A method and device for calculating paleo-pressure of a clastic rock gas reservoir, an electronic device and a storage medium

Abstract

The application provides a method and device for calculating paleo-pressure of a clastic rock gas reservoir, an electronic device and a storage medium, wherein the method comprises the following steps: obtaining a fitting relationship between a rock formation compaction coefficient and porosity by using a data fitting method based on discrete values of the rock formation compaction coefficient and porosity of a clastic rock sample under different effective stresses; obtaining the rock formation compaction coefficient at any geologic history time by using the fitting relationship between the rock formation compaction coefficient and porosity based on the porosity at the geologic history time; determining a paleo-pore volume at the geologic history time according to the rock formation compaction coefficient at the geologic history time and confining pressure; and determining a formation paleo-pressure at the geologic history time according to a measured formation pressure, temperature and pore volume of a present clastic rock gas reservoir, and a paleo-geotemperature and paleo-pore volume at the geologic history time.

Description

Technical Field

[0001] This invention belongs to the technical field of geological exploration, specifically relating to a method, apparatus, electronic equipment, and storage medium for calculating paleopressure in clastic gas reservoirs. Background Technology

[0002] Paleopressure reconstruction in sedimentary basins is a crucial aspect of basin analysis and hydrocarbon accumulation dynamics research, playing a vital role in oil and gas geological research and exploration. Paleopressure reconstruction studies utilize existing geological data, analytical and laboratory data, and the stratigraphic sedimentary and burial history to ultimately calculate the pore pressure or pore pressure coefficient of the reservoir at various geological periods during the uplift process.

[0003] There are now several methods for restoring paleopressure, which can be roughly divided into the following categories: (1) Restoring formation paleopressure using fluid inclusions. The paleopressure at the time of fluid capture is obtained by using the equilibrium relationship between the homogenization temperature and fluid composition of the same-phase hydrocarbon inclusions and brine inclusions. Common methods include: calculating the paleopressure of oil inclusions using PVT-sim software and calculating the paleopressure using laser Raman displacement of methane inclusions. These methods require a large number of downhole observable and measurable hydrocarbon inclusions, which are not applicable to reservoirs with few or small inclusions; (2) Using mudstone sonic transit time data. Based on the principle of irreversible mudstone compaction, the paleopressure at the maximum burial depth of the formation can be derived. Common methods include the equivalent depth method and the Fillippone formula method. These methods can only estimate the formation pore pressure at the maximum burial depth of the formation; (3) Using basin simulation soft water such as PetroMod and BasinMod. The method of restoring the paleopressure characteristics of single wells, profiles and planes is based on the stripping model. In order to obtain reasonable calculation results, a large amount of geological history evolution data is often required. However, these data are difficult to obtain and require a lot of debugging and testing. (4) For carbonate rock formations that lack oil inclusions and gaseous hydrocarbon brine inclusions, calcite twins can be used as paleopressure gauges. Combined with fracture analysis, suture roughness and rock mechanical parameters, the evolution of paleofluid pressure can be restored by differential paleostress method. This method can only qualitatively analyze whether there is paleooverpressure and cannot quantitatively calculate the paleopressure value of the formation in each historical period. (5) Other methods include using mineral veins to estimate paleopressure, estimating the formation pressure of clay minerals based on the formation temperature and actual curves of clay minerals, and tectonic stress method for studying the paleopressure of formations under tectonic compression. These methods are all under certain assumptions and can only qualitatively estimate the size of paleopressure.

[0004] In summary, most existing methods for calculating reservoir paleopressure have limitations, being only applicable to qualitative estimations or specific regions. While more reliable quantitative methods, such as laser Raman displacement of methane inclusions for paleopressure calculation, require extensive observation and testing of microscopic fluid inclusions, they can only calculate the paleopressure value at the specific historical moment of inclusion filling. Paleopressure values ​​for other historical periods are based on fitting and extrapolation from test points. Currently, there is a lack of a quantitative paleopressure calculation method that is highly applicable to clastic gas reservoirs and considers the continuous evolution over historical time. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a method, apparatus, electronic device, and storage medium for calculating paleopressure in clastic gas reservoirs.

[0006] This application provides a method for calculating reservoir pressure in clastic gas reservoirs, including:

[0007] Based on the discrete values ​​of rock compaction coefficient and porosity of clastic rock samples under different effective stresses, a data fitting method was used to obtain the fitting relationship between rock compaction coefficient and porosity.

[0008] Based on the porosity at any geological time, the compaction coefficient of the rock formation at any geological time is obtained by fitting the relationship between the compaction coefficient and porosity.

[0009] The paleopore volume for any given geological history time is determined based on the rock strata compaction coefficient and confining pressure at that time.

[0010] The paleopressure of the formation at any given geological time is determined based on the measured formation pressure, temperature, and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any given geological time.

[0011] In some embodiments, the discrete values ​​of rock formation compaction coefficient and porosity of clastic rock samples under different effective stresses are used to obtain a fitting relationship between the rock formation compaction coefficient and porosity using a data fitting method, specifically including the following steps:

[0012] Based on the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses, a data fitting method was used to fit the data and obtain the fitting relationship between the rock formation compaction coefficient and the effective stress.

[0013] Based on the discrete values ​​of porosity of the clastic rock samples under different effective stresses, a data fitting method was used to fit the data and obtain the fitting relationship between effective stress and porosity.

[0014] The fitting formulas for the compaction coefficient and effective stress of the rock formation and the fitting formulas for the effective stress and porosity are combined and transformed to obtain the fitting formula for the compaction coefficient and porosity of the rock formation.

[0015] In some embodiments, the porosity at any geological historical time is calculated as follows: based on the measured formation depth of the clastic gas reservoir at present and the formation depth at any geological historical time, the porosity at any geological historical time is calculated using a depth-porosity relationship index model.

