir (Langmuir volume Q L and Langmuir pressure P L ).

[0121] In some embodiments of the present application, after determining the volume coefficient, volume constant, pressure coefficient, and pressure constant, the residual sum of squares RSS and the adjusted coefficient of determination adj.R may also be used. 2 The results of the multiple linear regression analysis of the two parameters (i.e., the volume coefficient k i-Q , volume constant c Q , pressure coefficient k i-P and the pressure constant c P ) to conduct error analysis. Here, according to the research needs, the residual sum of squares RSS and the adjusted coefficient of determination adj.R 2 The value must be within the acceptable error range. If it does not reach the acceptable error range, it means that the effect is poor and can be recalculated by increasing the sample size. This application does not impose specific numerical restrictions on the acceptable error range.

[0122] Since the actual value F(x1, x2,…, x i ,…,x 2n+2 ) j =0, so the residual sum of squares RSS calculation formula is:

[0123]

[0124] In the formula, is the fitted value of the j-th observation object, which is also the predicted value.

[0125] The adjusted coefficient of determination adj.R in this application 2 The calculation formula is:

[0126]

[0127] Among them, adj.R 2 and R 2 denote the adjusted and unadjusted coefficients of determination, respectively.

[0128] It should be noted that the smaller the residual sum of squares RSS is, the better the fitting effect is. 2 The larger it is, the better the fitting effect is.

[0129] In one embodiment of the present application, for some terrestrial or marine-continental transitional shale reservoirs with a relatively moderate degree of metamorphism, there are many material components that affect the adsorption of shale, and the Langmuir adsorption model parameter Q L and P L There is a statistical relationship between the content of TOC, kaolinite (K), chlorite (C), illite (I), smectite (S), illite / smectite (I / S) and chlorite / smectite (C / S) and other material components. The function here can usually be expressed linearly as:

[0130] Q L =k TOC-Q ω(TOC)+k K-Q ω(K)+k C-Q ω(C)+k I-Q ω(I)+k S-Q ω(S)+k I / S-Q ω(I / S)

[0131] +k C / S-Q ω(C / S)+c Q

[0132] P L =k TOC-P ω(TOC)+k K-P ω(K)+k C-P ω(C)+k I-P ω(I)+k S-P ω(S)+k I / S-P ω(I / S)

[0133] +k C / S-P ω(C / S)+c P

[0134] In the formula, TOC represents total organic carbon, K represents kaolinite, C represents chlorite, I represents illite, S represents smectite, I / S represents the illite / smectite layer, and C / S represents the chlorite / smectite layer. ω(TOC), ω(K), ω(C), ω(I), ω(S), ω(I / S), and ω(C / S) represent the percentages of total organic carbon, kaolinite, chlorite, illite, smectite, illite / smectite, and chlorite / smectite in the shale gas reservoir, respectively.

[0135] The above parameter Q L and P L Substituting the expression into the deformed function expression of the Langmuir adsorption model, we can get:

[0136] k TOC-Q ω(TOC)P r +k K-Q ω(K)P r +k C-Q ω(C)P r +k I-Q ω(I)P r +k S-Q ω(S)P r

[0137] +k I / S-Q ω(I / S)P r +k C / S-Q ω(C / S)P r -k TOC-P ω(TOC)Q ad -k K-P ω(K)Q ad

[0138] -k C-P ω(C)Q ad -k I-P ω(I)Q ad -k S-P ω(S)Q ad -k I / S-P ω(I / S)Q ad

[0139] -k C / S-P ω(C / S)Q ad +c Q P r -c P Q ad -Q ad P r

[0140] =0

[0141] Perform the following substitutions:

[0142] x 15 =P r ,x 16 =Q ad

[0143] k TOC-Q x1 + k K-Q x2 + k C-Q x3 + k I-Q x4 + k S-Q x5 + k I / S-Q x6 + k C / S-Q x7 - k TOC-P x8 - k K-P x9 - k C-P x 10 -k I-P x 11 -k S-P x 12 -k I / S-P x 13 -k C / S-P x 14 +c Q x 15 -c P x 16 -x 15 x 16 =0

