Calculation method and system applied to sea-land transition phase shale gas resource quantity

Abstract

The invention discloses a calculation method and system applied to a sea-land transition phase shale gas resource quantity. The method comprises the following steps: collecting logging data of each well location in a target work area; collecting a shale sample, and testing the gas content of the sample by using an on-site desorption method; well logging curves sensitive to the gas content are extracted respectively, and a calculation model of the gas content and the extracted well logging curves is established; calculating gas content predicted values of multiple well positions in the target work area according to the calculation model; drawing a work area gas content contour map according to the gas content average value of each well position, and dividing a single well control area according to a contour line; and single well shale gas resource quantity is calculated, and superposition is carried out to calculate the shale gas resource quantity of the sea-land transition phase work area of the target work area. According to the method, the target work area sea-land transition phase shale gas resource quantity can be quickly and accurately calculated based on rich logging parameters, a reliable basis is provided for target work area sea-land transition phase resource evaluation, and the method has high operability and applicability.

Description

Technical Field

[0001] The present invention relates to the technical field of geological exploration, and particularly relates to a calculation method and system for the resource volume of shale gas in the transitional facies between sea and land. Background Art

[0004] FORSPAN is an evaluation method for predicting the resource volume with potential for reserve increase in the future using the known resource volume in the evaluation area. It was proposed by the USGS in 1999 for continuous oil and gas reservoirs such as shale gas. In 2003 and 2007, the USGS used this method to conduct shale gas resource evaluations on the Barnett Shale successively, and the evaluation results were 0.74×1012 m3 and 2.66×1012 m3 respectively (Richard M. Pollastro, 2007).

[0005] The single-well reserve estimation method was proposed by ARI in 2006 for estimating the shale gas resource volume in 48 states of the United States. It is a method that regards the well-controlled area of one well as the smallest evaluation unit for reserve prediction and then accumulates to obtain the total resource volume. Using this method, the recoverable resource volume in 48 states was obtained as 3.97×1012 m3. In 2011, EIA used this method to estimate the resources of 19 shale formations in the United States, and the evaluation result was 21.25×1012 m3.

[0006] The concept of production decline was first proposed by R. Arnold and R. Anderson (Arnold et al., 1908). After years of improvement and application, in 1945, Arps proposed three decline equations, namely exponential decline, hyperbolic decline, and harmonic decline, based on a large amount of production data statistics and analysis; in 2009, Valko conducted targeted research on the decline method of shale gas production and proposed the extended exponential decline method; in 2010, Duong made improvements for fractured shale gas reservoirs and proposed the empirical analysis method of production decline. In 1936, R. J. Schilthuis first proposed the material balance equation based on the dynamic analysis of gas reservoirs; in 1964, Coast et al. first proposed an improved function for the influence of water invasion on the balance equation; in 1990, King G. R. et al. used the principle of constant volume to establish a corresponding balance equation through the potential relationship between formation pressure and cumulative production in shale gas production, and calculated the shale gas resource volume.

[0007] The volume method has relatively high accuracy and is widely used in static evaluation methods based on geological parameters. In 1993, Decker used this method to estimate the resource abundance of shale gas in the Norwood and Lachine sections of the Antrim Shale, and the estimation result was 0.78×108 m3.

[0009] The analogy method is widely used in areas with low shale gas exploration and development levels and limited relevant data. Zhu Hua et al. (2009) used the resource abundance analogy method with the Fort Worth Barnett Shale as the analog object to evaluate the shale gas resources in the Western Sichuan Depression, estimating the total shale gas resources in the Xuwu Formation of the Western Sichuan Depression to be 2.26×10¹² m³; Jia Chengzao et al. (2012) referred to the measured shale gas resource abundances in the United States and the Weiyuan area of Sichuan, and used the resource abundance analogy method to preliminarily evaluate the shale gas resources in the country, believing that the geological shale gas resources in China are (86 - 166)×10¹² m³, and the recoverable resources are (15 - 25)×10¹² m³; Shi Chuang et al. (2015) used the volume abundance analogy method to estimate the shale gas resources in the Wufeng-Longmaxi Formation in Hubei and its periphery, selecting the Ohio Shale in the Appalachian Basin as the analog calibration area, and estimating the total resources to be 2.48×10¹² m³; Guo Shizhao et al. (2016) used the area abundance analogy method with the Fort Worth Barnett Shale as the standard area to estimate the resources in the Longmaxi Formation in the northern Guizhou area, obtaining a geological shale gas resource of (3.52 - 4.69)×10¹² m³.

