Conventional logging-based tight sandstone geology-engineering integrated sweet spot evaluation method

Abstract

This application discloses an integrated geological and engineering sweet spot evaluation method, device, equipment, and storage medium for tight sandstone based on conventional logging. The method includes: acquiring logging curve data and experimental analysis data of already mined sandstone and mudstone; calculating the comprehensive characterization factor of each logging segment and the fracture porosity of the sandstone and mudstone reservoir to determine their lower limits; determining the gas saturation of each logging segment based on the Simon formula; acquiring the actual permeability of multiple logging segments and performing correlation analysis to determine the lower limit of the actual permeability of multiple segments; for any well to be evaluated, determining the geological sweet spot in the well to be evaluated based on the comprehensive characterization factor, fracture porosity, gas saturation, and the lower limit of the actual permeability; determining the engineering sweet spot of the well to be evaluated based on the compressibility index of the logging; and determining the effective reservoir segment of the sandstone and mudstone of any well to be evaluated based on the engineering sweet spot and the geological sweet spot.

Description

Technical Field

[0001] This application belongs to the field of oilfield development technology, and in particular relates to a method, apparatus, equipment and storage medium for evaluating sweet spots in tight sandstone geological engineering based on conventional logging. Background Technology

[0002] With the exploration and development of oil and gas, more and more unconventional resources such as tight sandstone gas have been discovered, demonstrating the promising exploration and development prospects of tight sandstone reservoirs. The sedimentary type, scale, and lithofacies distribution of tight sandstone are controlled by a combination of factors such as paleotectonic activity, lacustrine (sea) level rise and fall, and paleoclimate conditions. It is a dominant reservoir rock type and has become a research hotspot both inside and outside the industry in recent years. The sedimentary process and tectonic setting in which it forms determine the special characteristics of sandstone oil and gas reservoirs.

[0003] Currently, scholars at home and abroad have conducted a lot of research on the identification of tight sandstone gas reservoirs. However, most of them judge the effective reservoirs based on the lower limit of the "four properties" of reservoir lithology, physical properties, electrical properties and oil content. This method has the following drawbacks: insufficient basis for identifying effective reservoirs, insufficient accuracy, lack of identification and understanding of fractures, and the reference basis for favorable reservoirs is limited to geological sweet spots, lacking the judgment of compressibility, i.e., engineering sweet spots. The method has certain defects. Summary of the Invention

[0004] The embodiments of this application provide a method, apparatus, equipment and storage medium for evaluating sweet spots in tight sandstone geological engineering based on conventional well logging, thereby enabling rapid identification of high-quality reservoirs.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to a first aspect of the embodiments of this application, a method for evaluating sweet spots in tight sandstone geological engineering based on conventional well logging is provided, comprising:

[0007] Obtain well logging data and experimental analysis data of the already mined sandstone and mudstone.

[0008] Based on the well logging curve data and the experimental analysis and testing data, the comprehensive characterization factor of each segment of the well logging and the fracture porosity of the sandstone and mudstone reservoir are calculated to determine the lower limit values ​​of the comprehensive characterization factor and the fracture porosity. The comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the porosity-permeability relationship.

[0009] The gas saturation of each segment of the well logging is determined based on the Simon formula;

[0010] The actual permeability of multiple segments in the well logging is obtained, and a correlation analysis is performed based on the actual permeability to determine the lower limit value of the actual permeability of the multiple segments.

[0011] For any oil well to be evaluated, the geological sweet spot in the oil well to be evaluated is determined based on the comprehensive characterization factor, the fracture porosity, the gas saturation, and the lower limit of the actual permeability.

[0012] The engineering sweet spot of the oil well to be evaluated is determined based on the compressibility index of the well log.

[0013] Based on the engineering sweet spot and the geological sweet spot, the effective reservoir section of sandstone and mudstone in any well to be evaluated is determined.

[0014] In some embodiments of this application, based on the foregoing scheme, determining the geological sweet spot in any well to be evaluated according to the lower limit of the comprehensive characterization factor, the fracture porosity, the gas saturation, and the actual permeability includes: for any well to be evaluated, calculating the comprehensive characterization factor, the fracture porosity, the gas saturation, and the actual permeability of each segment of the well; for any segment of any well to be evaluated, if the comprehensive characterization factor, the fracture porosity, the gas saturation, and the actual permeability of the segment are all greater than the lower limit determined based on the already exploited sandstone and mudstone, then the segment is determined as the geological sweet spot in the well to be evaluated.

