Method, apparatus, and storage medium for determining elastic moduli of tight sandstone reservoirs

Abstract

The application discloses a method and device for determining the elastic modulus of a tight sandstone reservoir and a storage medium, and comprises the following steps: determining the volume modulus of a corrected rock matrix and the shear modulus of the corrected rock matrix according to the connected porosity, the unconnected porosity and the determined volume modulus of the initial rock matrix; determining the rock framework volume modulus and the rock framework shear modulus according to the volume modulus of the corrected rock matrix, the shear modulus of the corrected rock matrix and the densification degree coefficient; obtaining the corresponding saturated rock of the target tight sandstone reservoir according to the water saturation, and determining the volume modulus of the gas-water mixed fluid; and determining the volume modulus of the saturated rock and the shear modulus of the saturated rock according to the connected porosity, the volume modulus of the corrected rock matrix, the volume modulus of the dry rock, the volume modulus of the gas-water mixed fluid and the rock framework shear modulus, so as to accurately detect the elastic modulus of the tight clastic rock reservoir and improve the accuracy of the shear wave prediction method.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of exploration, and particularly relates to a method for determining the elastic modulus of a tight sandstone reservoir, a device and a storage medium. BACKGROUND

[0002] There is a lack of shear wave velocity data in logging data, but the shear wave velocity data are very crucial for reservoir prediction, so the elastic modulus of a sandstone reservoir is obtained based on rock physical modeling technology, and then shear wave prediction is performed to obtain shear wave velocity prediction.

[0003] However, compared with conventional reservoirs, tight clastic reservoirs have the characteristics of low porosity, low permeability and poor connectivity. Therefore, the accuracy of the elastic modulus of the tight clastic reservoir obtained based on conventional rock physical modeling technology is low, which further reduces the accuracy of the shear wave prediction method. SUMMARY

[0004] The main purpose of the present application is to provide a method for determining the elastic modulus of a tight sandstone reservoir, a device and a storage medium, to solve the problem that the accuracy of the elastic modulus of a sandstone reservoir obtained based on conventional rock physical modeling technology is low, which further reduces the accuracy of the shear wave prediction method.

[0005] In view of the above problems, the present application provides a method for determining the elastic modulus of a tight sandstone reservoir, characterized in that it comprises:

[0006] obtaining the connected porosity, the unconnected porosity, the water saturation, the target mineral, the volume content of the target mineral and the densification degree coefficient of the target tight sandstone reservoir;

[0007] determining the bulk modulus of the initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral;

[0008] establishing micro-pores in the initial rock matrix according to the connected porosity and the unconnected porosity to obtain a modified rock matrix corresponding to the target tight sandstone reservoir, and determining the bulk modulus of the modified rock matrix and the shear modulus of the modified rock matrix based on the bulk modulus of the initial rock matrix;

[0009] determining the rock framework bulk modulus according to the bulk modulus of the modified rock matrix and the densification degree coefficient, and determining the rock framework shear modulus according to the shear modulus of the modified rock matrix and the densification degree coefficient;

[0010] filling the micro-pores of the rock framework with gas-water mixed fluid according to the water saturation to obtain a saturated rock corresponding to the target tight sandstone reservoir, and determining the bulk modulus of the gas-water mixed fluid;

[0011] determining a bulk modulus of the saturated rock according to the connected porosity, the bulk modulus of the modified rock matrix, the bulk modulus of the dry rock, the bulk modulus of the gas-water mixed fluid, and determining a shear modulus of the saturated rock according to the rock skeleton shear modulus.

[0012] Further, the method for determining the elastic modulus of the tight sandstone reservoir as described above further comprises:

[0013] determining a P-wave velocity and an S-wave velocity in the saturated rock corresponding to the target tight sandstone reservoir according to the bulk modulus of the saturated rock, the shear modulus of the saturated rock and a pre-acquired density of the saturated rock.

[0014] Further, in the method for determining the elastic modulus of the tight sandstone reservoir as described above, the micro-pores are established in the initial rock matrix according to the connected porosity and the unconnected porosity to obtain the modified rock matrix corresponding to the target tight sandstone reservoir, and the bulk modulus of the modified rock matrix and the shear modulus of the modified rock matrix are determined based on the bulk modulus of the initial rock matrix, comprising:

[0015] determining an initial P-wave velocity, an initial S-wave velocity and an initial density of the initial rock matrix based on the bulk modulus of the initial rock matrix;

[0016] determining a modified P-wave velocity of the modified rock matrix according to the initial P-wave velocity, the unconnected porosity and a pre-acquired P-wave velocity of a fluid in the unconnected pores, and determining a modified S-wave velocity of the modified rock matrix according to the initial S-wave velocity, the unconnected porosity, the initial density and a pre-acquired density of the fluid;

[0017] determining a compression modulus of the modified rock matrix and a shear modulus of the modified rock matrix according to the modified P-wave velocity, the modified S-wave velocity, the unconnected porosity, the density of the fluid and the initial density;

[0018] generating the bulk modulus of the modified rock matrix according to the compression modulus of the modified rock matrix.

[0019] Further, in the method for determining the elastic modulus of the tight sandstone reservoir as described above, the rock skeleton bulk modulus is determined, comprising:

[0020] determining the rock skeleton bulk modulus according to a pre-set rock skeleton bulk modulus calculation formula;

[0021] the rock skeleton bulk modulus calculation formula is:

[0022]

[0023] wherein, K dry represents the bulk modulus of the rock skeleton, K ma represents the bulk modulus of the modified rock matrix, represents the connected porosity, and Z represents the degree of compaction coefficient.

[0024] Further, in the method for determining the elastic modulus of the tight sandstone reservoir, the bulk modulus of the saturated rock is determined by comprising:

[0025] determining the bulk modulus of the saturated rock according to a preset bulk modulus calculation formula of the saturated rock;

[0026] the bulk modulus calculation formula of the saturated rock is:

[0027]

[0028] wherein, K sat represents the bulk modulus of the saturated rock, K f represents the bulk modulus of the gas-water mixed fluid, represents the connected porosity.

[0029] Further, in the method for determining the elastic modulus of the tight sandstone reservoir, the shear modulus of the rock skeleton is determined by comprising:

[0030] determining the shear modulus of the rock skeleton according to a preset shear modulus calculation formula of the rock skeleton;

[0031] the shear modulus calculation formula of the rock skeleton is:

[0032]

[0033] wherein, U dry represents the shear modulus of the rock skeleton, U ma represents the shear modulus of the modified rock matrix, represents the connected porosity, and Z represents the degree of compaction coefficient.

[0034] Further, in the method for determining the elastic modulus of the tight sandstone reservoir, the shear modulus of the saturated rock is determined by comprising:

[0035] determining the shear modulus of the saturated rock according to a preset shear modulus calculation formula of the saturated rock;

[0036] the shear modulus calculation formula of the saturated rock is:

[0037] U sat = U dry

[0038] wherein, U sat represents the shear modulus of the saturated rock.