[0010] The genetic method is also widely used. Zhang Jinchuan et al. (2008) used it as one of the main methods during the national shale gas resource evaluation; Wang Xiangzeng et al. (2012) used this method to estimate the resources in the Chang 7 Member of the Upper Triassic Yanchang Formation in the Zhongzhi-Lower Siwan areas of the Yanchang Oil Region to be (3297 - 5531.62)×10⁸ m³; Zhu Hua et al. (2009) used the genetic method to calculate the total shale gas resources in the Xuwu Formation of the Western Sichuan Depression to be 1.49×10¹² m³.

[0011] The statistical method is the most widely used method in China at present (Zhang Jinchuan et al., 2008; Dong Dazhong et al., 2009; Li Yanjun et al., 2011; Li Yuxi et al., 2011). Considering the particularity of shale gas resource evaluation in China and the data characteristics, Zhang Jinchuan et al. (2012) established the probability volume method on this basis. This method is the method with relatively the highest accuracy at the present stage in China and has been widely used (Han Shuangbiao et al., 2013; Xiong Zhuang et al., 2014; Li Guoliang et al., 2015; Zhao Yong et al., 2015; Guo Shizhao et al., 2016). The Oil and Gas Resources Strategic Research Center of the Ministry of Land and Resources used this method as the main method for resource evaluation work in the national shale gas resource evaluation in 2011 and the subsequent dynamic resource evaluation in 2015.

[0012] Although the research on shale gas resource calculation methods has tended to be mature, most of them are based on calculating the resources of marine shale or continental shale. In view of the scarcity of shale gas resource evaluation work for marine-continental transitional shale at home and abroad and the strong heterogeneity of marine-continental transitional shale, there are relatively large errors in the calculation results of the current methods.

[0013] Therefore, in order to more accurately evaluate the resources of marine - continental transitional shale, there is an urgent need for a new method to calculate the shale gas resources of marine - continental transitional shale. This method can calculate the average gas content of each well position based on logging data, then calculate the single - well resource volume, and finally superimpose them to obtain the shale gas resource volume of the work area, in order to reduce the error caused by the heterogeneity of marine - continental transitional shale. Summary of the Invention

[0014] In view of the above problems, the present invention is proposed to provide a calculation method and system for shale gas resources in marine - continental transitional shale, which can overcome the above problems or at least partially solve the above problems.

[0015] In the first aspect, a calculation method for shale gas resources in marine - continental transitional shale is provided. The calculation method for shale gas resources in marine - continental transitional shale includes:

[0016] S1. Select a target work area, collect logging data in the target work area and formation basic characteristic data of the target horizon. The formation basic characteristic data includes the single - well shale thickness and the single - well shale density;

[0017] S2. Collect shale samples, collect their basic data, and use the desorption method to calculate the gas content of the collected downhole shale samples;

[0018] S3. Extract logging curves sensitive to gas content respectively. The logging curves include the acoustic travel - time curve, the natural gamma curve, the compensated neutron curve, and the density curve;

[0019] S4. Establish a calculation model between gas content and the extracted logging curves. The calculation model is a multiple regression equation based on the logging curves;

[0020] S5. Calculate the predicted gas content values corresponding to each well position in the work area through the calculation model, and take the average single - well gas content in the work area. The average single - well gas content is the average value of the predicted gas content values calculated for each well position in the work area;

[0021] S6. Select a new well position and obtain the measured gas content value corresponding to it, and calculate the predicted gas content value of the new well position through the calculation model. Fit the obtained measured gas content value with the predicted gas content value calculated by the calculation model to verify the applicability of the calculation model to the new well position;

[0022] S7. After the applicability of the calculation model is verified, draw a gas - content contour map of the work area based on the predicted gas content values calculated for each well position, and divide the single - well controlled area through the gas - content contour;

[0023] S8. Calculate the shale gas resource volume corresponding to each well position by the average gas content per well, the controlled area per well, the shale thickness per well, and the shale density per well, and finally obtain the shale gas resource volume of the work area by superposition.