[0015] In some embodiments of this application, based on the foregoing scheme, determining the engineering sweet spot of the well to be evaluated based on the compressibility index of the well logging includes: calculating the compressibility index of multiple segments of the already mined sandstone and mudstone, and the compressibility index of multiple segments of the well to be evaluated; determining a lower limit value for the compressibility index based on the compressibility index of the multiple segments of the already mined sandstone and mudstone; and for any segment of any well to be evaluated, if the compressibility index of the segment is greater than the lower limit value for the compressibility index, determining the segment as the engineering sweet spot of the well to be evaluated.

[0016] In some embodiments of this application, based on the aforementioned scheme, the comprehensive characterization factor RC of each segment is calculated according to formula (1):

[0017] RC=SP*1-R|*φ (1)

[0018] Where Φ is the porosity of the sandstone and mudstone reservoir that has been mined, which is a percentage; SP is the sorting coefficient of the pore throat; and R is the average pore radius of the rock, in μm.

[0019] In some embodiments of this application, based on the foregoing scheme, the crack porosity of each segment is calculated according to formula (2):

[0020]

[0021] Among them, R mf R represents the resistivity of the mud filtrate, expressed in Ω·m. LLS Shallow lateral, unit is Ω.m, R LLD For deep lateral direction, the unit is Ω·m, φ 裂缝 The value represents the crack porosity, in percentages (m). f This represents the crack porosity index.

[0022] In some embodiments of this application, based on the foregoing scheme, the gas saturation of each segment is calculated according to formula (3):

[0023]

[0024] Where n is the saturation index, S w The water saturation level is expressed as a percentage. R represents the clay content as a percentage. sh The resistivity is the amount of clay content, expressed in Ω·m, φ. c R represents the inorganic porosity as a percentage, α is the lithology coefficient, and R is the inorganic porosity. w R represents the resistivity of formation water, expressed in Ω·m. t The value represents the formation resistivity, expressed in Ω·m.

[0025] In some embodiments of this application, based on the foregoing scheme, the compressibility index Y of each segment is calculated according to formula (4). 可压性 :

[0026] Y 可压性 =0.21*Vp+3.51*Vs-1.68*YM+2.65*PR (4)

[0027] Among them, V p The longitudinal wave time difference is expressed in μs / ft, V. s , where is the transverse wave time difference in μs / ft, YM is Young's modulus in MPa, and PR is Poisson's ratio in MPa.

[0028] According to a second aspect of the embodiments of this application, an integrated sweet spot evaluation device for tight sandstone geological engineering based on conventional well logging is provided, comprising:

[0029] The experimental data acquisition module is used to acquire well logging curve data and experimental analysis and testing data of the already mined sandstone and mudstone.

[0030] The data calculation module is used to calculate the comprehensive characterization factor of each segment of the well logging and the fracture porosity of the sandstone and mudstone reservoir based on the well logging curve data and the experimental analysis and testing data, so as to determine the lower limit values ​​of the comprehensive characterization factor and the fracture porosity respectively. The comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the pore-permeability relationship. The module determines the gas saturation of each segment of the well logging based on the Simon formula. The module obtains the actual permeability of multiple segments of the well logging and performs correlation analysis based on the actual permeability to determine the lower limit value of the actual permeability of the multiple segments.

[0031] The geological sweet spot determination module is used to determine the geological sweet spot in any oil well to be evaluated based on the comprehensive characterization factor, the fracture porosity, the gas saturation, and the lower limit of the actual permeability.

[0032] The engineering sweet spot determination module is used to determine the engineering sweet spot of the well to be evaluated based on the compressibility index of the well log.

[0033] The effective reservoir section determination module is used to determine the effective reservoir section of sandstone and mudstone in any well to be evaluated based on the engineering sweet spot and the geological sweet spot.

[0034] According to a third aspect of the embodiments of this application, an integrated sweet spot evaluation device for tight sandstone geological engineering based on conventional well logging is provided, including a processor and a memory. The memory stores computer program instructions that can be executed by the processor. When the processor executes the computer program instructions, it implements the steps of the method described in any of the first aspects above.