[0039] Further, in the method for determining the elastic modulus of the tight sandstone reservoir, according to the water saturation, the gas-water mixed fluid is filled in the micro-pores of the rock skeleton to obtain the saturated rock corresponding to the target tight sandstone reservoir, and the bulk modulus of the gas-water mixed fluid is determined, including:

[0040] According to the water saturation, the proportion coefficient between the gas and the water is determined.

[0041] According to the proportion coefficient between the gas and the water, the gas-water mixed fluid is filled in the micro-pores of the dry rock to obtain the saturated rock corresponding to the target tight sandstone reservoir.

[0042] According to a preset bulk modulus calculation formula of the gas-water mixed fluid, the bulk modulus of the gas-water mixed fluid is determined.

[0043] The bulk modulus calculation formula of the gas-water mixed fluid is:

[0044]

[0045] wherein, S Hc represents the gas saturation in the connected pores, represents the total connected porosity, represents the connected porosity, represents the unconnected porosity, S wc represents the water saturation in the connected pores, K f represents the bulk modulus of the gas-water mixed fluid.

[0046] The application further provides a detection device for the elastic modulus of a tight sandstone reservoir, including a memory and a processor.

[0047] The memory stores a computer program, and the computer program is executed by the processor to realize the steps of the method for determining the elastic modulus of the tight sandstone reservoir.

[0048] The application further provides a storage medium, which stores a computer program, and the computer program is executed by the processor to realize the steps of the method for determining the elastic modulus of the tight sandstone reservoir.

[0049] Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:

[0050] The method, device and storage medium for determining the elastic modulus of the tight sandstone reservoir of the application firstly introduce the unconnected porosity, correct the volume modulus of the initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral, obtain the volume modulus of the corrected rock matrix and the shear modulus of the corrected rock matrix, secondly determine the rock framework volume modulus according to the volume modulus of the corrected rock matrix and the tightness degree coefficient, and determine the rock framework shear modulus according to the shear modulus of the corrected rock matrix and the tightness degree coefficient, and then determine the volume modulus of the saturated rock according to the connected porosity, the volume modulus of the corrected rock matrix, the volume modulus of the dry rock, the volume modulus of the obtained gas-water mixed fluid, and determine the shear modulus of the saturated rock according to the rock framework shear modulus. The technical scheme of the application can accurately detect the elastic modulus of the tight clastic rock reservoir, thereby improving the accuracy of the shear wave prediction method.

[0051] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0052] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0053] Figure 1 Flow chart of the method for determining the elastic modulus of the tight sandstone reservoir of the application;

[0054] Figure 2 Schematic diagram of the prediction result obtained by using the technical scheme of the application;

[0055] Figure 3 Schematic diagram of the prediction result obtained by using the conventional method;

[0056] Figure 4 Structure schematic diagram of the detection device for the elastic modulus of the tight sandstone reservoir of the application;

[0057] Figure 5 Structure schematic diagram of the detection device for the elastic modulus of the tight sandstone reservoir of the application. DETAILED DESCRIPTION

[0058] The embodiments of the present application will be described in detail below with reference to the accompanying drawings and embodiments, so that how the present application applies technical means to solve technical problems and achieves technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present application.

[0059] Example One

[0060] To solve the above technical problems in the prior art, the embodiments of the present application provide a method for determining the elastic modulus of a tight sandstone reservoir.

[0061] Figure 1 The flowchart of the method for determining the elastic modulus of a tight sandstone reservoir according to the embodiments of the present application is shown in FIG. 1, and the method for determining the elastic modulus of a tight sandstone reservoir according to the embodiments of the present application can specifically include the following steps: Figure 1

[0062] 100, obtaining the connected porosity, unconnected porosity, water saturation, target mineral, volume content of the target mineral and densification degree coefficient of the target tight sandstone reservoir;

[0063] In a specific implementation process, the logging curve of the target tight sandstone reservoir can be obtained; and the connected porosity, unconnected porosity, water saturation, target mineral, volume content of the target mineral and densification degree coefficient of the target tight sandstone reservoir can be determined according to the logging curve.

[0064] Specifically, the logging curve of the target tight sandstone reservoir can be obtained. The logging curve can include gamma, natural potential, caliper, density, neutron porosity, acoustic wave, deep and shallow resistivity and the like. The target mineral and volume content of the target mineral as well as porosity and water saturation can be calculated based on the logging curve by using the optimal logging interpretation technology. Specifically, the main mineral composition (i.e. the target mineral) of the target tight sandstone reservoir can be determined based on the whole rock analysis technology, and then the volume content of the target mineral as well as porosity and water saturation can be calculated based on the optimal logging interpretation technology. In this way, the density, connected porosity, water saturation, target mineral and volume content of the target mineral of the target tight sandstone reservoir can be obtained.

[0065] ​The water saturation can refer to the ratio of the volume of pores occupied by water in the reservoir to the volume of rock pores. The connected porosity can refer to the ratio of the sum of the volume of all pore spaces in the rock sample to the volume of the rock sample, expressed in percentage. The target mineral can refer to the main mineral in the target tight sandstone reservoir, for example, a mineral with a large proportion in the reservoir. The volume content of the target mineral can refer to the percentage of the volume of the target mineral to the total volume of the rock. The target mineral can include quartz, clay, feldspar, calcite, and the like.

[0066] In a specific implementation process, the simulated annealing method can be used to determine the unconnected porosity and the compaction degree coefficient. The compaction degree coefficient is a parameter Z obtained by considering the influence of the consolidation characteristics (compaction degree) and the shape of the pores on the overall embodiment.

[0067] Specifically, the difference between the measured P-wave velocity and the predicted P-wave velocity of the saturated rock is taken as the system energy of the simulated annealing method. By iteratively searching for the numerical optimal solution of the unconnected porosity and the compaction degree coefficient in a given range, the system energy in the simulated annealing method is minimized, and the unconnected porosity and the compaction degree coefficient obtained at this time are the estimation results of the two parameters. The estimation results are substituted back to obtain the unconnected porosity and the compaction degree coefficient.

[0068] In a specific implementation process, the step of determining the unconnected porosity and the compaction degree coefficient by using the simulated annealing method can include the following steps:

[0069] (1) Selecting the search range of the unconnected porosity and the search range of the compaction degree coefficient.

[0070] (2) Initializing the unconnected porosity and the compaction degree coefficient, and calculating the P-wave and S-wave velocity prediction value of the current unconnected porosity and the compaction degree coefficient according to the method for determining the elastic modulus of the tight sandstone reservoir.