[0024] Optionally, in step S4, the specific multiple regression equation included in the calculation model is:

[0025] V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253

[0026] In the formula, V is the predicted gas content value, with the unit m 3 / t; AC is the acoustic travel time, with the unit μs / m; GR is the natural gamma ray, with the unit API; CNL is the compensated neutron, with the unit %; DEN is the density, with the unit g / cm 3 .

[0027] Optionally, in step S5, the average gas content per well is calculated and obtained through the following formula:

[0028]

[0029] In the formula, V m is the average gas content per well, n is the number of well positions in the work area, and n is a positive integer.

[0030] Optionally, in step S8, the calculation of the shale gas resource volume corresponding to each well position by the average gas content per well, the controlled area per well, the shale thickness per well, and the shale density per well is specifically calculated and obtained through the following formula:

[0031] Q m = 0.01×S×H×ρ×V m

[0032] In the formula, V m is the average gas content per well, S is the controlled area per well, H is the shale thickness per well, ρ is the shale density per well, and Q m is the shale gas resource volume corresponding to the mth well position, m is a positive integer and m ≤ n.

[0033] Optionally, in step S8, the calculation of obtaining the shale gas resource volume of the work area by superposition is calculated and obtained through the following formula:

[0034]

[0035] In the formula, Q is the shale gas resource volume of the work area obtained by superposition corresponding to m well positions.

[0036] Second aspect, the present invention provides a calculation system for shale gas resources in the marine - continental transitional facies. The calculation system for shale gas resources in the marine - continental transitional facies includes:

[0037] A data acquisition module, configured to select a target work area, collect logging data in the target work area and formation basic characteristic data of the target horizon, where the formation basic characteristic data includes the shale thickness of a single well and the shale density of a single well;

[0038] A sample collection module, configured to collect shale samples, collect their basic data, and calculate the gas content of the collected downhole shale samples by using the desorption method;

[0039] A logging curve extraction module, configured to extract logging curves sensitive to gas content respectively, where the logging curves include the acoustic travel - time curve, the natural gamma curve, the compensated neutron curve, and the density curve;

[0040] A gas content calculation module, configured to establish a calculation model between the gas content and the extracted logging curves, and the calculation model is a multiple regression equation based on the logging curves;

[0041] A gas content average value calculation module, configured to calculate the predicted gas content values corresponding to each well position in the work area through the calculation model, and take the average value of the single - well gas content in the work area, where the average value of the single - well gas content is the average of the predicted gas content values calculated for each well position in the work area;

[0042] A verification module, configured to select a new well position and obtain the measured gas content value corresponding thereto, and calculate the predicted gas content value of the new well position through the calculation model, and fit the obtained measured gas content value with the predicted gas content value calculated by the calculation model to verify the applicability of the calculation model to the new well position;

[0043] A drawing module, configured to, after the applicability of the calculation model is verified, draw a gas content isogram of the work area according to the predicted gas content values calculated for each well position, and divide the single - well control area through the gas content isogram;

[0044] A shale gas resource quantity calculation module, configured to calculate the single - well shale gas resource quantity corresponding to each well position through the average value of the single - well gas content, the single - well control area, the shale thickness of a single well, and the shale density of a single well, and finally obtain the shale gas resource quantity of the work area by superposition.

[0045] Optionally, the multiple regression equation included in the calculation model established by the gas content calculation module is specifically:

[0046] V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253

[0047] Wherein, V is the predicted gas content value, with the unit of m 3 / t; AC is the acoustic time difference, with the unit of μs / m; GR is the natural gamma ray, with the unit of API; CNL is the compensated neutron, with the unit of %; DEN is the density, with the unit of g / cm 3 .

[0048] Optionally, the average gas content calculation module calculates the average gas content of a single well through the following formula:

[0049]

[0050] Wherein, V m is the average gas content of a single well, n is the number of well positions in the work area, and n is a positive integer.