[0144] Let

[0145] F(x1,x2,x3,x4,x5,x6,x7,x8,x9,x 10 ,x 11 ,x 12 ,x 13 ,x 14 ,x 15 ,x 16 )

[0146] =k TOC-Q x1 + k K-Q x2 + k C-Q x3 + k I-Q x4 + k S-Q x5 + k I / S-Q x6 + k C / S-Q x7 - k TOC-P x8

[0147] -k K-P x9 - k C-P x 10 -k I-P x 11 -k S-P x 12 -k I / S-Px 13 -k C / S-P x 14 +c Q x 15 -c P x 16 -x 15 x 16

[0148]

[0149] Here

[0150] F(x1,x2,x3,x4,x5,x6,x7,x8,x9,x 10 ,x 11 ,x 12 ,x 13 ,x 14 ,x 15 ,x 16 ) j

[0151] =k TOC-Q x 1,j +k K-Q x 2,j +k C-Q x 3,j +k I-Q x 4,j +k S-Q x 5,j +k I / S-Q x 6,j +k C / S-Q x 7,j

[0152] -k TOC-P x 8,j -k K-P x 9,j -k C-P x 10,j -k I-P x 11,j -k S-P x 12,j -k I / S-P x 13,j -k C / S-P x 14,j

[0153] +c Q x 15,j -c P x 16,j -x 15,j x 16,j

[0154] Let

[0155]

[0156] The above equations can be rewritten in matrix form as:

[0157] k TOC-Q X1+k K-Q X2+k C-Q X3+k I-Q X4+k S-Q X5+k I / S-Q X6+k C / S-Q X7

[0158] -k TOC-P X8-k K-P X9-k C-P X 10 -k I-P X 11 -k S-P X 12 -k I / S-P X 13 -k C / S-P X 14

[0159] +c Q X 15 -c P X 16 -x 15 X 16 =O

[0160] Determine k by solving the system of equations or multivariate linear regression analysis TOC-Q 、k K-Q 、k C-Q 、k I-Q 、k S-Q 、k I / S-Q 、k C / S-Q 、k TOC-P 、k K-P 、k C-P 、k I-P 、k S-P 、k I / S-P 、k C / S-P 、c Q and c P Afterwards, the Langmuir adsorption model parameters of the target shale sample can be further calculated.

[0161] In particular, for some shales, the substance that affects the adsorption of the reservoir is mainly organic matter, especially for marine shales, this situation is more common. Usually, the Langmuir adsorption model parameter Q L and P L There was a significant linear correlation between the TOC content and the

[0162]

[0163] The above parameter Q L and P L Substituting the expression into the deformed function expression of the Langmuir adsorption model, we can get:

[0164] P r k TOC-Q ω(TOC)-Q ad k TOC-P ω(TOC)+c Q P r -c P Q ad -Q ad P r =0

[0165] Substitute the parameters in the above equations,

[0166]

[0167] Then the equation can be transformed into:

[0168] k TOC-Q x1-k TOC-P x2+c Q x3-c P x4-x3x4=0

[0169] The equations constructed for shale samples with a sample size of m are:

[0170]

[0171] The variables are represented by a matrix:

[0172]

[0173] The matrix expression of the equation system is:

[0174] k TOC-Q X1-k TOC-P X2+c Q X3-c P X4-X3X4=O

[0175] Determine k by solving the system of equations or multivariate linear regression analysis TOC-Q 、k TOC-P 、c Q and c P Afterwards, the Langmuir adsorption model parameters of the shale sample to be evaluated can be further calculated.