[0016] In some embodiments, determining the paleopore volume for any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time specifically includes the following steps:

[0017] Integral transformation is performed on the function of compaction coefficient of rock formation with changes in pore volume and confining pressure;

[0018] Based on the rock strata compaction coefficient and confining pressure at any given geological time, the paleopore volume at any given geological time is calculated using the rock strata compaction coefficient after integral transformation as a function of the changes in pore volume and confining pressure.

[0019] In some embodiments, the confining pressure at any geological historical time is obtained by obtaining the confining pressure at any geological historical time according to a preset basin simulation burial depth-geological time evolution diagram.

[0020] In some embodiments, the specific formula for calculating the paleopore volume at any given geological time is as follows:

[0021]

[0022] In the formula, e is the base of the natural logarithm; d is the integration constant; V pt C represents the pore volume at any given geological time t; pct P is the rock compaction coefficient at any given geological time t; ct Let be the confining pressure at any given geological time t.

[0023] In some embodiments, the integral constant d is obtained by: calculating the integral constant d based on the discrete values ​​of the rock formation compaction coefficient and pore volume under any test confining pressure conditions, using the integral transformation of the rock formation compaction coefficient as a function of the pore volume and the change in confining pressure.

[0024] Embodiments of this application also provide a paleopressure calculation device for clastic gas reservoirs, comprising:

[0025] The fitting module is used to obtain discrete values ​​of rock formation compaction coefficient and porosity of rock samples from clastic rock formations under different effective stresses. The data fitting method is used to obtain the fitting relationship between the rock formation compaction coefficient and porosity.

[0026] The first calculation module is used to obtain the compaction coefficient of the rock strata at any geological history time based on the porosity at any geological history time, through the fitting relationship between the compaction coefficient of the rock strata and the porosity.

[0027] The second calculation module is used to determine the paleopore volume of any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time.

[0028] The third calculation module is used to determine the paleopressure of the formation at any given geological time based on the measured formation pressure, temperature, and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any given geological time.

[0029] Embodiments of this application also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, which, when executed by the processor, performs the paleopressure calculation method for clastic gas reservoirs described in any one of the claims.

[0030] Embodiments of this application also provide a storage medium storing a computer program that can be executed by one or more processors and can be used to implement the paleopressure calculation method for clastic gas reservoirs described in any of the preceding claims.

[0031] This application provides a method, apparatus, electronic device, and storage medium for calculating paleopressure in clastic gas reservoirs. Using the rock formation compaction coefficient, a rock elastic parameter, as a key model parameter, it theoretically establishes the pore volume V of the rock at any given geological time. pt Compaction coefficient C of rock formation pct Confining pressure P ct The quantitative relationship is then used to calculate the paleopressure P of the stratigraphy at any given geological time using the ideal gas law. pt The parameters required for the calculation process are easy to obtain, and the cost of testing porosity and rock formation compaction coefficients under different effective stresses is low. Furthermore, it can continuously calculate the paleopressure values ​​of formations at any geological time. To a certain extent, it solves the problem that previous quantitative calculation methods for low-level paleopressure relied on the observation and testing of microscopic fluid inclusions and were difficult to continuously calculate the paleopressure of formations in various geological periods. It plays an important role in basin analysis and hydrocarbon accumulation dynamics research, and has significant industrial application value in oil and gas exploration and evaluation. Attached Figure Description

[0032] The scope of this disclosure can be better understood by reading the following detailed description of exemplary embodiments in conjunction with the accompanying drawings. The accompanying drawings are:

[0033] Figure 1 A flowchart provided for Embodiment 1 of this application;

[0034] Figure 2 This is a graph showing the change of the rock formation compaction coefficient of the clastic rock sample provided in Example 2 of this application as the effective stress increases.

[0035] Figure 3 A graph showing the correlation between effective stress and porosity for the clastic rock sample with well number-sample number J30-18-04 provided in Example 2 of this application;

[0036] Figure 4 Example 2 of this application shows the simulated burial depth-geological time evolution diagram of the section 3553.79M of the J30-18 well in the Hangjin Banner area of ​​the Ordos Basin.

[0037] Figure 5 This is a temperature-geological time evolution diagram of the simulated thermal history of the Ordos Basin at 3553.79M from well J30-18 in the Hangjin Banner area of ​​the Ordos Basin, provided in Example 2 of this application.

[0038] Figure 6 This is a simulated stratigraphic paleopressure-geological age relationship diagram provided in Example 2 of this application;

[0039] Figure 7 This is a structural block diagram of the paleopressure calculation device for clastic gas reservoirs provided in Embodiment 3 of this application. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0042] If the application documents contain similar descriptions such as "first, second, third", the following explanation shall be added: In the following description, the terms "first, second, third" are used only to distinguish similar objects and do not represent a specific order of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0044] Example 1:

[0045] In view of the problems existing in the background technology, such as Figure 1 As shown, this application provides a method for calculating paleopressure in clastic gas reservoirs. The method is applied to an electronic device, which may be a server, mobile terminal, computer, cloud platform, etc. The functions implemented by the device data processing provided in this application embodiment can be achieved by the processor of the electronic device calling program code, wherein the program code can be stored in a computer storage medium. The method for calculating paleopressure in clastic gas reservoirs includes:

[0046] Step S100: Based on the discrete values ​​of rock compaction coefficient and porosity of clastic rock samples under different effective stresses, a data fitting method is used to obtain the fitting relationship between rock compaction coefficient and porosity.