[0071] (3) In each iteration of the simulated annealing algorithm, the following calculations are performed:

[0072] a) Updating the unconnected porosity and the compaction degree coefficient, and calculating the P-wave and S-wave velocity prediction value of the current unconnected porosity and the compaction degree coefficient;

[0073] b) Determining whether to accept the updated unconnected porosity and the compaction degree coefficient by using the acceptance criterion in the simulated annealing algorithm;

[0074] c) Calculating the system energy J, and if the system energy J is greater than the termination iteration threshold or the number of iterations has not reached the maximum number of iterations, returning to step a);

[0075] (4) after convergence in step (3), obtaining the unconnected porosity and the densification degree coefficient.

[0076] 101. determining the initial rock matrix volume modulus corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral;

[0077] In one specific implementation process, the target mineral can be equivalent by using the V-R-H average formula according to the target mineral and the volume content of the target mineral, so as to obtain the volume modulus of the rock matrix corresponding to the target tight sandstone reservoir.

[0078] Specifically, the target mineral can be equivalent by using the V-R-H average formula (1) according to the target mineral and the volume content of the target mineral, so as to obtain the volume modulus of the rock matrix corresponding to the target tight sandstone reservoir. Wherein, the V-R-H average formula (1) is used to obtain the volume modulus of the rock matrix:

[0079]

[0080] Wherein, M VRh is the volume modulus of the initial rock matrix, M V is the upper boundary volume modulus obtained by using the Voigt model, and M R is the lower boundary volume modulus obtained by using the Reuss model. In the above manner, the main minerals constituting the rock can be equivalent by using the V-R-H average formula, so as to obtain the volume modulus of the initial rock matrix and the shear modulus of the initial rock matrix.

[0081] 102. establishing micro-pores in the initial rock matrix according to the connected porosity and the unconnected porosity, obtaining the modified rock matrix corresponding to the target tight sandstone reservoir, and determining the volume modulus of the modified rock matrix and the shear modulus of the modified rock matrix based on the volume modulus of the initial rock matrix;

[0082] In one specific implementation process, the volume modulus of the modified rock matrix and the shear modulus of the modified rock matrix can be determined according to the following steps:

[0083] (11) determining the initial longitudinal wave velocity, the initial transverse wave velocity and the initial density of the initial rock matrix based on the volume modulus of the initial rock matrix;

[0084] Specifically, the initial longitudinal wave velocity, the initial transverse wave velocity and the initial density of the initial rock matrix can be obtained by using the volume modulus of the initial rock matrix according to the existing related technology, which will not be described here.

[0085] (12) determining a corrected P-wave velocity of the corrected rock matrix according to the initial P-wave velocity, the unconnected porosity and a P-wave velocity of a fluid in the unconnected porosity previously acquired, and determining a corrected S-wave velocity of the corrected rock matrix according to the initial S-wave velocity, the unconnected porosity, the initial density and a density of the fluid previously acquired;

[0086] Specifically, the initial P-wave velocity, the unconnected porosity and the P-wave velocity of the fluid in the unconnected porosity previously acquired can be substituted into a preset corrected P-wave velocity calculation formula (2) to obtain the corrected P-wave velocity of the corrected rock matrix.

[0087]

[0088] wherein v PS represents the corrected P-wave velocity of the corrected rock matrix, represents the unconnected porosity, v Pm represents the initial P-wave velocity, v Pf represents the P-wave velocity of the fluid in the unconnected porosity.

[0089] The initial S-wave velocity, the unconnected porosity, the initial density and the density of the fluid previously acquired can be substituted into a preset corrected S-wave velocity calculation formula (3) to obtain the corrected S-wave velocity of the corrected rock matrix.

[0090]

[0091] wherein v SS represents the corrected S-wave velocity of the corrected rock matrix, p m represents the initial density, v Sm represents the initial S-wave velocity, p n represents the density of the fluid.

[0092] (13) determining a compression modulus of the corrected rock matrix and a shear modulus of the corrected rock matrix according to the corrected P-wave velocity, the corrected S-wave velocity, the unconnected porosity, the density of the fluid and the initial density;

[0093] Specifically, the corrected S-wave velocity can be substituted into a preset shear modulus calculation formula (4) of the corrected rock matrix to obtain the shear modulus of the corrected rock matrix.

[0094]

[0095] wherein U s represents the shear modulus of the corrected rock matrix, p ms represents the density of the corrected rock matrix.

[0096] The corrected longitudinal wave velocity, the corrected shear modulus of the rock matrix, the unconnected porosity, the density of the fluid, and the initial density can be substituted into a preset compression modulus calculation formula (5) of the corrected rock matrix to obtain a compression modulus of the corrected rock matrix.

[0097]

[0098] wherein, C s represents the compression modulus of the corrected rock matrix.

[0099] (14) generating a bulk modulus of the corrected rock matrix according to the compression modulus of the corrected rock matrix.

[0100] Specifically, the compression modulus of the corrected rock matrix can be substituted into a preset bulk modulus calculation formula (6) of the corrected rock matrix to generate a bulk modulus of the corrected rock matrix.

[0101]

[0102] wherein, K m represents the compression modulus of the corrected rock matrix.

[0103] 103. determining a rock skeleton bulk modulus according to the bulk modulus of the corrected rock matrix and the degree of compaction coefficient, and determining a rock skeleton shear modulus according to the shear modulus of the corrected rock matrix and the degree of compaction coefficient;

[0104] In one specific implementation process, the rock skeleton bulk modulus can be determined according to a preset rock skeleton bulk modulus calculation formula.

[0105] The rock skeleton bulk modulus calculation formula (7) is:

[0106]

[0107] wherein, K dry represents the rock skeleton bulk modulus, K ma represents the bulk modulus of the corrected rock matrix, represents the connected porosity, and Z represents the degree of compaction coefficient.

[0108] The rock skeleton shear modulus can be determined according to a preset rock skeleton shear modulus calculation formula.

[0109] The rock skeleton shear modulus calculation formula (8) is:

[0110]

[0111] wherein, U drydenotes the shear modulus of the rock skeleton, U ma denotes the shear modulus of the modified rock matrix, denotes the connected porosity, Z denotes the densification degree coefficient.

[0112] 104. According to the water saturation, filling the gas-water mixed fluid in the micro-pore of the rock skeleton to obtain the saturated rock corresponding to the target tight sandstone reservoir, and determining the bulk modulus of the gas-water mixed fluid;

[0113] In one specific implementation process, according to the water saturation, the proportion coefficient between gas and water can be determined; according to the proportion coefficient between gas and water, the gas-water mixed fluid is filled in the micro-pore of the dry rock to obtain the saturated rock corresponding to the target tight sandstone reservoir; and according to the preset bulk modulus calculation formula of the gas-water mixed fluid, the bulk modulus of the gas-water mixed fluid is determined.

[0114] Specifically, the bulk modulus calculation formula (9) of the gas-water mixed fluid is:

[0115]

[0116] wherein, S Hc denotes the gas saturation in the connected pore, denotes the total connected porosity, denotes the connected porosity, denotes the unconnected porosity, S wc denotes the water saturation in the connected pore, K f denotes the bulk modulus of the gas-water mixed fluid.