[0176] The Langmuir adsorption model determination method for shale gas reservoirs provided in this application can achieve the following effects:

[0177] (1) This application takes into account the Langmuir adsorption model parameter Q of shale gas reservoirs L and P L The intrinsic connection between the adsorption components of the shale reservoir and the adsorption of the shale reservoir is established, and the statistical relationship expression between the two is fully utilized as a medium to determine the Langmuir adsorption model parameters. This can avoid the isothermal adsorption experimental analysis with strict sample specification restrictions, high costs, long time periods and high instrument requirements. A large number of adsorption model parameters can be calculated in a short time, and the shale reservoir and gas content information can be obtained at the same time.

[0178] (2) This application takes into account the material components that affect the adsorption of shale reservoirs. By analyzing the types and contents of the adsorbed components of shale reservoirs and combining the relationship between the adsorbed gas volume and the adsorbed components, a set of equations can be constructed to further determine the parameters of the Langmuir adsorption model. During the operation of the method, the specific actual situation is also considered as a constraint condition, thereby improving the scientific effectiveness of the method.

[0179] (3) This application can not only determine the Langmuir adsorption model parameter Q of the shale sample to be evaluated L and P L , and can clarify the statistical quantitative relationship between adsorption model parameters and shale adsorption components, further providing a basis for studying the main controlling factors and control mechanisms of shale reservoir adsorption.

[0180] (4) This application can not only obtain the gas-bearing parameters of shale reservoirs, but also contribute to the understanding of shale gas geological laws and the establishment of geological models, and further provide important reference for the refined deployment of shale gas exploration and development.

[0181] (5) This application can not only be directly applied to shale gas reservoirs, but also has inspiring significance and promotion value for obtaining Langmuir adsorption model parameters of other black rock reservoirs with adsorptive properties (such as coalbed methane reservoirs and tight carbonate reservoirs).

[0182] (6) The reservoir parameters and gas content parameters involved in this application are all quantifiable, which makes the method of the present invention have the basis and conditions for digitalization, informatization, automation and intelligence, and thus makes the method easy to operate and very conducive to promotion and application.

[0183] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0184] Corresponding to the method for determining the Langmuir adsorption model of shale gas reservoirs described in the above embodiment, Figure 2 A structural block diagram of a device for determining a Langmuir adsorption model of a shale gas reservoir provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0185] See also Figure 2 The device for determining the Langmuir adsorption model of a shale gas reservoir in the embodiment of the present application may include an acquisition module 201 , a calculation module 202 , a construction module 203 and a solution module 204 .

[0186] The acquisition module 201 is used to obtain the reservoir parameters and percentage content of each substance of the target shale gas reservoir.

[0187] The calculation module 202 is used to determine the adsorbed gas volume of the target shale gas reservoir according to the reservoir parameters.

[0188] Construction module 203 is used to establish the Langmuir volume formula and the Langmuir pressure formula according to the percentage content of each substance. The Langmuir volume formula is a statistical relationship function between the Langmuir volume and the percentage content of each substance. The Langmuir pressure formula is a statistical relationship function between the Langmuir pressure and the percentage content of each substance.

[0189] The solving module 204 is used to substitute the adsorbed gas amount, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir to solve and obtain the Langmuir adsorption model parameters of the target shale gas reservoir.

[0190] Optionally, the calculation module 202 is specifically used to: obtain the gas saturation and total gas content of the target shale gas reservoir; determine the free gas content of the target shale gas reservoir based on the reservoir parameters and the gas saturation of the target shale gas reservoir; and determine the adsorbed gas content of the target shale gas reservoir by subtracting the free gas content of the target shale gas reservoir from the total gas content of the target shale gas reservoir.

[0191] Optionally, the reservoir parameters include porosity, reservoir pressure, apparent density and reservoir temperature of the target shale gas reservoir.