[0047] In this embodiment, the discrete values ​​of the rock formation compaction coefficient and porosity of clastic rock samples from clastic rock formations under different effective stresses are obtained by testing the rock formation compaction coefficient and porosity of clastic rock samples from clastic rock formations under normal pressure and different confining pressures. Preferably, the method for obtaining the rock formation compaction coefficient and porosity is: using a PoroPDP-200 overburden porosity meter to test the rock formation compaction coefficient and porosity using the helium method.

[0048] In this embodiment, the discrete values ​​of the compaction coefficient and porosity of clastic rock samples from clastic rock formations under different effective stresses are obtained by data fitting methods to obtain a fitting relationship between the compaction coefficient and porosity of the rock formations. The data fitting methods include exponential fitting methods, logarithmic fitting methods, and power-law fitting methods, with power-law fitting methods being preferred. In this embodiment, the data fitting method is exemplified by the power-law fitting method, specifically including the following steps:

[0049] Step S101: Based on the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses, a power-law fitting method is used to fit the values, obtaining a fitting relationship between the rock formation compaction coefficient and the effective stress. The fitting relationship between the rock formation compaction coefficient and the effective stress is as follows:

[0050]

[0051] In the formula, C pc σ is the compaction coefficient of the rock formation; eff Let be the effective stress, and 'a' be the discrete value fitting coefficient. The discrete value fitting coefficient 'a' can be obtained from the graph showing the change in the rock formation compaction coefficient of the clastic rock sample as the effective stress increases.

[0052] Step S102: Based on the discrete values ​​of porosity of the clastic rock sample under different effective stresses, a power-law fitting method is used to fit the data to obtain a fitting relationship between effective stress and porosity. The fitting relationship between effective stress and porosity is as follows:

[0053] σ eff =bφ c (2)

[0054] In the formula, σ eff φ represents the effective stress; φ represents the porosity; b and c are discrete value fitting coefficients. The discrete value fitting coefficients b and c can be obtained from the correlation graph of effective stress and porosity of the clastic rock sample obtained from the test.

[0055] Step S103: The fitting formulas for the compaction coefficient and effective stress of the rock formation and the fitting formulas for the effective stress and porosity are combined and transformed to obtain the fitting formula for the compaction coefficient and porosity of the rock formation. The fitting formula for the compaction coefficient and porosity of the rock formation is as follows:

[0056]

[0057] In the formula, C pc φ is the rock formation compaction coefficient; φ is the porosity; a, b, and c are all discrete fitting coefficients.

[0058] Step S200: Based on the porosity at any geological historical time, the compaction coefficient of the rock strata at any geological historical time is obtained through the fitting relationship between the compaction coefficient of the rock strata and the porosity.

[0059] In the embodiments of this application, the rock strata compaction coefficient C at any geological history time is described. pct The specific calculation formula is as follows:

[0060]

[0061] In the formula, φ t denoted as porosity at any given geological time t; a, b, and c are all discrete fitting coefficients.

[0062] In this embodiment of the application, the porosity φ at any geological historical time t The depth-porosity index can be calculated using a depth-porosity relationship index model, based on the measured formation depth and porosity of current clastic gas reservoirs and the formation depth at any given geological time. The specific calculation formula for the depth-porosity relationship index model is as follows:

[0063]

[0064] In the formula, φ0 is the measured porosity of the current clastic gas reservoir, which is an a priori value; e is the base of the natural logarithm, which is an a priori value; k is the compaction factor, which is an a priori value; H0 is the measured formation depth of the current clastic gas reservoir, which is an a priori value; H t H represents the stratigraphic depth at any given geological time t, wherein the functional relationship between any given geological time t and stratigraphic depth H can be obtained from the basin simulation burial depth-geological time evolution diagram.

[0065] Step S300: Determine the paleopore volume for any geological historical time based on the rock strata compaction coefficient and confining pressure for any geological historical time.

[0066] In this embodiment of the application, determining the paleopore volume for any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time specifically includes the following steps:

[0067] Step S301: Perform an integral transformation on the function of the compaction coefficient of the rock formation with respect to the changes in pore volume and confining pressure.

[0068] In this embodiment of the application, the function of the rock formation compaction coefficient with respect to pore volume and confining pressure variation is as follows:

[0069]

[0070] In the formula, C pc ΔP is the compaction coefficient of the rock formation. c V is the change in confining pressure. p ΔV represents the pore volume. p This represents the change in pore volume.

[0071] The integral transformation of both sides of the equation relating the compaction coefficient of the rock formation to the changes in pore volume and confining pressure yields the following function:

[0072]

[0073] In the formula, V p ρ is the pore volume; e is the base of the natural logarithm, a priori value; C pc P is the compaction coefficient of the rock formation. c d is the confining pressure; d is the integration constant.

[0074] In this embodiment, the integral constant d is obtained as follows: based on the discrete values ​​of the rock formation compaction coefficient and pore volume under arbitrary test confining pressure conditions, the integral constant d is calculated as a function of the rock formation compaction coefficient after integral transformation and the changes in pore volume and confining pressure. The specific calculation formula is as follows:

[0075] d=C pc1 ·P c1 -ln V p1 (8)

[0076] In the formula, C pc1 To test the confining pressure P c1 Discrete values ​​of the formation compaction coefficient under the given conditions, V p1 To test the confining pressure P c1 Discrete values ​​of pore volume under certain conditions.

[0077] Step S302: Based on the rock strata compaction coefficient and confining pressure at any geological historical time, the paleopore volume at any geological historical time is calculated using the rock strata compaction coefficient after integral transformation as a function of pore volume and confining pressure change.

[0078] In this embodiment of the application, the paleopore volume V at any geological historical time is... pt for:

[0079]

[0080] In the formula, e is the base of the natural logarithm, an a priori value; d is the integration constant; V pt C represents the pore volume at any geological time t. pct P is the formation compaction coefficient at any geological time t; ct Let t be the confining pressure at any given geological time t.