[0035] According to a fourth aspect of the embodiments of this application, a computer-readable storage medium is provided, wherein computer program instructions are stored therein, and when executed by a processor, the computer program instructions cause the processor to perform the steps of the method as described in any of the first aspects above.

[0036] This proposal presents a method for evaluating the integrated geological and engineering sweet spots in tight sandstone based on conventional well logging. It extracts sensitive parameters of reservoir fluid properties, establishes refined evaluation criteria for both geological and engineering sweet spots, and forms a quantitative identification technique for favorable reservoirs. This provides a foundation for the effective utilization of this type of gas reservoir. The effective reservoir identification method provided by this proposal is accurate, fast, and easy to promote.

[0037] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0039] Figure 1 A flowchart illustrating an integrated sweet spot evaluation method for tight sandstone geology and engineering based on conventional well logging is shown in one embodiment.

[0040] Figure 2 A flowchart illustrating an integrated geological and engineering sweet spot evaluation method for tight sandstone based on conventional well logging is shown in another embodiment.

[0041] Figure 3 A block diagram of an integrated sweet spot evaluation device for tight sandstone geology and engineering based on conventional well logging is shown in one embodiment;

[0042] Figure 4 A schematic diagram of an integrated sweet spot evaluation device for tight sandstone geology and engineering based on conventional well logging is shown in one embodiment. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0045] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0046] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0047] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0048] Figure 1 A flowchart illustrating an integrated sweet spot evaluation method for tight sandstone geology and engineering based on conventional well logging is shown in one embodiment. Figure 1 As shown, a method for evaluating sweet spots in tight sandstone geological engineering based on conventional well logging is provided. This method may include the following steps:

[0049] Step 101: Obtain well logging curve data and experimental analysis data of the mined sandstone and mudstone.

[0050] Step 102: Calculate the comprehensive characterization factor of each segment of the well logging and the fracture porosity of the sandstone and mudstone reservoir based on the logging curve data and experimental analysis data, so as to determine the lower limit values ​​of the comprehensive characterization factor and fracture porosity respectively.

[0051] Step 103: Determine the gas saturation of each segment of the well logging based on the Simon formula.

[0052] Step 104: Obtain the actual permeability of multiple segments in the well logging, and perform correlation analysis based on the actual permeability to determine the lower limit of the actual permeability of multiple segments.

[0053] Step 105: For any oil well to be evaluated, determine the geological sweet spot in the oil well to be evaluated based on the comprehensive characterization factors, fracture porosity, gas saturation and the lower limit of actual permeability.

[0054] Step 106: Determine the engineering sweet spot of the oil well to be evaluated based on the compressibility index of the well log.

[0055] Step 107: Determine the effective reservoir section of sandstone and mudstone for any well to be evaluated based on the engineering sweet spot and the geological sweet spot.

[0056] In this scheme, for already exploited oil wells, logging data and experimental analysis data of the sandstone and mudstone can be obtained. The logging data includes spontaneous potential (SP), natural gamma ray (GR), acoustic transit time (AC), resistivity (RD), density (DEN), and neutron density (CNL). The experimental analysis data includes mercury intrusion porosimetry (MIP) data, measured porosity data, measured saturation data, permeability data, and whole-rock diffraction data. The MIP data includes the average capillary radius and the sorting coefficient of the pore throat. The whole-rock diffraction data can be used to predict the content of brittle minerals. Then, the porosity, average capillary radius, and sorting coefficient of the pore throat in the sandstone and mudstone of the already exploited oil wells can be used to quantitatively characterize the micropore structure of the reservoir rock. The pore throat radius is used to evaluate micropores, and the sorting coefficient of the pore throat reflects the degree of distribution and concentration of the pore throats. The smaller the sorting coefficient, the better the pore sorting and the more uniform the distribution. There are many criteria for stratification. Here, we are dividing into smaller segments. The He8 segment and the Shan1 segment were first divided into a large segment according to the stratigraphic age, and then divided into two smaller segments according to the changes in sedimentary environment and lithofacies characteristics. Here, the He8 segment and the Shan1 segment are two segments with completely different development environments and lithofacies types, which can be used as a basis for drawing strata.