[0192] The calculation module 202 is specifically used to: Calculate the free gas volume of the target shale gas reservoir; where Q fr is the free gas volume of the target shale gas reservoir; Z0 and Z r are the shale gas compressibility factors under standard conditions and reservoir conditions, respectively; S g is the gas saturation of the target shale gas reservoir; is the porosity of the target shale gas reservoir; T0 is the gas thermodynamic temperature under standard conditions, T0 = 273.15K; P r is the reservoir pressure of the target shale gas reservoir; ρ b is the apparent density of the target shale gas reservoir; T r is the reservoir temperature of the target shale gas reservoir; P0 is the reservoir pressure under standard conditions, P0 = 0.101325 MPa.

[0193] Alternatively, the Langmuir volume formula is:

[0194]

[0195] Among them, Q L is the Langmuir volume; k i-Q is the volume coefficient; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; c Q is the volume constant.

[0196] The Langmuir pressure formula is:

[0197]

[0198] Among them, P L is the Langmuir pressure; k i-P is the pressure coefficient; c P is the pressure constant.

[0199] The Langmuir adsorption model is:

[0200]

[0201] Among them, Q ad is the adsorbed gas volume of the target shale gas reservoir; P r is the reservoir pressure of the target shale gas reservoir.

[0202] Optionally, the solution module 204 is specifically used to: substitute the Langmuir volume formula and the Langmuir pressure formula into the expression of the Langmuir adsorption model to determine the equation to be solved; substitute the reservoir parameters, the percentage content of each substance and the adsorbed gas volume of the target shale gas reservoir into the equation to be solved, and solve the equation to be solved to determine the volume coefficient and volume constant in the Langmuir volume formula, and the pressure coefficient and pressure constant in the Langmuir pressure formula; wherein the volume coefficient is the coefficient of each substance component in the Langmuir volume formula; the volume constant is the constant term in the Langmuir volume formula; the pressure coefficient is the coefficient of each substance component in the Langmuir pressure formula; the pressure constant is the constant term in the Langmuir pressure formula; based on the volume coefficient, volume constant, pressure coefficient, pressure constant and the percentage content of each substance, determine the Langmuir adsorption model parameters of the target shale gas reservoir.

[0203] Optionally, the equation to be solved is:

[0204]

[0205] Among them, P r is the reservoir pressure of the target shale gas reservoir; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; Q ad is the adsorbed gas volume of the target shale gas reservoir; k i-Q is the volume coefficient; k i-P is the pressure coefficient; c Q is the volume constant; c P is the pressure constant.

[0206] Optionally, the Langmuir adsorption model parameters of the target shale gas reservoir include Langmuir volume and Langmuir pressure.

[0207] The solution module 204 is specifically used to: substitute the volume coefficient, volume constant and percentage of each substance into the Langmuir volume formula to determine the Langmuir volume; substitute the pressure coefficient, pressure constant and percentage of each substance into the Langmuir pressure formula to determine the Langmuir pressure.

[0208] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of this application. Their specific functions and technical effects can be found in the method embodiment section and will not be repeated here.

[0209] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0210] The present application also provides an electronic device. Figure 3 The electronic device 300 may include: at least one processor 310, a memory 320, and a computer program stored in the memory 320 and executable on the at least one processor 310. When the processor 310 executes the computer program, the steps in any of the above-mentioned method embodiments are implemented, for example Figure 1 Alternatively, when the processor 310 executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 2 Functions of modules 201 to 204 are shown.

[0211] For example, the computer program may be divided into one or more modules / units, one or more modules / units being stored in the memory 320 and executed by the processor 310 to complete the present application. The one or more modules / units may be a series of computer program segments capable of completing specific functions, and the program segments are used to describe the execution process of the computer program in the electronic device 300.

[0212] Those skilled in the art will understand that Figure 3 These are merely examples of electronic devices and do not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or a combination of certain components, or different components, such as input and output devices, network access devices, buses, etc.

[0213] The processor 310 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0214] The memory 320 can be an internal storage unit of the electronic device or an external storage device of the electronic device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. The memory 320 is used to store the computer program and other programs and data required by the electronic device. The memory 320 can also be used to temporarily store data that has been output or is about to be output.