[0081] In this embodiment of the application, the confining pressure P at any geological history time t is... ct The method of obtaining the data is as follows: the confining pressure at any geological historical time is obtained according to the preset basin simulation burial depth-geological time evolution map.

[0082] Specifically:

[0083] P ct =Pc0 +ρ s (H t -H0), (10)

[0084] In the formula, P c0 The confining pressure of the current clastic gas reservoir; ρ s H represents the empirical value of shallow formation density; H0 represents the current formation depth of the clastic gas reservoir; H t H represents the stratigraphic depth at any given geological time t, wherein the functional relationship between any given geological time t and stratigraphic depth H can be obtained from the basin simulation burial depth-geological time evolution diagram.

[0085] Step S400: Determine the paleopressure of the formation at any geological time based on the measured formation pressure, temperature, and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any geological time.

[0086] In this embodiment of the application, the step of obtaining the paleopressure of the formation at any geological history time based on the measured formation pressure, temperature, and pore volume of the current clastic gas reservoir, as well as the paleotemperature and paleopore volume at any geological history time, specifically involves obtaining the paleopressure of the formation at any geological history time based on the ideal gas equation of state, using the measured formation pressure, temperature, and pore volume of the current clastic gas reservoir as a starting point, and the paleotemperature and paleopore volume at any geological history time.

[0087] In the embodiments of this application, the paleopressure P of the stratigraphy at any geological time t is... pt for:

[0088]

[0089] In the formula, P p0 T0 and V p0 V represents the measured formation pressure, geothermal temperature, and pore volume of the current clastic gas reservoir, which are a priori values; pt T represents the pore volume at any given geological time t; t Let T be the geothermal temperature at any given geological time t. Wherein, the formation temperature T at any given geological time t is... t It can be obtained from the temperature-geological time evolution diagram of the basin thermal history simulation.

[0090] This application provides a method, apparatus, electronic device, and storage medium for calculating paleopressure in clastic gas reservoirs. Using the rock formation compaction coefficient, a rock elastic parameter, as a key model parameter, it theoretically establishes the pore volume V of the rock at any given geological time. pt Compaction coefficient C of rock formation pct Confining pressure Pct The quantitative relationship is then used to calculate the paleopressure P of the stratigraphy at any given geological time using the ideal gas law. pt The parameters required for the calculation process are easy to obtain, and the cost of testing porosity and rock formation compaction coefficient under different effective stresses is low. Furthermore, it can continuously calculate the paleopressure value of the formation at any geological history time. To a certain extent, it solves the problem that previous quantitative calculation methods for formation paleopressure relied on the observation and testing of microscopic fluid inclusions and were difficult to continuously calculate the formation paleopressure of various geological periods. It plays an important role in basin analysis and hydrocarbon accumulation dynamics research, and has significant industrial application value in oil and gas exploration and evaluation.

[0091] Example 2

[0092] Based on the above embodiments, Embodiment 2 of the present invention can also provide a method for calculating the paleopressure of the clastic gas reservoir, specifically including the following steps:

[0093] Step S500: Based on the discrete values ​​of rock compaction coefficient and porosity of clastic rock samples under different effective stresses, a data fitting method is used to obtain the fitting relationship between rock compaction coefficient and porosity.

[0094] In this embodiment, the method for obtaining the discrete values ​​of the rock formation compaction coefficient and porosity of clastic rock samples from clastic rock strata under different effective stresses is as follows: Clastic rock samples from the clastic rock strata to be calculated are obtained, preferably a series of samples as shown in Table 1. The formation compaction coefficient and porosity of the clastic rock samples are tested under normal pressure and different confining pressures to obtain the discrete values ​​of the rock formation compaction coefficient and porosity of the clastic rock samples from clastic rock strata under different effective stresses. In this embodiment, the method for obtaining the rock formation compaction coefficient and porosity preferably uses a PoroPDP-200 overburden porosity meter to test the rock formation compaction coefficient and porosity of the clastic rock samples using the helium method.

[0095] Table 1 Information on core samples from 11 wells in Hangjinqi area of ​​Ordos Basin

[0096]

[0097] In this embodiment, the discrete values ​​of the compaction coefficient and porosity of clastic rock samples from clastic rock formations under different effective stresses are obtained by data fitting methods to obtain a fitting relationship between the compaction coefficient and porosity of the rock formations. The data fitting methods include exponential fitting methods, logarithmic fitting methods, and power-law fitting methods, with power-law fitting methods being preferred. In this embodiment, the power-law fitting method is used as an example, specifically including the following steps:

[0098] Step S501: Based on the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses, a power-law fitting method is used to fit the values, obtaining the fitting relationship between the rock formation compaction coefficient and the effective stress, as follows: Figure 2 As shown. The fitting formula for the compaction coefficient and effective stress of the rock formation is:

[0099]

[0100] In the formula, C pc σ is the compaction coefficient of the rock formation; eff Let be the effective stress, and 'a' be the discrete value fitting coefficient. The discrete value fitting coefficient 'a' can be obtained from the graph showing the change in the rock formation compaction coefficient of the clastic rock sample as the effective stress increases.

[0101] In this application embodiment, samples with methane inclusions and laser Raman displacement reconstruction of formation paleopressure values ​​are preferred, as shown in Table 1, such as the clastic rock sample numbered J30-18-04.

[0102] Here, as Figure 2 As shown, from the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses, it can be seen that the rock formation compaction coefficient is highly correlated with the effective stress of the rock. The properties of the rock skeleton under effective stress are the same as the properties of the rock as a whole under the combined action of confining pressure and pore pressure. Therefore, the correlation between effective stress and rock formation compaction coefficient fitted by test data can be used to predict the rock formation compaction coefficient in various historical periods.