[0117] 105. According to the connected porosity, the bulk modulus of the modified rock matrix, the bulk modulus of the dry rock, and the bulk modulus of the gas-water mixed fluid, the bulk modulus of the saturated rock is determined, and according to the shear modulus of the rock skeleton, the shear modulus of the saturated rock is determined.

[0118] In one specific implementation process, the bulk modulus of the saturated rock can be determined according to the preset bulk modulus calculation formula (10) of the saturated rock;

[0119] The bulk modulus calculation formula (10) of the saturated rock is:

[0120]

[0121] wherein, K sat denotes the bulk modulus of the saturated rock, K f denotes the bulk modulus of the gas-water mixed fluid, denotes the connected porosity.

[0122] The shear modulus of the saturated rock can be determined according to a preset shear modulus calculation formula (11) of the saturated rock.

[0123] The shear modulus calculation formula (11) of the saturated rock is:

[0124] U sat =U dry (11)

[0125] Wherein, U sat represents the shear modulus of the saturated rock.

[0126] The method for determining the elastic modulus of the compacted sandstone reservoir in the embodiment first introduces the unconnected porosity, corrects the volume modulus of the initial rock matrix corresponding to the target compacted sandstone reservoir according to the target mineral and the volume content of the target mineral, obtains the volume modulus of the corrected rock matrix and the shear modulus of the corrected rock matrix, secondly determines the rock framework volume modulus according to the volume modulus of the corrected rock matrix and the compactification degree coefficient, and determines the rock framework shear modulus according to the shear modulus of the corrected rock matrix and the compactification degree coefficient, then determines the volume modulus of the saturated rock according to the connected porosity, the volume modulus of the corrected rock matrix, the volume modulus of the dry rock, and the volume modulus of the obtained gas-water mixed fluid, and determines the shear modulus of the saturated rock according to the rock framework shear modulus. The technical solution of the present application can accurately detect the elastic modulus of the compacted clastic rock reservoir, and further improve the accuracy of the shear wave prediction method.

[0127] In one specific implementation process, after the volume modulus of the saturated rock and the shear modulus of the saturated rock are determined, the longitudinal wave velocity and the transverse wave velocity in the saturated rock corresponding to the target compacted sandstone reservoir can be determined according to the volume modulus of the saturated rock, the shear modulus of the saturated rock, and the density of the saturated rock obtained in advance.

[0128] Specifically, the longitudinal wave velocity in the saturated rock can be calculated according to a preset longitudinal wave velocity calculation formula (12) of the saturated rock.

[0129]

[0130] Wherein, VP sat represents the longitudinal wave velocity of the saturated rock, ρ sat represents the density of the saturated rock, ρ f represents the density of the gas-water mixed fluid, ρ W represents the density of water, and ρ f represents the density of gas.

[0131] It should be noted that the method of the embodiment of the present application can be executed by a single device, such as a computer or a server. The method of the embodiment can also be applied to a distributed scenario, and be completed by multiple devices cooperating with each other. In the distributed scenario, one of the multiple devices can only execute one or more steps in the method of the embodiment of the present application, and the multiple devices can interact with each other to complete the method.

[0132] Example Two

[0133] In a specific implementation process, the method for determining the elastic modulus of the tight sandstone reservoir in the text application is tested by using actual data. The actual data includes the measured P-wave velocity, S-wave velocity and density curve, which can be used as a reference for the prediction result. The closer to the measured result, the more accurate the model is.

[0134] Figure 2 The prediction result obtained by using the technical scheme of the present application is shown in the following figure, Figure 2 In the figure, from top to bottom are the curves of the P-wave velocity of the saturated rock, the S-wave velocity of the saturated rock and the density of the saturated rock, which are the prediction results, and the dotted line is the measured result. The abscissa is the sampling depth, and the ordinate is the amplitude.

[0135] Figure 3 The prediction result obtained by using the conventional method is shown in the following figure, Figure 3 In the figure, from top to bottom are the curves of the P-wave velocity of the saturated rock, the S-wave velocity of the saturated rock and the density of the saturated rock, which are the prediction results, and the dotted line is the measured result. The abscissa is the sampling depth, and the ordinate is the amplitude.

[0136] By comparing Figure 2 and Figure 3 , it can be seen that Figure 2 the curves of the P-wave velocity of the saturated rock, the S-wave velocity of the saturated rock and the density of the saturated rock in the prediction result are more consistent with the curves of the P-wave velocity of the saturated rock, the S-wave velocity of the saturated rock and the density of the saturated rock in the measured result. Therefore, by using the technical scheme of the present application, the elastic modulus of the tight clastic rock reservoir can be accurately detected, and the accuracy of the S-wave prediction method is improved.

[0137] Example Three

[0138] To solve the above technical problems in the prior art, an embodiment of the present application provides a device for detecting the elastic modulus of a tight sandstone reservoir.

[0139] Figure 4 The structure diagram of the device for detecting the elastic modulus of the tight sandstone reservoir according to the embodiment of the present application is shown in the following figure. Figure 4As shown, the device for detecting the elastic modulus of the tight sandstone reservoir in the embodiment can include an acquisition module 40, a first determination module 41, a second determination module 42, a third determination module 43, a fourth determination module 44, and a fifth determination module 45.

[0140] The acquisition module 40 is configured to acquire the connected porosity, the unconnected porosity, the water saturation, the target mineral, the volume content of the target mineral, and the compaction degree coefficient of the target tight sandstone reservoir.

[0141] In a specific implementation process, the logging curves of the target tight sandstone reservoir can be acquired; and the connected porosity, the unconnected porosity, the water saturation, the target mineral, the volume content of the target mineral, and the compaction degree coefficient of the target tight sandstone reservoir can be determined according to the logging curves.

[0142] Specifically, the logging curves of the target tight sandstone reservoir can be acquired. The logging curves can include gamma, natural potential, caliper, density, neutron porosity, acoustic wave, and deep-shallow resistivity curves. The target mineral and the volume content of the target mineral, as well as the porosity and the water saturation, can be calculated based on the logging curves by using the optimal logging interpretation technology. Specifically, the main mineral composition (i.e., the target mineral) of the target tight sandstone reservoir can be determined based on the whole rock analysis technology, and then the volume content of the target mineral, as well as the porosity and the water saturation, can be calculated based on the optimal logging interpretation technology. In this way, the density, the connected porosity, the water saturation, the target mineral, and the volume content of the target mineral of the target tight sandstone reservoir can be acquired.

[0143] The water saturation can refer to the ratio of the volume of the pores occupied by water to the volume of the pores of the rock in the reservoir. The connected porosity can refer to the ratio of the sum of the volumes of all pore spaces in the rock sample to the volume of the rock sample, expressed in percentage. The target mineral can refer to the main mineral in the target tight sandstone reservoir, for example, a mineral with a large proportion in the reservoir. The volume content of the target mineral can refer to the percentage of the volume of the target mineral to the total volume of the rock. The target mineral can include quartz, clay, feldspar, calcite, and the like.