[0215] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be classified into address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0216] The method for determining the Langmuir adsorption model of a shale gas reservoir provided in the embodiments of the present application can be applied to electronic devices such as computers, tablet computers, laptop computers, netbooks, personal digital assistants (PDAs), augmented reality (AR) / virtual reality (VR) devices, and mobile phones. The embodiments of the present application do not impose any restrictions on the specific types of electronic devices.

[0217] An embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the steps in each embodiment of the above-mentioned method for determining the Langmuir adsorption model of a shale gas reservoir can be implemented.

[0218] An embodiment of the present application provides a computer program product. When the computer program product is run on a mobile electronic device, the mobile electronic device can implement the steps in each embodiment of the above-mentioned method for determining the Langmuir adsorption model of a shale gas reservoir.

[0219] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the camera / electronic device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunications signal and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk.

[0220] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0221] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0222] In the embodiments provided in this application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0223] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0224] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for determining a Langmuir adsorption model of a shale gas reservoir, characterized in that: include: Obtaining reservoir parameters and percentage content of each substance of the target shale gas reservoir; Determining the amount of adsorbed gas in the target shale gas reservoir according to the reservoir parameters; According to the percentage content of each substance, a Langmuir volume formula and a Langmuir pressure formula are established respectively; wherein the Langmuir volume formula is a statistical relationship function between the Langmuir volume and the percentage content of each substance; and the Langmuir pressure formula is a statistical relationship function between the Langmuir pressure and the percentage content of each substance; Substituting the adsorbed gas amount, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir, and solving to obtain the Langmuir adsorption model parameters of the target shale gas reservoir; Determining the amount of adsorbed gas in the target shale gas reservoir according to the reservoir parameters includes: Obtaining the gas saturation and total gas content of the target shale gas reservoir; Determining the free gas volume of the target shale gas reservoir according to the reservoir parameters and the gas saturation of the target shale gas reservoir; Determine the adsorbed gas content of the target shale gas reservoir by subtracting the free gas content of the target shale gas reservoir from the total gas content of the target shale gas reservoir; The reservoir parameters include porosity, reservoir pressure, apparent density and reservoir temperature of the target shale gas reservoir; The Langmuir volume formula is: Among them, Q L is the Langmuir volume; k i-Q is the volume coefficient; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; c Q is the volume constant; The Langmuir pressure formula is: Among them, P L is the Langmuir pressure; k i-P is the pressure coefficient; c P is the pressure constant; The Langmuir adsorption model is: Among them, Q ad is the adsorbed gas volume of the target shale gas reservoir; r is the reservoir pressure of the target shale gas reservoir.

2. The method for determining the Langmuir adsorption model of a shale gas reservoir according to claim 1, characterized in that: Determining the free gas volume of the target shale gas reservoir according to the reservoir parameters and the gas saturation of the target shale gas reservoir includes: pass Calculating the free gas volume of the target shale gas reservoir; Among them, Q fr is the free gas volume of the target shale gas reservoir; Z0 and Z r are the shale gas compression factors under standard conditions and reservoir conditions, respectively; S g is the gas saturation of the target shale gas reservoir; is the porosity of the target shale gas reservoir; T0 is the thermodynamic temperature of gas under standard conditions, T0 = 273.15 K; P r is the reservoir pressure of the target shale gas reservoir; ρ b is the apparent density of the target shale gas reservoir; T r is the reservoir temperature of the target shale gas reservoir; P0 is the reservoir pressure under standard conditions, P0 = 0.101325 MPa.