[0103] Step S502: Based on the discrete values ​​of porosity of the clastic rock sample under different effective stresses, a power-law fitting method is used to fit the data to obtain a fitting relationship between effective stress and porosity. The fitting relationship between effective stress and porosity is as follows:

[0104] σ eff =bφ c (13)

[0105] In the formula, σ eff φ represents the effective stress; φ represents the porosity; b and c are discrete value fitting coefficients. The discrete value fitting coefficients b and c can be obtained from the correlation graph of effective stress and porosity of the clastic rock sample obtained from the test.

[0106] Step S503: The fitting formulas for the compaction coefficient and effective stress of the rock formation and the fitting formulas for the effective stress and porosity are merged and transformed to obtain the fitting formula for the compaction coefficient and porosity of the rock formation. The fitting formula for the compaction coefficient and porosity of the rock formation is as follows:

[0107]

[0108] In the formula, C pc denoted as φ, representing the compaction coefficient of the rock formation; φ as the porosity; and a, b, and c as coefficients for fitting discrete values. Taking the clastic rock sample with well number-sample number J30-28-04 as an example, the coefficient for fitting discrete values ​​a ranges from... Figure 2 The graph showing the variation of the rock formation compaction coefficient of the clastic rock sample with increasing effective stress yields a discrete value fitting coefficient a of 0.0000007; the discrete value fitting coefficients b and c are as follows: Figure 3 The correlation graph of effective stress and porosity of the clastic rock sample shows that the discrete value fitting coefficient b is 171.51 and the discrete value fitting coefficient c is -2.249.

[0109] Step S600: Based on the porosity at any geological historical time, the compaction coefficient of the rock strata at any geological historical time is obtained through the fitting relationship between the compaction coefficient of the rock strata and the porosity.

[0110] In the embodiments of this application, the rock strata compaction coefficient C at any geological history time is described. pct The specific calculation formula is as follows:

[0111]

[0112] In the formula, φ t Let be the porosity at any given geological time t; a, b, and c are all discrete fitting coefficients. The discrete fitting coefficient 'a' can be obtained from the graph showing the change in the rock formation compaction coefficient of the clastic rock sample with increasing effective stress. The discrete fitting coefficients 'b' and 'c' can be obtained from the correlation graph between the effective stress and porosity of the clastic rock sample.

[0113] In this embodiment of the application, the porosity φ at any geological historical time t The depth-porosity index model can be used for calculation. The specific calculation formula for the depth-porosity index model is as follows:

[0114]

[0115] In the formula, φ0 is the measured porosity of the current clastic gas reservoir, which is an a priori value; e is the base of the natural logarithm, which is an a priori value; k is the compaction factor, which is an a priori value; H0 is the measured formation depth of the current clastic gas reservoir, which is an a priori value; H t H represents the stratigraphic depth at any given geological time t. The functional relationship between the given geological time t and the stratigraphic depth H can be obtained from a basin simulation burial depth-geological time evolution diagram. Taking the clastic rock sample with well number-sample number J30-18-04 as an example, ... Figure 4The diagram shown is a simulated basin burial depth-geological time evolution diagram, with stratigraphic depth H. t for Figure 4 The burial depth and geological history time t are as follows: Figure 4 The geological age is given, and the measured stratigraphic depth H0 of the clastic gas reservoir is 3553.79 m. The stratigraphic depth H at any geological time t = 100 Ma is given. t It is 4200m.

[0116] Step S700: Determine the paleopore volume for any geological historical time based on the rock strata compaction coefficient and confining pressure for any geological historical time.

[0117] In this embodiment of the application, determining the paleopore volume for any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time specifically includes the following steps:

[0118] Step S701: Perform an integral transformation on the function of the compaction coefficient of the rock formation with respect to the changes in pore volume and confining pressure.

[0119] In this embodiment of the application, the function of the rock formation compaction coefficient with respect to pore volume and confining pressure variation is as follows:

[0120]

[0121] In the formula, C pc ΔP is the compaction coefficient of the rock formation. c V is the change in confining pressure. p ΔV represents the pore volume. p This represents the change in pore volume.

[0122] The integral transformation of both sides of the equation relating the compaction coefficient of the rock formation to the changes in pore volume and confining pressure yields the following function:

[0123]

[0124] In the formula, V p ρ is the pore volume; e is the base of the natural logarithm, a priori value; C pc P is the compaction coefficient of the rock formation. c d is the confining pressure; d is the integration constant.

[0125] In this embodiment, the integral constant d is obtained as follows: based on the discrete values ​​of the rock formation compaction coefficient and pore volume under arbitrary test confining pressure conditions, the integral constant d is calculated as a function of the rock formation compaction coefficient after integral transformation and the changes in pore volume and confining pressure. The specific calculation formula is as follows:

[0126] d=C pc1 ·P c1 -ln V p1 (19)

[0127] In the formula, C pc1 To test the confining pressure P c1 Discrete values ​​of the formation compaction coefficient under the given conditions, V p1 To test the confining pressure P c1 Discrete values ​​of pore volume under certain conditions.

[0128] Step S702: Based on the rock strata compaction coefficient and confining pressure at any geological historical time, the paleopore volume at any geological historical time is calculated using the rock strata compaction coefficient after integral transformation as a function of pore volume and confining pressure change.

[0129] In this embodiment of the application, the paleopore volume V at any geological historical time is... pt for:

[0130]

[0131] In the formula, e is the base of the natural logarithm, an a priori value; d is the integration constant; V pt C represents the pore volume at any geological time t. pct P is the rock strata compaction coefficient at any given geological time t; ct Let t be the confining pressure at any given geological time t.

[0132] In this embodiment of the application, the confining pressure P at any geological history time t is... ct The method of obtaining the data is as follows: the confining pressure at any geological historical time is obtained according to the preset basin simulation burial depth-geological time evolution map.