[0051] Optionally, the shale gas resource calculation module calculates the shale gas resource of each well position through the average gas content of a single well, the controlled area of a single well, the shale thickness of a single well, and the shale density of a single well, and specifically obtains it through the following formula:

[0052] Q m = 0.01×S×H×ρ×V m

[0053] Wherein, V m is the average gas content of a single well, S is the controlled area of a single well, H is the shale thickness of a single well, ρ is the shale density of a single well, and Q m is the shale gas resource of the m-th well position, m is a positive integer and m ≤ n.

[0054] Optionally, the shale gas resource calculation module obtains the shale gas resource of the work area by superposition, and obtains it through the following formula:

[0055]

[0056] Wherein, Q is the shale gas resource of the work area obtained by superposition of m well positions.

[0057] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0058] A calculation method and system for the shale gas resource volume in the marine - continental transitional facies provided by the embodiments of the present invention. The calculation method for the shale gas resource volume in the marine - continental transitional facies can quickly and accurately calculate the shale gas resource volume in the target work area based on rich logging parameters, providing a reliable basis for the resource evaluation of the marine - continental transitional facies in the target work area, having high operability and applicability, and solving the problems in the prior art such as the need to test the gas content data of samples using the in - situ desorption method, where the experiment must be carried out when the samples are just taken out of the well, as well as the high cost of drilling and limited samples. At the same time, the embodiments of the present invention calculate the shale gas resource volume in the marine - continental transitional facies by dividing the work area into small units according to well positions, then calculating the resource volume of the small units controlled by a single well, and finally calculating the resource volume of the work area by superposition, which can better reduce the error caused by shale heterogeneity and has good applicability.

[0059] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following specifically describes the embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0061] In the drawings:

[0062] Figure 1 is a schematic flow chart of the calculation method for the shale gas resource volume in the marine - continental transitional facies described in the embodiments of the present invention;

[0063] Figure 2 is a reference schematic diagram of the correlation curve between the measured gas content value and the predicted gas content value;

[0064] Figure 3 is a reference schematic diagram of the curve for verifying the predicted gas content value with the measured gas content value;

[0065] Figure 4 is a reference schematic diagram of the gas content isogram in the work area;

[0066] Figure 5 is a reference schematic diagram of the resource abundance isogram in the work area;

[0067] Figure 6 is a schematic principle structure diagram of the calculation system for the shale gas resource volume in the marine - continental transitional facies described in the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0068] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0069] Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art can additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0070] To better understand the above technical solutions, the above technical solutions will be described in detail below in combination with specific embodiments. It should be understood that the embodiments of the present disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, rather than limitations on the technical solutions of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0071] Figure 1 is a schematic flowchart of a calculation method for shale gas resources in transitional marine and continental facies provided by an embodiment of the present invention. As Figure 1 shown, the calculation method for shale gas resources in transitional marine and continental facies includes:

[0072] S1. Select a target work area, collect well logging data in the target work area and formation basic characteristic data of the target horizon, where the formation basic characteristic data includes basic data such as single-well shale thickness and single-well shale density;

[0073] S2. Collect shale samples, collect their basic data, and use the desorption method for the collected downhole shale samples to calculate their gas content; Refer to Figure 2 shown, it is a reference schematic diagram of the correlation curve between the measured gas content value and the predicted gas content value.

[0074] S3. Extract well logging curves sensitive to gas content respectively, where the well logging curves include acoustic time difference curve, natural gamma curve, compensated neutron curve, and density curve;

[0075] S4. Establish a calculation model between gas content and the extracted well logging curves, where the calculation model is a multiple regression equation based on the well logging curves; In the embodiment of the present invention, optionally, in step S4, the multiple regression equation included in the calculation model is specifically:

[0076] V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253

[0077] For example, the coefficient of determination can be R 2 = 0.85;

[0078] In the formula, V is the predicted gas content value, with the unit of m 3 / t; AC is the acoustic time difference, with the unit of μs / m; GR is the natural gamma ray, with the unit of API; CNL is the compensated neutron, with the unit of %; DEN is the density, with the unit of g / cm 3 .

[0079] S5. Calculate the predicted gas content values corresponding to each well position in the work area through the calculation model, and take the average single-well gas content of each well position in the work area. The average single-well gas content is the average value of the predicted gas content values obtained by calculating each well position in the work area; Optionally, in step S5, the average single-well gas content is calculated through the following formula:

[0080]

[0081] In the formula, V m is the average single-well gas content, n is the number of well positions in the work area, and n is a positive integer.