[0144] In a specific implementation process, the simulated annealing method can be used to determine the unconnected porosity and the compaction degree coefficient. The compaction degree coefficient is a parameter Z obtained by considering the consolidation characteristics (compaction degree) and the shape of the pores and the like.

[0145] Specifically, the difference between the measured P-wave velocity and the predicted P-wave velocity of the saturated rock is taken as the system energy of the simulated annealing method; by iteratively searching for the numerical optimal solution of the unconnected porosity and the densification degree coefficient within a given range, the system energy in the simulated annealing method is minimized, and the unconnected porosity and the densification degree coefficient obtained at this time are the estimation results of the two parameters. The estimation results are substituted back to obtain the unconnected porosity and the densification degree coefficient.

[0146] In a specific implementation process, the step of determining the unconnected porosity and the densification degree coefficient by using the simulated annealing method can include the following steps:

[0147] (1) Select the search range of the unconnected porosity and the search range of the densification degree coefficient.

[0148] (2) Initialize the unconnected porosity and the densification degree coefficient, and calculate the P-S wave velocity prediction value of the current unconnected porosity and the densification degree coefficient according to the method for determining the elastic modulus of the tight sandstone reservoir.

[0149] (3) In each iteration of the simulated annealing algorithm, the following calculations are performed:

[0150] a) Update the unconnected porosity and the densification degree coefficient, and calculate the P-S wave velocity prediction value of the current unconnected porosity and the densification degree coefficient;

[0151] b) Determine whether to accept the updated unconnected porosity and the densification degree coefficient by using the acceptance criterion in the simulated annealing algorithm;

[0152] c) Calculate the system energy J, and if the system energy J is greater than the termination iteration threshold or the number of iterations has not reached the maximum number of iterations, return to step a);

[0153] (4) After step (3) converges, the unconnected porosity and the densification degree coefficient are obtained.

[0154] The first determination module 41 is configured to determine the bulk modulus of the initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral.

[0155] In a specific implementation process, the V-R-H average formula can be used to equivalently process the target mineral according to the target mineral and the volume content of the target mineral, so as to obtain the bulk modulus of the rock matrix corresponding to the target tight sandstone reservoir.

[0156] Specifically, the V-R-H average formula (1) can be used to equivalently process the target mineral according to the target mineral and the volume content of the target mineral, so as to obtain the bulk modulus of the rock matrix corresponding to the target tight sandstone reservoir.

[0157] The V-R-H average formula (1) can be found in the above description and will not be repeated here.

[0158] The second determining module 42 is configured to establish micro-pores in the initial rock matrix according to the connected porosity and the unconnected porosity to obtain a modified rock matrix corresponding to the target tight sandstone reservoir, and determine the bulk modulus of the modified rock matrix and the shear modulus of the modified rock matrix based on the bulk modulus of the initial rock matrix.

[0159] Specifically, the second determining module 42 can determine the bulk modulus of the modified rock matrix and the shear modulus of the modified rock matrix according to the following steps:

[0160] (11) Determine the initial P-wave velocity, the initial S-wave velocity and the initial density of the initial rock matrix based on the bulk modulus of the initial rock matrix.

[0161] (12) Determine the modified P-wave velocity of the modified rock matrix according to the initial P-wave velocity, the unconnected porosity and the P-wave velocity of the fluid in the unconnected pores obtained in advance, and determine the modified S-wave velocity of the modified rock matrix according to the initial S-wave velocity, the unconnected porosity, the initial density and the density of the fluid obtained in advance.

[0162] (13) Determine the compression modulus of the modified rock matrix and the shear modulus of the modified rock matrix according to the modified P-wave velocity, the modified S-wave velocity, the unconnected porosity, the density of the fluid and the initial density.

[0163] (14) Generate the bulk modulus of the modified rock matrix according to the compression modulus of the modified rock matrix.

[0164] The third determining module 43 is configured to determine the rock framework bulk modulus according to the bulk modulus of the modified rock matrix and the densification degree coefficient, and determine the rock framework shear modulus according to the shear modulus of the modified rock matrix and the densification degree coefficient.

[0165] In one specific implementation process, the rock framework bulk modulus can be determined according to the preset rock framework bulk modulus calculation formula (7). The rock framework shear modulus can be determined according to the preset rock framework shear modulus calculation formula (8).

[0166] The rock framework bulk modulus calculation formula (7) and the rock framework shear modulus calculation formula (8) can be found in the above description and will not be repeated here.

[0167] The fourth determining module 44 is configured to fill the gas-water mixed fluid in the micro-pore of the rock skeleton according to the water saturation, to obtain the saturated rock corresponding to the target tight sandstone reservoir, and to determine the bulk modulus of the gas-water mixed fluid.

[0168] In a specific implementation process, the proportion coefficient between the gas and the water can be determined according to the water saturation; the gas-water mixed fluid is filled in the micro-pore of the dry rock according to the proportion coefficient between the gas and the water, to obtain the saturated rock corresponding to the target tight sandstone reservoir; and the bulk modulus of the gas-water mixed fluid is determined according to the preset bulk modulus calculation formula (9) of the gas-water mixed fluid.

[0169] The bulk modulus calculation formula (9) of the gas-water mixed fluid can refer to the description above, and will not be described here again.

[0170] The fifth determining module 45 is configured to determine the bulk modulus of the saturated rock according to the connected porosity, the bulk modulus of the corrected rock matrix, the bulk modulus of the dry rock, and the bulk modulus of the gas-water mixed fluid, and to determine the shear modulus of the saturated rock according to the shear modulus of the rock skeleton.

[0171] In a specific implementation process, the bulk modulus of the saturated rock can be determined according to the preset bulk modulus calculation formula (10) of the saturated rock; and the shear modulus of the saturated rock can be determined according to the preset shear modulus calculation formula (11) of the saturated rock.

[0172] The bulk modulus calculation formula (10) of the saturated rock and the shear modulus calculation formula (11) of the saturated rock can refer to the description above, and will not be described here again.

[0173] The device for detecting the elastic modulus of the tight sandstone reservoir in the embodiment first introduces the unconnected porosity, corrects the bulk modulus of the initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral, to obtain the bulk modulus and the shear modulus of the corrected rock matrix, then determines the bulk modulus of the rock skeleton according to the bulk modulus of the corrected rock matrix and the compactification degree coefficient, and determines the shear modulus of the rock skeleton according to the shear modulus of the corrected rock matrix and the compactification degree coefficient, and finally determines the bulk modulus of the saturated rock according to the connected porosity, the bulk modulus of the corrected rock matrix, the bulk modulus of the dry rock, and the bulk modulus of the gas-water mixed fluid obtained, and determines the shear modulus of the saturated rock according to the shear modulus of the rock skeleton. The technical solution of the device can accurately detect the elastic modulus of the tight clastic rock reservoir, and further improve the accuracy of the shear wave prediction method.