[0133] Specifically:

[0134] P ct =P c0 +ρ s (H t -H0), (21)

[0135] In the formula, P c0 The confining pressure of the current clastic gas reservoir; ρ s The density of shallow strata is taken as an empirical value of 2.65 g / cm³. 3 H0 represents the current stratigraphic depth of the clastic gas reservoir; H tH represents the stratigraphic depth at any given geological time t, where the functional relationship between the given geological time t and the stratigraphic depth H can be obtained from a basin simulation burial depth-geological time evolution diagram. Taking the clastic rock sample with well number-sample number J30-18-04 as an example, ... Figure 4 As shown, the formation depth H t for Figure 4 The burial depth and geological history time t are as follows: Figure 4 Based on the geological age, the measured stratigraphic depth H0 of the clastic gas reservoir is currently 3553.79 m. The stratigraphic depth H at any geological time t = 100 Ma is... t It is 4200m.

[0136] Step S800: Determine the paleopressure of the formation to the specified geological time based on the measured formation pressure, temperature, and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any given geological time.

[0137] In this embodiment of the application, the step of obtaining the paleopressure of the formation at any geological history time based on the measured formation pressure, temperature, and pore volume of the current clastic gas reservoir, as well as the paleotemperature and paleopore volume at any geological history time, specifically involves obtaining the paleopressure of the formation at any geological history time based on the ideal gas equation of state, using the measured formation pressure, temperature, and pore volume of the current clastic gas reservoir as a starting point, and the paleotemperature and paleopore volume at any geological history time.

[0138] In the embodiments of this application, the paleopressure P of the stratigraphy at any geological time t is... pt :

[0139]

[0140] In the formula, P p0 T0 and V p0 V represents the measured formation pressure, geothermal temperature, and pore volume of the current clastic gas reservoir, which are a priori values; pt T represents the pore volume at any given geological time t; t Let T be the geothermal temperature at any given geological time t. Wherein, the formation temperature T at any given geological time t is... t This can be obtained from the basin's thermal history simulation temperature-geological time evolution diagram. Taking the clastic rock sample with well number-sample number J30-18-04 as an example, such as... Figure 5 As shown, the geological history time t is Figure 5 The geological age in the text, and the formation temperature T at any geological history time t = 100 Ma. t The temperature is 160℃.

[0141] This application provides a method, apparatus, electronic device, and storage medium for calculating paleopressure in clastic gas reservoirs. Using the rock formation compaction coefficient, a rock elastic parameter, as a key model parameter, it theoretically establishes the pore volume V of the rock at any given geological time. pt Compaction coefficient C of rock formation pct Confining pressure P ct The quantitative relationship is then used to calculate the paleopressure P of the stratigraphy at any given geological time using the ideal gas law. pt The parameters required for the calculation process are easy to obtain, and the cost of testing porosity and rock formation compaction coefficient under different effective stresses is low. Furthermore, it can continuously calculate the paleopressure value of the formation at any geological history time. To a certain extent, it solves the problem that previous quantitative calculation methods for formation paleopressure relied on the observation and testing of microscopic fluid inclusions and were difficult to continuously calculate the formation paleopressure of various geological periods. It plays an important role in basin analysis and hydrocarbon accumulation dynamics research, and has significant industrial application value in oil and gas exploration and evaluation.

[0142] Using the method described in this application, the calculated paleopressure values ​​are as follows: Figure 6 The lines in the simulated paleopressure-geological age diagram, and the values ​​of paleopressure reconstructed from methane inclusions by laser Raman shift mapping, are shown below. Figure 6 The data points in the two are highly consistent. This intuitively demonstrates that the method provided in this application can accurately calculate the paleopressure values ​​of clastic gas reservoirs, which is more applicable and practical than previous methods. Furthermore, it can continuously calculate the paleopressure values ​​of various geological periods, and has certain industrial application value.

[0143] Example 3

[0144] This embodiment provides a paleopressure calculation device for clastic gas reservoirs, such as... Figure 7 The structural block diagram shown includes a fitting module 301, a first calculation module 302, a second calculation module 303, and a third calculation module 304, specifically as follows:

[0145] The fitting module 301 is used to obtain the discrete values ​​of rock formation compaction coefficient and porosity of rock samples in clastic rock formations under different effective stresses. The data fitting method is used to obtain the fitting relationship between the rock formation compaction coefficient and porosity.

[0146] In this embodiment, the discrete values ​​of the rock formation compaction coefficient and porosity of clastic rock samples from clastic rock formations under different effective stresses are obtained by testing the rock formation compaction coefficient and porosity of clastic rock samples from clastic rock formations under normal pressure and different confining pressures. The method for obtaining the rock formation compaction coefficient and porosity is as follows: the rock formation compaction coefficient and porosity are tested using the helium method with a PoroPDP-200 overburden porosity meter.

[0147] In this embodiment, the fitting module 301 includes a first fitting module, a second fitting module, and a relational merging module. The data fitting method is exemplified by the power-law fitting method, specifically:

[0148] The first fitting module is used to fit the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses using a power-law fitting method to obtain the fitting relationship between the rock formation compaction coefficient and the effective stress. The fitting relationship between the rock formation compaction coefficient and the effective stress is as follows:

[0149]

[0150] In the formula, C pc σ is the compaction coefficient of the rock formation; eff denoted as effective stress; α is the coefficient for fitting discrete values.

[0151] The second fitting module is used to fit the discrete values ​​of porosity of the clastic rock samples under different effective stresses using a power-law fitting method to obtain a fitting relationship between effective stress and porosity. The fitting relationship between effective stress and porosity is as follows:

[0152] σ eff =bφ c , (twenty four)

[0153] In the formula, σ eff φ represents the effective stress; φ represents the porosity; b and c are both discrete value fitting coefficients.