[0082] S6. Select a new well position and obtain the corresponding measured gas content value, and calculate the predicted gas content value of the new well position through the calculation model. Fit the obtained measured gas content value with the predicted gas content value calculated by the calculation model to verify the applicability of the calculation model to the new well position; For example, select the new well DJ3-4, fit its measured gas content value and the model calculation result to verify the model applicability. Refer to Figure 3 as shown Figure 3 is a curve reference schematic diagram for verifying the predicted gas content value with the measured gas content value.

[0083] S7. After the applicability of the calculation model is verified, draw a gas content isogram of the work area based on the predicted gas content values calculated for each well position, and divide the single-well control area through the gas content isogram; Refer to Figure 4 as shown Figure 4 is a reference schematic diagram of the gas content isogram of the work area.

[0084] S8. Calculate the single-well shale gas resource amount corresponding to each well position through the average single-well gas content, single-well control area, single-well shale thickness, and single-well shale density, and finally obtain the shale gas resource amount of the work area by superposition.

[0085] Optionally, in step S8, the calculation of the single-well shale gas resource amount corresponding to each well position through the average single-well gas content, single-well control area, single-well shale thickness, and single-well shale density is specifically calculated through the following formula:

[0086] Qm = 0.01 × S × H × ρ × V m

[0087] Wherein, V m is the average gas content per well, S is the controlled area per well, H is the shale thickness per well, ρ is the shale density per well, and Q m is the shale gas resource amount per well corresponding to the m-th well position, m is a positive integer and m ≤ n. For example, in the embodiments of the present invention, the values of m and n are the same. In other embodiments, m can also be selected as other values, which can be selected according to actual needs, and the embodiments of the present invention have no limitation in this regard.

[0088] Optionally, in step S8, the shale gas resource amount of the work area obtained by superposition is calculated by the following formula:

[0089]

[0090] Wherein, Q is the shale gas resource amount of the work area obtained by superposition corresponding to m well positions. When the values of m and n are the same, what is obtained is the total shale gas resource amount of all n well positions in the work area.

[0091] Table 1

[0092] Region <![CDATA[Resource quantity × 10 8 m 3 > <![CDATA[Resource abundance × 10 8 m 3 / km 2 > Work Area A 9339.54 1.70

[0093] Referring to Table 1 and Figure 5 as shown, Table 1 is the reference data of the shale gas resource amount and resource abundance of the work area, Figure 5 is the reference schematic diagram of the resource abundance isogram of the work area. In the embodiments of the present invention, the shale gas resource amount Q corresponding to the m-th well position is calculated through the average gas content per well V m , the controlled area per well S, the shale thickness per well H, and the shale density per well ρ, m , and finally the shale gas resource amount Q of the work area is obtained by superposition.

[0094] The calculation method for the shale gas resource amount in the marine-continental transitional facies applied in the embodiments of the present invention has the following advantages compared with the prior art:

[0095] 1. Based on rich logging parameters, the embodiments of the present invention can quickly and accurately calculate the shale gas resource amount in the marine-continental transitional facies of the target work area, providing a reliable basis for the resource evaluation of the marine-continental transitional facies of the target work area, with high operability and applicability, and solving the problems in the prior art such as the need to test the gas content data of samples using the on-site desorption method, the experiment must be carried out when the samples are just taken out of the well, and the high cost of drilling and limited samples;

[0096] 2. Considering the strong heterogeneity of marine - continental transitional shale, in the embodiments of the present invention, by dividing the work area into small units (i.e., single wells) according to well positions when calculating the marine - continental transitional shale gas resources, then calculating the shale gas resources of the small units controlled by each single well, and finally calculating the shale gas resources of the work area by superposition, the error caused by shale heterogeneity can be better reduced, the accuracy of the calculation result is improved, and it has good applicability at the same time.