[0057] like Figure 2 As shown, the comprehensive characterization factor and fracture porosity of each segment of the well logging can be calculated based on well logging curve data and experimental analysis data, so as to determine the lower limit values ​​of the comprehensive characterization factor and fracture porosity respectively. Among them, the comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the porosity-permeability relationship.

[0058] In one embodiment, the comprehensive characterization factor RC for each segment can be calculated according to formula (1):

[0059] RC=SP*1-R|*φ (1)

[0060] Where Φ represents the porosity of the already mined sandstone and mudstone reservoir, as a percentage; SP represents the sorting coefficient of the pore throat; and R represents the average pore radius of the rock, in μm. The reservoir's micropore structure is characterized by a comprehensive pore structure characterization factor. A larger RC (comprehensive characterization factor) indicates a larger pore throat, more regular pore shape, and a better porosity-permeability relationship.

[0061] In one embodiment, the crack porosity of each segment can be calculated according to formula (2):

[0062]

[0063] Among them, R mf R represents the resistivity of the mud filtrate, expressed in Ω·m.LLS Shallow lateral, unit is Ω.m, R LLD For deep lateral direction, the unit is Ω·m, φ 裂缝 The value represents the crack porosity, in percentages (m). f The formula is an improvement on the Archie formula. This scheme uses a fracture cube model, which is an idealized model. The rock is cut into uniformly sized cubes, with its volume as the unit 1. The side length of the matrix rock block is converted to a decimal x, and then the formula (2) is used to calculate the fracture porosity of each segment.

[0064] As can be seen, any given oil well can be divided into multiple segments. Based on logging data and experimental analysis, the comprehensive characterization factor and fracture porosity of the sandstone and mudstone reservoir for each segment are calculated. After calculating the comprehensive characterization factor and fracture porosity of each segment, the minimum value among these multiple comprehensive characterization factors and fracture porosity can be determined. Therefore, the lower limit values ​​for the comprehensive characterization factor and fracture porosity of the sandstone and mudstone reservoir for other oil wells to be evaluated can also be determined.

[0065] Furthermore, the gas saturation of each segment of the well logging can be determined based on the Simon formula. Typically, the Archie formula can be used to calculate the gas saturation. However, the Archie formula does not consider the influence of clay content on conductivity, because clay has a large specific surface area, inherent surface negative charge, can adsorb a small amount of water, and has the ability to form an electric dipole layer. Therefore, the skeleton of argillaceous sandstone has a certain conductivity. At the same time, the Archie formula does not consider the influence of reservoir heterogeneity and requires that the spatial distribution of rock porosity be uniform to ensure that the electrical properties of the rock are isotropic. Thus, the Archie formula has certain defects and inapplicability. Under complex geological conditions, the nature of rocks is heterogeneous and anisotropic. Therefore, the Simon formula is used to calculate the saturation of the study area. The Simon formula can, to a certain extent, eliminate the influence of the unique conductivity of clay on formation resistivity through clay correction. In one embodiment, the gas saturation of each segment can be calculated according to formula (3):

[0066]

[0067] Where n is the saturation index, S w The water saturation level is expressed as a percentage. R represents the clay content as a percentage. sh The resistivity is the amount of clay content, expressed in Ω·m, φ. c R represents the inorganic porosity as a percentage, α is the lithology coefficient, and R is the inorganic porosity. w R represents the resistivity of formation water, expressed in Ω·m. tThe value represents the formation resistivity, expressed in Ω·m.

[0068] Furthermore, the actual permeability of multiple segments in the well logging can be obtained, and correlation analysis can be performed based on the actual permeability to determine the lower limit value of the actual permeability of multiple segments. Specifically, a permeability sensitive curve can be selected, that is, correlation analysis can be performed on the curves of spontaneous potential (SP), natural gamma ray (GR), sonic transit time (AC), density (DEN), and resistivity (RD) with the measured porosity data, and the curve with the highest correlation can be selected as the sensitive curve, and then correlation analysis of measured permeability can be performed. In the study area, the sandstone and mudstone well reservoir segments are long, and the reservoir properties vary greatly throughout the well segment, exhibiting strong heterogeneity. Therefore, it is necessary to perform multivariate regression fitting of permeability segment by segment. The formula is as follows:

[0069] Permeability = -0.046*GR + 0.029*SP + 0.0775*POR + 0.034*CNL - + 0.545*DEN

[0070] Where POR stands for porosity and CNL stands for neutron logging.