[0174] In a specific implementation process, the device for detecting the elastic modulus of the tight sandstone reservoir can further include a sixth determining module (not shown in the figure).

[0175] The sixth determining module is configured to, after the fifth determining module 45 determines the bulk modulus of the saturated rock and the shear modulus of the saturated rock, determine the longitudinal wave velocity and the transverse wave velocity in the saturated rock corresponding to the target tight sandstone reservoir according to the bulk modulus of the saturated rock, the shear modulus of the saturated rock, and the density of the saturated rock obtained in advance.

[0176] The device of the above-mentioned embodiments is used to implement the corresponding method in the above-mentioned embodiments, and the specific implementation scheme can refer to the related description in the method and the method embodiments of the above-mentioned embodiments, and has the beneficial effects of the corresponding method embodiments, which will not be described here.

[0177] Example Four

[0178] To solve the above technical problems existing in the prior art, the embodiments of the present application provide a device for detecting organic-rich shale clay distribution information.

[0179] Figure 5 For the structural schematic diagram of the embodiment of the present application for detecting the elastic modulus of the tight sandstone reservoir, as shown in Figure 5 The device can include a processor 1010, a memory 1020, as known by those skilled in the art. The device can also include an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 for internal communication within the device.

[0180] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, etc., for executing related programs to implement the technical solutions provided by the embodiments of the present application.

[0181] The memory 1020 can be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, etc. The memory 1020 can store an operating system and other application programs, and when the technical solutions provided by the embodiments of the present specification are implemented by software or firmware, the related program codes are saved in the memory 1020 and are called and executed by the processor 1010.

[0182] The input / output interface 1030 is configured to connect an input / output module to realize information input and output. The input / output module can be configured as a component in the device (not shown in the figure) or can be externally connected to the device to provide corresponding functions. The input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device can include a display, a speaker, a vibrator, an indicator light, etc.

[0183] The communication interface 1040 is configured to connect a communication module (not shown in the figure) to realize the communication interaction between the device and other devices. The communication module can realize communication through a wired manner (such as a USB, a network cable, etc.) or through a wireless manner (such as a mobile network, WIFI, Bluetooth, etc.).

[0184] The bus 1050 includes a channel for transmitting information between various components (such as the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040) of the device.

[0185] It should be noted that although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040, and the bus 1050, in the specific implementation process, the device can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only contain the components necessary to implement the solutions of the embodiments of the present specification, and does not have to contain all the components shown in the figure.

[0186] The detection device for the elastic modulus of the tight sandstone reservoir provided by the embodiments of the present application has a computer program stored on the memory, and the computer program is executed by the processor to implement the following steps:

[0187] The connected porosity, the unconnected porosity, the water saturation, the target mineral, the volume content of the target mineral, and the densification degree coefficient of the target tight sandstone reservoir are obtained.

[0188] According to the target mineral and the volume content of the target mineral, the volume modulus of the initial rock matrix corresponding to the target tight sandstone reservoir is determined.

[0189] According to the connected porosity and the unconnected porosity, micro-pores are established in the initial rock matrix to obtain a modified rock matrix corresponding to the target tight sandstone reservoir, and a bulk modulus of the modified rock matrix and a shear modulus of the modified rock matrix are determined based on a bulk modulus of the initial rock matrix;

[0190] According to the bulk modulus of the modified rock matrix and the densification degree coefficient, a rock skeleton bulk modulus is determined, and according to the shear modulus of the modified rock matrix and the densification degree coefficient, a rock skeleton shear modulus is determined;

[0191] According to the water saturation, gas-water mixed fluid is filled in the micro-pores of the rock skeleton to obtain a saturated rock corresponding to the target tight sandstone reservoir, and a bulk modulus of the gas-water mixed fluid is determined;

[0192] According to the connected porosity, the bulk modulus of the modified rock matrix, the bulk modulus of the dry rock, and the bulk modulus of the gas-water mixed fluid, a bulk modulus of the saturated rock is determined, and according to the rock skeleton shear modulus, a shear modulus of the saturated rock is determined.

[0193] Further, the computer program, when executed by the processor, can further implement the following steps:

[0194] According to the bulk modulus of the saturated rock, the shear modulus of the saturated rock, and a density of the saturated rock obtained in advance, a longitudinal wave velocity and a transverse wave velocity in the saturated rock corresponding to the target tight sandstone reservoir are determined.

[0195] Further, the computer program, when executed by the processor, can further implement the following steps:

[0196] Based on the bulk modulus of the initial rock matrix, an initial longitudinal wave velocity, an initial transverse wave velocity, and an initial density of the initial rock matrix are determined;

[0197] According to the initial longitudinal wave velocity, the unconnected porosity, and a longitudinal wave velocity of fluid in the unconnected pores obtained in advance, a modified longitudinal wave velocity of the modified rock matrix is determined, and according to the initial transverse wave velocity, the unconnected porosity, the initial density, and a density of the fluid obtained in advance, a modified transverse wave velocity of the modified rock matrix is determined;

[0198] According to the modified longitudinal wave velocity, the modified transverse wave velocity, the unconnected porosity, the density of the fluid, and the initial density, a compression modulus of the modified rock matrix and a shear modulus of the modified rock matrix are determined;

[0199] generate a bulk modulus of the modified rock matrix according to the modified compression modulus of the rock matrix.

[0200] Further, the computer program, when executed by the processor, can further implement the following steps:

[0201] determine a bulk modulus of the rock skeleton according to a preset bulk modulus calculation formula of the rock skeleton;

[0202] The bulk modulus calculation formula of the rock skeleton is:

[0203]

[0204] wherein, K dry represents the bulk modulus of the rock skeleton, K ma represents the bulk modulus of the modified rock matrix, represents the connected porosity, and Z represents the densification degree coefficient.

[0205] Further, the computer program, when executed by the processor, can further implement the following steps:

[0206] determine a bulk modulus of the saturated rock according to a preset bulk modulus calculation formula of the saturated rock;

[0207] The bulk modulus calculation formula of the saturated rock is:

[0208]

[0209] wherein, K sat represents the bulk modulus of the saturated rock, K f represents the bulk modulus of the gas-water mixed fluid, represents the connected porosity.

[0210] Further, the computer program, when executed by the processor, can further implement the following steps:

[0211] determine a shear modulus of the rock skeleton according to a preset shear modulus calculation formula of the rock skeleton;

[0212] The shear modulus calculation formula of the rock skeleton is:

[0213]

[0214] wherein, U dry represents the shear modulus of the rock skeleton, U ma represents the shear modulus of the modified rock matrix, represents the connected porosity, and Z represents the densification degree coefficient.

[0215] Further, in the above embodiment, the computer program, when executed by the processor, can further implement the following steps:

[0216] According to a preset shear modulus calculation formula of the saturated rock, a shear modulus of the saturated rock is determined.