[0097] Based on the above - mentioned embodiments, the present invention provides a calculation system for marine - continental transitional shale gas resources. Refer to Figure 6 as shown in Figure 6 which is the schematic diagram of the principle structure of the calculation system for marine - continental transitional shale gas resources according to the embodiments of the present invention. The calculation system for marine - continental transitional shale gas resources includes:

[0098] A data acquisition module 100, which is used to select a target work area and collect well - logging data in the target work area and formation basic characteristic data of the target horizon. The formation basic characteristic data includes the shale thickness of a single well and the shale density of a single well.

[0099] A sample collection module 200, which is used to collect shale samples, collect their basic data, and calculate the gas content of the collected downhole shale samples by using the desorption method.

[0100] A well - logging curve extraction module 300, which is used to extract well - logging curves sensitive to gas content respectively. The well - logging curves include acoustic transit time curve, natural gamma curve, compensated neutron curve, and density curve.

[0101] A gas content calculation module 400, which is used to establish a calculation model between gas content and the extracted well - logging curves. The calculation model is a multiple regression equation based on well - logging curves.

[0102] A gas content average value calculation module 500, which is used to calculate the predicted gas content values corresponding to each well position in the work area through the calculation model and take the average value of the single - well gas content in the work area. The average value of the single - well gas content is the average of the predicted gas content values calculated for each well position in the work area.

[0103] A verification module 600, which is used to select a new well position and obtain the measured gas content value corresponding to it, and calculate the predicted gas content value of the new well position through the calculation model, and fit the obtained measured gas content value with the predicted gas content value calculated by the calculation model to verify the applicability of the calculation model to the new well position.

[0104] A drawing module 700, which is used to draw a gas content isogram of the work area according to the predicted gas content values calculated for each well position after the applicability of the calculation model is verified, and divide the single - well controlled area through the gas content isogram.

[0105] The shale gas resource calculation module 800 is used to calculate the shale gas resource of each well position through the average gas content per well, the controlled area per well, the shale thickness per well, and the shale density per well, and finally obtain the shale gas resource of the work area by superposition.

[0106] Optionally, the specific multiple regression equation included in the calculation model established by the gas content calculation module 400 is as follows:

[0107] V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253

[0108] In the formula, V is the predicted gas content value, with the unit of m 3 / t; AC is the acoustic travel time, with the unit of μs / m; GR is the natural gamma ray, with the unit of API; CNL is the compensated neutron, with the unit of %; DEN is the density, with the unit of g / cm 3 .

[0109] Optionally, the average gas content calculation module 500 calculates the average gas content per well through the following formula:

[0110]

[0111] In the formula, V m is the average gas content per well, n is the number of well positions in the work area, and n is a positive integer.

[0112] Optionally, the shale gas resource calculation module 800 calculates the shale gas resource of each well position through the average gas content per well, the controlled area per well, the shale thickness per well, and the shale density per well, and specifically obtains it through the following formula:

[0113] Q m = 0.01×S×H×ρ×V m

[0114] In the formula, V m is the average gas content per well, S is the controlled area per well, H is the shale thickness per well, ρ is the shale density per well, and Q m is the shale gas resource of the m-th well position, m is a positive integer and m ≤ n.

[0115] Optionally, the shale gas resource calculation module 800 obtains the shale gas resource of the work area by superposition, and obtains it through the following formula:

[0116]

[0117] Wherein, Q is the shale gas resource volume of the work area obtained by superimposing the m well positions.

[0118] The calculation system for shale gas resource volume in the marine - continental transitional facies according to the embodiments of the present invention can execute the calculation method for shale gas resource volume in the marine - continental transitional facies provided in the above - mentioned embodiments. The calculation system for shale gas resource volume in the marine - continental transitional facies has the corresponding functional steps and beneficial effects of the method with the name described in the above - mentioned embodiments. For details, please refer to the embodiments of the calculation method for shale gas resource volume in the marine - continental transitional facies. The embodiments of the present invention will not be elaborated herein.

[0119] The embodiments of the present invention further provide an electronic device. The electronic device may include a processor and a memory, and the processor and the memory may be connected through a bus or other means. The processor may be a central processing unit (CPU). The processor may also be other general - purpose processors, digital signal processors (DSPs), application - specific integrated circuits (ASICs), field - programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., or a combination of the above - mentioned various chips. The memory, as a non - transient computer - readable storage medium, can be used to store non - transient software programs, non - transient computer - executable programs, and modules, such as the program instructions / modules corresponding to the calculation method for shale gas resource volume in the marine - continental transitional facies in the embodiments of the present invention. The processor runs the non - transient software programs, instructions, and modules stored in the memory, thereby performing various functional applications and data processing of the processor, that is, implementing the calculation method for shale gas resource volume in the marine - continental transitional facies in the above - mentioned method embodiments.