[0071] This method allows for the determination of the lower limit of actual permeability across multiple logging segments. Thus, data from sandstone and mudstone in already-exploited oil wells has established the lower limits for comprehensive characterization factors, fracture porosity, gas saturation, and actual permeability. Then, for any given oil well to be evaluated, the geological sweet spot within that well can be determined based on these comprehensive characterization factors, fracture porosity, gas saturation, and the lower limit of actual permeability.

[0072] In one embodiment, determining the geological sweet spot in any well to be evaluated based on the lower limit values ​​of the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability includes: for any well to be evaluated, calculating the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of each segment of the well; for any segment of any well to be evaluated, if the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of the segment are all greater than the lower limit values ​​determined based on the already exploited sandstone and mudstone, the segment is determined as a geological sweet spot in the well to be evaluated.

[0073] Current national standards for unconventional oil and gas generally define geological sweet spots based on four properties: lithology, reservoir properties, oil-bearing capacity, and compressibility. However, the national standard assigns compressibility to engineering sweet spots. Since the study area contains tight sandstone gas, which falls under the category of conventional oil and gas, when selecting geological sweet spots based on the four properties, lithology is broadly classified into sandstone and mudstone. The favorable lithology here is sandstone, which is the dominant type; mudstone is not considered. When evaluating reservoirs, only sandstone can be considered. Therefore, when selecting geological sweet spots, lithology can be disregarded; only reservoir properties and oil-bearing capacity need to be considered. Reservoir properties refer to porosity, while oil-bearing capacity refers to permeability, gas saturation, and fracture porosity. These are the criteria used in this scheme for selecting geological sweet spots.

[0074] Specifically, regardless of whether it's a well to be evaluated or an already exploited well, the formulas mentioned in the above embodiments can be used to calculate the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of each segment of the well. Then, the lower limits of the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability can be determined based on the exploited sandstone and mudstone reservoir. Therefore, for any segment of any well to be evaluated, if the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of the segment are all greater than the lower limits determined based on the exploited sandstone and mudstone reservoir, the segment is identified as a geological sweet spot in the well to be evaluated. Therefore, a geological sweet spot in any well to be evaluated can be determined in this way.

[0075] Furthermore, the engineering sweet spot of the oil well to be evaluated can be determined based on the compressibility index of the well log.

[0076] In one embodiment, determining the engineering sweet spot of the well to be evaluated based on the compressibility index of the well logging includes: calculating the compressibility index of multiple segments of the already mined sandstone and mudstone, and the compressibility index of multiple segments of the well to be evaluated; determining a lower limit value for the compressibility index based on the compressibility index of the multiple segments of the already mined sandstone and mudstone; and for any segment of any well to be evaluated, if the compressibility index of the segment is greater than the lower limit value for the compressibility index, the segment is determined as the engineering sweet spot of the well to be evaluated.

[0077] Similarly, the compressibility index of multiple segments of sandstone and mudstone in an already exploited oil well can be calculated, and the minimum value among these compressibility indices, i.e., the lower limit of the compressibility index, can be determined. The compressibility index of multiple segments in an oil well to be evaluated can be calculated in the same way. For any segment of any oil well to be evaluated, if the compressibility index of that segment is greater than the lower limit of the compressibility index, that segment can be identified as an engineering sweet spot for the oil well to be evaluated.

[0078] In one embodiment, the compressibility index Y of each segment can be calculated according to formula (4). 可压性 :

[0079] Y 可压性 =0.21*Vp+3.51*Vs-1.68*YM+2.65*PR (4)

[0080] Among them, V p The longitudinal wave time difference is expressed in μs / ft, V. s , where is the transverse wave time difference in μs / ft, YM is Young's modulus in MPa, and PR is Poisson's ratio in MPa.