[0217] The shear modulus calculation formula of the saturated rock is:

[0218] U sat = U dry

[0219] Wherein, U sat represents the shear modulus of the saturated rock.

[0220] Further, in the above embodiment, the computer program, when executed by the processor, can further implement the following steps:

[0221] According to the water saturation, a proportionality coefficient between gas and water is determined.

[0222] According to the proportionality coefficient between gas and water, a gas-water mixed fluid is filled in the micro-pore of the dry rock, so as to obtain a saturated rock corresponding to the target tight sandstone reservoir.

[0223] According to a preset bulk modulus calculation formula of the gas-water mixed fluid, a bulk modulus of the gas-water mixed fluid is determined.

[0224] The bulk modulus calculation formula of the gas-water mixed fluid is:

[0225]

[0226] Wherein, S Hc represents the gas saturation in the connected pore, represents the total connected porosity, represents the connected porosity, represents the unconnected porosity, S wc represents the water saturation in the connected pore, K f represents the bulk modulus of the gas-water mixed fluid.

[0227] Example Five

[0228] To solve the above technical problems in the prior art, an embodiment of the present application provides a storage medium.

[0229] The storage medium provided by the embodiment of the present application has a computer program stored thereon, and the computer program, when executed by a processor, implements the following steps.

[0230] obtaining a connected porosity, an unconnected porosity, a water saturation, a target mineral, a volume content of the target mineral, and a densification degree coefficient of a target tight sandstone reservoir;

[0231] determining a volume modulus of an initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral;

[0232] establishing micro-pores in the initial rock matrix according to the connected porosity and the unconnected porosity to obtain a modified rock matrix corresponding to the target tight sandstone reservoir, and determining a volume modulus of the modified rock matrix and a shear modulus of the modified rock matrix based on the volume modulus of the initial rock matrix;

[0233] determining a rock skeleton volume modulus according to the volume modulus of the modified rock matrix and the densification degree coefficient, and determining a rock skeleton shear modulus according to the shear modulus of the modified rock matrix and the densification degree coefficient;

[0234] filling a gas-water mixed fluid in the micro-pores of the rock skeleton according to the water saturation to obtain a saturated rock corresponding to the target tight sandstone reservoir, and determining a volume modulus of the gas-water mixed fluid;

[0235] determining a volume modulus of the saturated rock according to the connected porosity, the volume modulus of the modified rock matrix, the volume modulus of the dry rock, and the volume modulus of the gas-water mixed fluid, and determining a shear modulus of the saturated rock according to the rock skeleton shear modulus.

[0236] Further, the computer program, when executed by the processor, can further implement the following steps:

[0237] determining a P-wave velocity and an S-wave velocity in the saturated rock corresponding to the target tight sandstone reservoir according to the volume modulus of the saturated rock, the shear modulus of the saturated rock, and a density of the saturated rock obtained in advance.

[0238] Further, the computer program, when executed by the processor, can further implement the following steps:

[0239] determining an initial P-wave velocity, an initial S-wave velocity, and an initial density of the initial rock matrix based on the volume modulus of the initial rock matrix;

[0240] determining a modified P-wave velocity of the modified rock matrix according to the initial P-wave velocity, the unconnected porosity, and a P-wave velocity of a fluid in the unconnected pores obtained in advance, and determining a modified S-wave velocity of the modified rock matrix according to the initial S-wave velocity, the unconnected porosity, the initial density, and a density of the fluid obtained in advance.

[0241] determining a compressive modulus of the modified rock matrix and a shear modulus of the modified rock matrix according to the modified longitudinal wave velocity, the modified transverse wave velocity, the unconnected porosity, the density of the fluid, and the initial density;

[0242] generating a bulk modulus of the modified rock matrix according to the compressive modulus of the modified rock matrix.

[0243] Further, the computer program, when executed by the processor, can further implement the following steps:

[0244] determining a rock skeleton bulk modulus according to a preset rock skeleton bulk modulus calculation formula;

[0245] The rock skeleton bulk modulus calculation formula is:

[0246]

[0247] wherein, K dry represents the rock skeleton bulk modulus, K ma represents the bulk modulus of the modified rock matrix, represents the connected porosity, and Z represents the densification degree coefficient.

[0248] Further, the computer program, when executed by the processor, can further implement the following steps:

[0249] determining a saturated rock bulk modulus according to a preset saturated rock bulk modulus calculation formula;

[0250] The saturated rock bulk modulus calculation formula is:

[0251]

[0252] wherein, K sat represents the saturated rock bulk modulus, K f represents the bulk modulus of the gas-water mixed fluid, represents the connected porosity.

[0253] Further, the computer program, when executed by the processor, can further implement the following steps:

[0254] determining a rock skeleton shear modulus according to a preset rock skeleton shear modulus calculation formula;

[0255] The rock skeleton shear modulus calculation formula is:

[0256]

[0257] wherein, U drydenotes the shear modulus of the rock skeleton, U ma denotes the shear modulus of the modified rock matrix, denotes the connected porosity, Z denotes the degree of compaction coefficient.

[0258] Further, in the above embodiment, the computer program can further implement the following steps when executed by the processor:

[0259] According to a preset shear modulus calculation formula of the saturated rock, the shear modulus of the saturated rock is determined.

[0260] The shear modulus calculation formula of the saturated rock is:

[0261] U sat = U dry

[0262] wherein, U sat denotes the shear modulus of the saturated rock.

[0263] Further, in the above embodiment, the computer program can further implement the following steps when executed by the processor:

[0264] According to the water saturation, a proportion coefficient between gas and water is determined.

[0265] According to the proportion coefficient between gas and water, a gas-water mixed fluid is filled in the micro-pore of the dry rock to obtain a saturated rock corresponding to the target compacted sandstone reservoir.

[0266] According to a preset bulk modulus calculation formula of the gas-water mixed fluid, the bulk modulus of the gas-water mixed fluid is determined.

[0267] The bulk modulus calculation formula of the gas-water mixed fluid is:

[0268]

[0269] wherein, S Hc denotes the gas saturation in the connected pore, denotes the total connected porosity, denotes the connected porosity, denotes the unconnected porosity, S wc denotes the water saturation in the connected pore, K f denotes the bulk modulus of the gas-water mixed fluid.

[0270] It can be understood that the same or similar parts in the above embodiments can be mutually referred to, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0271] It should be noted that, in the description of the present application, the terms "first", "second" and the like are used only for descriptive purposes, and cannot be construed as indicating or implying relative importance. In addition, in the description of the present application, the meaning of "a plurality of" is at least two, unless otherwise specified.