[0154] The first calculation module 302 is used to obtain the rock stratum compaction coefficient for any geological history time based on the porosity at any geological history time, through the fitting relationship between the rock stratum compaction coefficient and porosity.

[0155] In the embodiments of this application, the rock strata compaction coefficient C at any geological history time is described. pct The specific calculation formula is as follows:

[0156]

[0157] In the formula, φ tLet be the porosity at any given geological time t; a, b, and c are all discrete value fitting coefficients. The discrete value fitting coefficient 'a' can be obtained from the graph showing the change in the rock formation compaction coefficient of the clastic rock sample with increasing effective stress. The discrete value fitting coefficients 'b' and 'c' can be obtained from the correlation graph of effective stress and porosity of the clastic rock sample.

[0158] In this embodiment of the application, the porosity φ at any geological historical time t The depth-porosity index model can be used for calculation. The specific calculation formula for the depth-porosity index model is as follows:

[0159]

[0160] In the formula, φ0 is the measured porosity of the current clastic gas reservoir, which is an a priori value; e is the base of the natural logarithm, which is an a priori value; k is the compaction factor, which is an a priori value; H0 is the measured formation depth of the current clastic gas reservoir, which is an a priori value; H t H represents the stratigraphic depth at any given geological time t, wherein the functional relationship between any given geological time t and stratigraphic depth H can be obtained from the basin simulation burial depth-geological time evolution diagram.

[0161] The second calculation module 303 is used to determine the paleopore volume of any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time.

[0162] In this embodiment of the application, the second calculation module 303 includes an integration module and a fourth calculation module, wherein:

[0163] The integration module is used to perform integral transformation on the function of rock formation compaction coefficient with pore volume and confining pressure variation.

[0164] In this embodiment of the application, the function of the rock formation compaction coefficient with respect to pore volume and confining pressure variation is as follows:

[0165]

[0166] In the formula, C pc ΔP is the compaction coefficient of the rock formation. c V is the change in confining pressure. p ΔV represents the pore volume. p This represents the change in pore volume.

[0167] The integral transformation of both sides of the equation relating the compaction coefficient of the rock formation to the changes in pore volume and confining pressure yields the following function:

[0168]

[0169] In the formula, V p ρ is the pore volume; e is the base of the natural logarithm, a priori value; C pc P is the compaction coefficient of the rock formation. c d is the confining pressure; d is the integration constant.

[0170] In this embodiment, the integral constant d is obtained as follows: based on the discrete values ​​of the rock formation compaction coefficient and pore volume under arbitrary test confining pressure conditions, the integral constant d is calculated as a function of the rock formation compaction coefficient after integral transformation and the changes in pore volume and confining pressure. The specific calculation formula is as follows:

[0171] d=C pc1 ·P c1 -ln Vp1, (29)

[0172] In the formula, C pc1 To test the confining pressure P c1 Discrete values ​​of the formation compaction coefficient under the given conditions, V p1 To test the confining pressure P c1 Discrete values ​​of pore volume under certain conditions.

[0173] The fourth calculation module is used to calculate the paleopore volume for any geological time period based on the rock stratum compaction coefficient and confining pressure at any geological time period, using the rock stratum compaction coefficient after integral transformation as a function of the pore volume and the change in confining pressure.

[0174] In this embodiment of the application, the paleopore volume V at any geological historical time is... pt for:

[0175]

[0176] In the formula, e is the base of the natural logarithm, an a priori value; d is the integration constant; V pt C represents the pore volume at any geological time t. pct P is the formation compaction coefficient at any geological time t; ct Let t be the confining pressure at any given geological time t.

[0177] In this embodiment of the application, the confining pressure P at any geological history time t is... ct The method of obtaining the data is as follows: the confining pressure at any geological historical time is obtained according to the preset basin simulation burial depth-geological time evolution map.

[0178] Specifically:

[0179] P ct =P c0 +ρs (H t -H0), (31)

[0180] In the formula, P c0 The confining pressure of the current clastic gas reservoir; ρ s H represents the empirical value of shallow formation density; H0 represents the current formation depth of the clastic gas reservoir; H t H represents the stratigraphic depth at any given geological time t, wherein the functional relationship between any given geological time t and stratigraphic depth H can be obtained from the basin simulation burial depth-geological time evolution diagram.

[0181] The third calculation module 304 is used to determine the paleopressure of the formation at any geological history time based on the measured formation pressure, temperature and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any geological history time.

[0182] In this embodiment of the application, the third calculation module 304 is used to obtain the paleopressure of the formation at any geological history time based on the measured formation pressure, temperature and pore volume of the current clastic gas reservoir, as well as the paleotemperature and paleopore volume of the formation at any geological history time. Specifically, based on the ideal gas equation of state, and taking the measured formation pressure, temperature and pore volume of the current clastic gas reservoir as a starting point, the paleopressure of the formation at any geological history time is obtained based on the paleotemperature and paleopore volume of the formation at any geological history time.

[0183] In the embodiments of this application, the paleopressure P of the stratigraphy at any geological time t is... pt for:

[0184]

[0185] In the formula, P p0 T0 and V p0 V represents the measured formation pressure, geothermal temperature, and pore volume of the current clastic gas reservoir, which are a priori values; pt T represents the pore volume at any given geological time t; t Let T be the geothermal temperature at any given geological time t. Wherein, the formation temperature T at any given geological time t is... t It can be obtained from the temperature-geological time evolution diagram of the basin thermal history simulation.

[0186] Example 4

[0187] According to an embodiment of the present invention, an electronic device is also provided, including a storage device and a processor. The storage device stores a computer program, and when the processor executes the computer program, it implements the paleopressure calculation method for clastic gas reservoirs described in any of the above embodiments.