[0081] Then, based on the engineering sweet spot and geological sweet spot, the effective reservoir section of sandstone and mudstone for any well to be evaluated can be determined. That is, for any well to be evaluated, if the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of any segment are all greater than the lower limit values ​​determined based on the already exploited sandstone and mudstone, and the compressibility index of that segment is also greater than the lower limit value of the compressibility index determined based on the already exploited sandstone and mudstone, then that segment can be determined as the effective reservoir section of sandstone and mudstone for the well to be evaluated.

[0082] This proposal presents a method for evaluating the integrated geological and engineering sweet spots in tight sandstone based on conventional well logging. It extracts sensitive parameters of reservoir fluid properties, establishes refined evaluation criteria for both geological and engineering sweet spots, and forms a quantitative identification technique for favorable reservoirs. This provides a foundation for the effective utilization of this type of gas reservoir. The effective reservoir identification method provided by this proposal is accurate, fast, and easy to promote.

[0083] The following describes an embodiment of the apparatus described in this application, which can be used to execute the integrated sweet spot evaluation method for tight sandstone geology and engineering based on conventional well logging described in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the integrated sweet spot evaluation method for tight sandstone geology and engineering based on conventional well logging described in the above applications.

[0084] Figure 3 A block diagram of an integrated sweet spot evaluation device for tight sandstone geology and engineering based on conventional well logging, as described in an embodiment of this application, is shown. Figure 3As shown in the embodiment of this application, the integrated sweet spot evaluation device for tight sandstone geology and engineering based on conventional logging includes: an experimental data acquisition module 301, used to acquire logging curve data and experimental analysis and testing data of the already mined sandstone and mudstone; and a data calculation module 302, used to calculate the comprehensive characterization factor of each segment of the logging and the fracture porosity of the sandstone and mudstone reservoir based on the logging curve data and experimental analysis and testing data, so as to determine the lower limit values ​​of the comprehensive characterization factor and the fracture porosity, wherein the comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the porosity-permeability relationship; based on the Western... The gate formula determines the gas saturation of each segment of the well logging; the actual permeability of multiple segments of the well logging is obtained, and correlation analysis is performed based on the actual permeability to determine the lower limit value of the actual permeability of multiple segments; the geological sweet spot determination module 303 is used to determine the geological sweet spot in any well to be evaluated based on the comprehensive characterization factor, fracture porosity, gas saturation, and the lower limit value of actual permeability; the engineering sweet spot determination module 304 is used to determine the engineering sweet spot of the well to be evaluated based on the compressibility index of the well logging; the effective reservoir section determination module 305 is used to determine the effective reservoir section of sandstone and mudstone in any well to be evaluated based on the engineering sweet spot and the geological sweet spot.

[0085] In some embodiments of this application, based on the aforementioned scheme, the geological sweet spot determination module 303 is further configured to calculate, for any one oil well to be evaluated, the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of each segment of the oil well to be evaluated; and for any segment of any one oil well to be evaluated, if the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of the segment are all greater than the lower limit determined based on the already exploited sand and mudstone, the segment is determined as a geological sweet spot in the oil well to be evaluated.

[0086] In some embodiments of this application, based on the foregoing scheme, the engineering sweet spot determination module 304 is further configured to calculate the compressibility index of multiple segments of the already mined sandstone and mudstone, and the compressibility index of multiple segments of the well to be evaluated; determine a lower limit value for the compressibility index based on the compressibility index of the multiple segments of the already mined sandstone and mudstone; and for any segment of any well to be evaluated, if the compressibility index of the segment is greater than the lower limit value for the compressibility index, determine the segment as the engineering sweet spot of the well to be evaluated.

[0087] In some embodiments of this application, based on the aforementioned scheme, the comprehensive characterization factor RC of each segment is calculated according to formula (1):

[0088] RC=SP*1-R|*φ (1)

[0089] Where Φ is the porosity of the sandstone and mudstone reservoir that has been mined, which is a percentage; SP is the sorting coefficient of the pore throat; and R is the average pore radius of the rock, in μm.

[0090] In some embodiments of this application, based on the foregoing scheme, the crack porosity of each segment is calculated according to formula (2):

[0091]

[0092] Among them, R mf R represents the resistivity of the mud filtrate, expressed in Ω·m. LLS Shallow lateral, unit is Ω.m, R LLD For deep lateral direction, the unit is Ω·m, φ 裂缝 The value represents the crack porosity, in percentages (m). f This represents the crack porosity index.