[0272] Any process or method descriptions or descriptions of the flow diagrams described herein or otherwise described in the present application can be understood as representing the steps of the codes implemented as code means of a computer program or code modules of the programs, and the scope of the preferred embodiments of the present application includes additional implementation, in which the functions according to the features involved can be performed in an order different from that shown or discussed, including in a substantially simultaneous manner or in reverse order, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0273] It should be understood that parts of the present application can be realized by hardware, software, firmware or their combination. In the above embodiments, a plurality of steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if realized by hardware, and as in another embodiment, it can be realized by any one or their combination of the following technologies known in the art: discrete logic circuit with logic gate circuit for implementing logic function on data signal, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) and the like.

[0274] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by program instructions to the relevant hardware, and the program can be stored in a computer readable storage medium, which includes one or a combination of steps of the method embodiments when executed.

[0275] In addition, each functional unit in each embodiment of the present application can be integrated in a processing module 32, or each unit can be physically present separately, or two or more units can be integrated in a module. The above integrated module can be realized in the form of hardware or in the form of software functional module. The integrated module, if realized in the form of software functional module and sold or used as an independent product, can also be stored in a computer readable storage medium.

[0276] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0277] In the description of the specification, reference to "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" in

[0278] Although the disclosed embodiments of the present application are as described above, the content described is only the embodiments adopted for facilitating the understanding of the present application, and is not intended to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form of implementation and details without departing from the spirit and scope of the present application, but the protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A method of determining the elastic modulus of a tight sand reservoir, characterized in that, The method comprises: obtaining connected porosity, unconnected porosity, water saturation, target mineral, volume content of the target mineral and a densification degree coefficient of a target tight sandstone reservoir; determining a volume modulus of an initial rock matrix corresponding to the target tight sandstone reservoir according to the target mineral and the volume content of the target mineral; establishing micro-pores in the initial rock matrix according to the connected porosity and the unconnected porosity to obtain a modified rock matrix corresponding to the target tight sandstone reservoir, and determining a volume modulus of the modified rock matrix and a shear modulus of the modified rock matrix based on the volume modulus of the initial rock matrix; determining a rock skeleton volume modulus according to the volume modulus of the modified rock matrix and the densification degree coefficient, and determining a rock skeleton shear modulus according to the shear modulus of the modified rock matrix and the densification degree coefficient; filling a gas-water mixed fluid in the micro-pores of the rock skeleton according to the water saturation to obtain a saturated rock corresponding to the target tight sandstone reservoir, and determining a volume modulus of the gas-water mixed fluid; determining a volume modulus of the saturated rock according to the connected porosity, the volume modulus of the modified rock matrix, a volume modulus of dry rock, the volume modulus of the gas-water mixed fluid, and determining a shear modulus of the saturated rock according to the rock skeleton shear modulus; wherein the densification degree coefficient is determined according to at least a consolidation feature and a shape of pores; wherein the densification degree coefficient is optimized based on a simulated annealing method and the unconnected porosity; wherein filling the gas-water mixed fluid in the micro-pores of the rock skeleton according to the water saturation to obtain the saturated rock corresponding to the target tight sandstone reservoir and determining the volume modulus of the gas-water mixed fluid comprises: determining a proportion coefficient between gas and water according to the water saturation; filling the gas-water mixed fluid in the micro-pores of the dry rock according to the proportion coefficient between gas and water to obtain the saturated rock corresponding to the target tight sandstone reservoir; determining the volume modulus of the gas-water mixed fluid according to a preset volume modulus calculation formula of the gas-water mixed fluid; the volume modulus calculation formula of the gas-water mixed fluid is: wherein, Sgc represents the gas saturation in the connected porosity, Sgt represents the total connected porosity, Sgc represents the connected porosity, Sunc represents the unconnected porosity, Swc represents the water saturation in the connected porosity, K represents the bulk modulus of the gas-water mixture.

2. The method of determining the elastic modulus of a tight sand reservoir of claim 1, wherein, The method further comprises: determining a P-wave velocity and an S-wave velocity in the saturated rock corresponding to the target tight sandstone reservoir according to the volume modulus of the saturated rock, the shear modulus of the saturated rock and a pre-obtained density of the saturated rock.

3. The method of determining the elastic modulus of a tight sand reservoir of claim 1, wherein, The method further comprises: determining an initial P-wave velocity, an initial S-wave velocity and an initial density of the initial rock matrix based on the volume modulus of the initial rock matrix. determining a corrected P-wave velocity of the corrected rock matrix according to the initial P-wave velocity, the unconnected porosity and a P-wave velocity of a fluid in the unconnected porosity obtained in advance, and determining a corrected S-wave velocity of the corrected rock matrix according to the initial S-wave velocity, the unconnected porosity, the initial density and a density of the fluid obtained in advance; determining a compression modulus of the corrected rock matrix and a shear modulus of the corrected rock matrix according to the corrected P-wave velocity, the corrected S-wave velocity, the unconnected porosity, the density of the fluid and the initial density; generating a bulk modulus of the corrected rock matrix according to the compression modulus of the corrected rock matrix.

4. The method of determining the elastic modulus of a tight sand reservoir according to claim 3, wherein, The method for determining the rock skeleton bulk modulus comprises: determining the rock skeleton bulk modulus according to a preset rock skeleton bulk modulus calculation formula; the rock skeleton bulk modulus calculation formula is: wherein, represents the bulk modulus of the rock matrix, represents the bulk modulus of the modified rock matrix, represents the connected porosity, represents the degree of compaction coefficient.

5. The method of determining the elastic modulus of a tight sand reservoir according to claim 4, wherein, The method for determining the bulk modulus of the saturated rock comprises: determining the bulk modulus of the saturated rock according to a preset bulk modulus calculation formula of the saturated rock; the bulk modulus calculation formula of the saturated rock is: wherein, Ks represents the bulk modulus of the saturated rock, Kf represents the bulk modulus of the gas-water mixture fluid, φc represents the connected porosity.

6. The method of determining the elastic modulus of a tight sand reservoir of claim 3, wherein, The method for determining the rock skeleton shear modulus comprises: determining the rock skeleton shear modulus according to a preset rock skeleton shear modulus calculation formula; the rock skeleton shear modulus calculation formula is: wherein, G represents the shear modulus of the rock matrix, G represents the shear modulus of the modified rock matrix, G represents the connected porosity, G represents the degree of compaction coefficient.

7. The method of determining the elastic modulus of a tight sand reservoir according to claim 6, wherein, The method for determining the shear modulus of the saturated rock comprises: determining the shear modulus of the saturated rock according to a preset shear modulus calculation formula of the saturated rock; the shear modulus calculation formula of the saturated rock is: wherein, G represents the shear modulus of the saturated rock.

8. An apparatus for detecting the elastic modulus of a tight sandstone reservoir, characterized in that, comprise a memory and a processor; The memory has stored thereon a computer program, and the computer program is executed by the processor to implement the steps of the method for determining the elastic modulus of the tight sandstone reservoir according to any one of claims 1 to 7.

9. A storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to implement the steps of the method for determining the elastic modulus of the tight sandstone reservoir according to any one of claims 1 to 7.

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