3. The method for determining the Langmuir adsorption model of a shale gas reservoir according to claim 1, wherein: Substituting the adsorbed gas volume, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir to obtain the Langmuir adsorption model parameters of the target shale gas reservoir includes: Substituting the Langmuir volume formula and the Langmuir pressure formula into the expression of the Langmuir adsorption model to determine the equation to be solved; Substituting the reservoir parameters, the percentage content of each substance and the adsorbed gas volume of the target shale gas reservoir into the equation to be solved, and solving the equation to be solved, determining the volume coefficient and volume constant in the Langmuir volume formula, and the pressure coefficient and pressure constant in the Langmuir pressure formula; wherein the volume coefficient is the coefficient of each substance component in the Langmuir volume formula; the volume constant is the constant term in the Langmuir volume formula; the pressure coefficient is the coefficient of each substance component in the Langmuir pressure formula; and the pressure constant is the constant term in the Langmuir pressure formula; Based on the volume coefficient, the volume constant, the pressure coefficient, the pressure constant and the percentage content of each substance, the Langmuir adsorption model parameters of the target shale gas reservoir are determined.

4. The method for determining the Langmuir adsorption model of a shale gas reservoir according to claim 3, characterized in that: The equation to be solved is: Among them, P r is the reservoir pressure of the target shale gas reservoir; i is the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; Q ad k is the adsorbed gas volume of the target shale gas reservoir; i-Q is the volume coefficient; k i-P is the pressure coefficient; c Q is the volume constant; c P is the pressure constant.

5. The method for determining the Langmuir adsorption model of a shale gas reservoir according to claim 3, characterized in that: The Langmuir adsorption model parameters of the target shale gas reservoir include the Langmuir volume and the Langmuir pressure; Determining the Langmuir adsorption model parameters of the target shale gas reservoir based on the volume coefficient, the volume constant, the pressure coefficient, the pressure constant and the percentage content of each substance includes: Substituting the volume coefficient, the volume constant and the percentage content of each substance into the Langmuir volume formula to determine the Langmuir volume; The pressure coefficient, the pressure constant and the percentage content of each substance are substituted into the Langmuir pressure formula to determine the Langmuir pressure.

6. A device for determining Langmuir adsorption model of shale gas reservoir, characterized in that: include: An acquisition module, used to obtain reservoir parameters and percentage content of each substance of a target shale gas reservoir; A calculation module, used to determine the adsorbed gas volume of the target shale gas reservoir according to the reservoir parameters; A construction module is used to establish a Langmuir volume formula and a Langmuir pressure formula according to the percentage content of each substance; wherein the Langmuir volume formula is a statistical relationship function between the Langmuir volume and the percentage content of each substance; and the Langmuir pressure formula is a statistical relationship function between the Langmuir pressure and the percentage content of each substance; A solution module, used for substituting the adsorbed gas amount, the Langmuir volume formula and the Langmuir pressure formula into the Langmuir adsorption model of the target shale gas reservoir to solve and obtain the Langmuir adsorption model parameters of the target shale gas reservoir; The calculation module is specifically used for: Obtaining the gas saturation and total gas content of the target shale gas reservoir; Determining the free gas volume of the target shale gas reservoir according to the reservoir parameters and the gas saturation of the target shale gas reservoir; Determine the adsorbed gas content of the target shale gas reservoir by subtracting the free gas content of the target shale gas reservoir from the total gas content of the target shale gas reservoir; The reservoir parameters include porosity, reservoir pressure, apparent density and reservoir temperature of the target shale gas reservoir; The Langmuir volume formula is: Among them, Q L is the Langmuir volume; k i-Q is the volume coefficient; i represents the i-th material component related to adsorption in the target shale gas reservoir, n is the number of material components related to adsorption in the target shale gas reservoir, ω(i) is the percentage content of the i-th material component; c Q is the volume constant; The Langmuir pressure formula is: Among them, P L is the Langmuir pressure; k i-P is the pressure coefficient; c P is the pressure constant; The Langmuir adsorption model is: Among them, Q ad is the adsorbed gas volume of the target shale gas reservoir; r is the reservoir pressure of the target shale gas reservoir.

7. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

Images