[0120] The memory may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created by the processor, etc. In addition, the memory may include high - speed random - access memory, and may also include non - transient memory, such as at least one magnetic disk storage device, flash memory device, or other non - transient solid - state storage devices. The one or more modules are stored in the memory and, when executed by the processor, execute the calculation method for shale gas resource volume in the marine - continental transitional facies in the Figure 1 embodiments shown. The specific details of the above - mentioned electronic device can be correspondingly referred to Figure 1For an understanding of the corresponding relevant descriptions and effects in the illustrated embodiments, details are not elaborated herein. Those skilled in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above methods. Among them, the storage medium can be a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory, a Hard Disk Drive (abbreviation: HDD), or a Solid-State Drive (SSD), etc.; the storage medium can also include a combination of the above types of memories.

[0121] In the specification provided herein, a large number of specific details are set forth. However, it is understood that the embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0122] Similarly, it should be understood that, in order to streamline the present disclosure and assist in understanding one or more of the various inventive aspects, in the foregoing description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the disclosed method should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the inventive aspects lie in less than all the features of the single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate embodiment of the present invention.

[0123] It should be noted that the above embodiments illustrate rather than limit the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A calculation method for shale gas resources in the transitional marine - continental facies, characterized in that, The calculation method applied to the shale gas resource volume in the marine - continental transitional facies includes: S1. Select a target work area, collect well - logging data in the target work area and formation basic characteristic data of the target horizon, where the formation basic characteristic data includes the single - well shale thickness and the single - well shale density; S2. Collect shale samples, gather their basic data, and use the desorption method for the downhole shale samples collected to calculate their gas content; S3. Extract well - logging curves sensitive to gas content respectively. The well - logging curves include the acoustic transit - time curve, the natural gamma curve, the compensated neutron curve, and the density curve; S4. Establish a calculation model between the gas content and the extracted well - logging curves. The calculation model is a multiple regression equation based on the well - logging curves; S5. Calculate the predicted gas - content values corresponding to each well position in the work area through the calculation model, and take the average single - well gas content in the work area. The average single - well gas content is the average value of the predicted gas - content values calculated for each well position in the work area; S6. Select a new well position and obtain the measured gas - content value, as well as calculate the predicted gas - content value of the new well position through the calculation model. Fit the obtained measured gas - content value with the predicted gas - content value calculated by the calculation model to verify the applicability of the calculation model to the new well position; S7. After the applicability of the calculation model is verified, draw a gas - content isogram map of the work area based on the predicted gas - content values calculated for each well position, and divide the single - well controlled area through the gas - content isogram; S8. Calculate the single - well shale gas resource volume corresponding to each well position through the average single - well gas content, the single - well controlled area, the single - well shale thickness, and the single - well shale density, and finally obtain the shale gas resource volume of the work area through superposition.

2. The calculation method for shale gas resources in the transitional marine - continental facies according to claim 1, characterized in that, In step S4, the specific multiple regression equation included in the calculation model is: V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253 Wherein, V is the predicted gas content value, with the unit of m 3 / t; AC is the acoustic time difference, with the unit of μs / m; GR is the natural gamma ray, with the unit of API; CNL is the compensated neutron, with the unit of %; DEN is the density, with the unit of g / cm 3 .

3. The calculation method for shale gas resources in the transitional marine - continental facies according to claim 2, characterized in that, In step S5, the average single - well gas content is calculated through the following formula: Where, V m is the average gas content of a single well, n is the number of well positions in the work area, and n is a positive integer.

4. The calculation method for shale gas resources in the transitional marine - continental facies according to claim 3, characterized in that, In step S8, the calculation of the single - well shale gas resource volume corresponding to each well position through the average single - well gas content, the single - well controlled area, the single - well shale thickness, and the single - well shale density is specifically calculated through the following formula: Q m = 0.01 × S × H × ρ × V m Wherein, V m is the average gas content per well, S is the controlled area per well, H is the shale thickness per well, ρ is the shale density per well, and Q m is the shale gas resource amount per well corresponding to the m-th well position, where m is a positive integer and m ≤ n.