[0188] Example 5:

[0189] According to embodiments of the present invention, a storage medium is also provided, wherein a computer program stored in the storage medium is executable by one or more processors, and the computer program is used to implement the paleopressure calculation method for clastic gas reservoirs described in any of the above embodiments.

[0190] In summary, the method, apparatus, electronic equipment, and storage medium for calculating paleopressure in clastic gas reservoirs provided by this invention can accurately calculate the paleopressure values ​​of clastic gas reservoirs. Compared with previous methods, this invention has stronger applicability and practicality, and can continuously calculate the paleopressure values ​​of various geological periods, thus possessing certain industrial application value.

[0191] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0192] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of this application, the sequence numbers of the above-described processes do not imply a sequential 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. The sequence numbers of the above-described embodiments are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0193] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0194] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and 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. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0195] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units. They may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of this embodiment according to actual needs.

[0196] In addition, each functional unit in the various embodiments of this application can be integrated into one processing unit, or each unit can be a separate unit, or two or more units can be integrated into one unit; the integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0197] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.

[0198] Alternatively, if the integrated units described above are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a controller to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0199] The above description is merely an embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for calculating paleopressure in clastic gas reservoirs, characterized in that, include: Based on the discrete values ​​of rock compaction coefficient and porosity of clastic rock samples under different effective stresses, a data fitting method was used to obtain the fitting relationship between rock compaction coefficient and porosity. Based on the porosity at any geological time, the compaction coefficient of the rock formation at any geological time is obtained by fitting the relationship between the compaction coefficient and porosity. The paleopore volume for any given geological history time is determined based on the rock strata compaction coefficient and confining pressure at that time. The paleopressure of the formation at any given geological time is determined based on the measured formation pressure, temperature, and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any given geological time. The discrete values ​​of rock formation compaction coefficient and porosity of clastic rock samples under different effective stresses are used to obtain a fitting relationship between the rock formation compaction coefficient and porosity using a data fitting method. Specifically, this includes the following steps: Based on the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses, a power-law fitting method was used to fit the data and obtain the fitting relationship between the rock formation compaction coefficient and the effective stress. Based on the discrete values ​​of porosity of the clastic rock samples under different effective stresses, a power-law fitting method was used to fit the data and obtain the fitting relationship between effective stress and porosity. The fitting formulas for the compaction coefficient and effective stress of the rock formation and the fitting formulas for the effective stress and porosity are combined and transformed to obtain the fitting formula for the compaction coefficient and porosity of the rock formation.

2. The method according to claim 1, characterized in that, The porosity at any given geological time is calculated as follows: based on the measured formation depth of the clastic gas reservoir and the formation depth at any given geological time, the porosity at any given geological time is calculated using a depth-porosity relationship index model.

3. The method according to claim 1, characterized in that, The determination of the paleopore volume for any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time specifically includes the following steps: Integral transformation is performed on the function of compaction coefficient of rock formation with changes in pore volume and confining pressure; Based on the rock strata compaction coefficient and confining pressure at any given geological time, the paleopore volume at any given geological time is calculated using the rock strata compaction coefficient after integral transformation as a function of the changes in pore volume and confining pressure.

4. The method according to claim 1, characterized in that, The method for obtaining the confining pressure at any given geological time is as follows: the confining pressure at any given geological time is obtained based on a preset basin simulation burial depth-geological time evolution diagram.

5. The method according to claim 1, characterized in that, The specific formula for calculating the paleopore volume at any given geological time is as follows: ， In the formula, is the base of the natural logarithm; It is the integration constant; For any of the geological history times pore volume; For any of the geological history times The compaction coefficient of the rock formation; For any of the geological history times The confining pressure.

6. The method according to claim 5, characterized in that, The integral constant The method for obtaining the integral constant is as follows: based on the discrete values ​​of the rock formation compaction coefficient and pore volume under arbitrary test confining pressure conditions, the integral constant is calculated as a function of the rock formation compaction coefficient, pore volume, and change in confining pressure after integral transformation. .

7. A paleopressure calculation device for clastic gas reservoirs, characterized in that: include: The fitting module is used to obtain discrete values ​​of rock formation compaction coefficient and porosity of rock samples from clastic rock formations under different effective stresses. The data fitting method is used to obtain the fitting relationship between the rock formation compaction coefficient and porosity. The first calculation module is used to obtain the compaction coefficient of the rock strata at any geological history time based on the porosity at any geological history time, through the fitting relationship between the compaction coefficient of the rock strata and the porosity. The second calculation module is used to determine the paleopore volume of any geological history time based on the rock strata compaction coefficient and confining pressure at any geological history time. The third calculation module is used to determine the paleopressure of the formation at any geological time based on the measured formation pressure, temperature and pore volume of the clastic gas reservoir, as well as the paleotemperature and paleopore volume at any geological time. The fitting module is also used to fit the discrete values ​​of the rock formation compaction coefficient of the clastic rock samples under different effective stresses using a power-law fitting method to obtain a fitting relationship between the rock formation compaction coefficient and effective stress; to fit the discrete values ​​of the porosity of the clastic rock samples under different effective stresses using a power-law fitting method to obtain a fitting relationship between effective stress and porosity; and to merge and transform the fitting relationship between the rock formation compaction coefficient and effective stress and the fitting relationship between effective stress and porosity to obtain a fitting relationship between the rock formation compaction coefficient and porosity.

8. An electronic device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program that, when executed by the processor, performs the paleopressure calculation method for clastic gas reservoirs as described in any one of claims 1-6.

9. A storage medium, characterized in that: The computer program stored in the storage medium can be executed by one or more processors and can be used to implement the paleopressure calculation method for clastic gas reservoirs as described in any one of claims 1 to 6.

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