5. The calculation method for shale gas resources in the transitional marine - continental facies according to claim 4, characterized in that, In step S8, the calculation of obtaining the shale gas resource volume of the work area through superposition is calculated through the following formula: In the formula, Q is the shale gas resource volume of the work area obtained by superposition corresponding to m well positions.

6. A calculation system for shale gas resources in the transitional marine - continental facies, characterized in that, The calculation system applied to the shale gas resource volume in the marine - continental transitional facies includes: A data acquisition module, which is used to select a target work area, collect well - logging data in the target work area and formation basic characteristic data of the target horizon, where the formation basic characteristic data includes the single - well shale thickness and the single - well shale density; A sample collection module, which is used to collect shale samples, gather their basic data, and use the desorption method for the downhole shale samples collected to calculate their gas content; A well - logging curve extraction module, which is used to extract well - logging curves sensitive to gas content respectively. The well - logging curves include the acoustic transit - time curve, the natural gamma curve, the compensated neutron curve, and the density curve; The gas content calculation module is used to establish a calculation model for the gas content and the extracted logging curves, and the calculation model is a multiple regression equation based on the logging curves; The average gas content calculation module is used to calculate the predicted gas content values corresponding to each well position in the work area through the calculation model, and take the average single-well gas content in the work area. The average single-well gas content is the average value of the predicted gas content values calculated for each well position in the work area; The verification module is used to select a new well position and obtain the measured gas content value corresponding thereto, and calculate the predicted gas content value of the new well position through the calculation model, and fit the obtained measured gas content value with the predicted gas content value calculated by the calculation model to verify the applicability of the calculation model to the new well position; The drawing module is used to draw a gas content isogram of the work area according to the predicted gas content values calculated for each well position after the applicability of the calculation model is verified, and divide the single-well control area through the gas content isogram; The shale gas resource amount calculation module is used to calculate the single-well shale gas resource amount corresponding to each well position through the average single-well gas content, the single-well control area, the single-well shale thickness, and the single-well shale density, and finally obtain the shale gas resource amount of the work area by superposition.

7. The calculation system for the shale gas resource volume applied to the marine-terrestrial transitional facies, as claimed in claim 6, is characterized in that The multiple regression equation included in the calculation model established by the gas content calculation module is specifically: V = 0.027026×AC + 0.000418×GR + 0.009108×CNL - 0.15319×DEN - 4.66253 Wherein, V is the predicted gas content value, with the unit of m 3 / t; AC is the acoustic time difference, with the unit of μs / m; GR is the natural gamma ray, with the unit of API; CNL is the compensated neutron, with the unit of %; DEN is the density, with the unit of g / cm 3 .

8. The calculation system for the shale gas resource volume applied to the marine-terrestrial transitional facies, as claimed in claim 7, is characterized in that The average gas content calculation module calculates and obtains the average single-well gas content through the following formula: Where V m is the average gas content per single well, n is the number of well positions in the work area, and n is a positive integer.

9. The calculation method for the shale gas resource volume applied to the marine-terrestrial transitional facies, as claimed in claim 8, is characterized in that The shale gas resource amount calculation module calculates the single-well shale gas resource amount corresponding to each well position through the average single-well gas content, the single-well control area, the single-well shale thickness, and the single-well shale density, and specifically calculates and obtains it through the following formula: Q m = 0.01 × S × H × ρ × V m Wherein, V m is the average gas content per well, S is the controlled area per well, H is the shale thickness per well, ρ is the shale density per well, and Q m is the shale gas resource volume per well corresponding to the m-th well position, where m is a positive integer and m ≤ n.

10. The calculation system for the shale gas resource volume applied to the marine-terrestrial transitional facies, as claimed in claim 9, is characterized in that The shale gas resource amount calculation module obtains the shale gas resource amount of the work area by superposition, and calculates and obtains it through the following formula: In the formula, Q is the shale gas resource amount of the work area obtained by superposition corresponding to m well positions.

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