[0093] In some embodiments of this application, based on the foregoing scheme, the gas saturation of each segment is calculated according to formula (3):

[0094]

[0095] Where n is the saturation index, S w The water saturation level is expressed as a percentage. R represents the clay content as a percentage. sh The resistivity is the amount of clay content, expressed in Ω·m, φ. c R represents the inorganic porosity as a percentage, α is the lithology coefficient, and R is the inorganic porosity. w R represents the resistivity of formation water, expressed in Ω·m. t The value represents the formation resistivity, expressed in Ω·m.

[0096] In some embodiments of this application, based on the foregoing scheme, the compressibility index Y of each segment is calculated according to formula (4). 可压性 :

[0097] Y 可压性 =0.21*Vp+3.51*Vs-1.68*YM+2.65*PR (4)

[0098] Among them, V p The longitudinal wave time difference is expressed in μs / ft, V. s , where is the transverse wave time difference in μs / ft, YM is Young's modulus in MPa, and PR is Poisson's ratio in MPa.

[0099] Based on the same inventive concept, this application also provides an integrated sweet spot evaluation device for tight sandstone geological engineering based on conventional well logging, see reference. Figure 4The diagram shows a schematic of the structure of an integrated sweet spot evaluation device for tight sandstone geological engineering based on conventional logging in an embodiment of this application. The evaluation device for the sensitivity of shale porosity to the acidity and alkalinity of the influent includes one or more memories 504, one or more processors 502, and at least one computer program (computer program instruction) stored in the memory 504 and executable on the processor 502. When the processor 502 executes the computer program, it implements the method described above.

[0100] Among them, Figure 4 In this document, a bus architecture (represented by bus 500) is used. Bus 500 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 502 and memory represented by memory 504. Bus 500 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 505 provides an interface between bus 500 and receiver 501 and transmitter 503. Receiver 501 and transmitter 503 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 502 is responsible for managing bus 500 and general processing, while memory 504 can be used to store data used by processor 502 during operation.

[0101] Based on the same inventive concept, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, cause the processor to perform the steps of the method described above.

[0102] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit.

[0103] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0104] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0105] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, 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 computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing computer program instructions, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0106] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for evaluating sweet spots in tight sandstone geological engineering based on conventional well logging, characterized in that, The method includes: Obtain well logging data and experimental analysis data of the already mined sandstone and mudstone. Based on the well logging curve data and the experimental analysis and testing data, the comprehensive characterization factor of each segment of the well logging and the fracture porosity of the sandstone and mudstone reservoir are calculated to determine the lower limit values ​​of the comprehensive characterization factor and the fracture porosity. The comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the porosity-permeability relationship. The gas saturation of each segment of the well logging is determined based on the Simon formula; The actual permeability of multiple segments in the well logging is obtained, and a correlation analysis is performed based on the actual permeability to determine the lower limit value of the actual permeability of the multiple segments. For any oil well to be evaluated, the geological sweet spot in the oil well to be evaluated is determined based on the comprehensive characterization factor, the fracture porosity, the gas saturation, and the lower limit of the actual permeability. The engineering sweet spot of the oil well to be evaluated is determined based on the compressibility index of the well log. Based on the engineering sweet spot and the geological sweet spot, the effective reservoir section of sandstone and mudstone in any well to be evaluated is determined.

2. The method according to claim 1, characterized in that, For any given oil well to be evaluated, the geological sweet spots in the oil well to be evaluated are determined based on the comprehensive characterization factor, the fracture porosity, the gas saturation, and the lower limit of the actual permeability, including: For any given oil well to be evaluated, calculate the comprehensive characterization factor of each segment of the oil well to be evaluated, the fracture porosity of the sandstone and mudstone reservoir, the gas saturation and the actual permeability. For any segment of any well to be evaluated, if the comprehensive characterization factor, fracture porosity, gas saturation, and actual permeability of the segment are all greater than the lower limit determined based on the already exploited sandstone and mudstone, the segment is identified as a geological sweet spot in the well to be evaluated.

3. The method according to claim 1, characterized in that, The process of determining the engineering sweet spot of the well to be evaluated based on the compressibility index of well logging includes: Calculate the compressibility index of multiple segments of the already mined sandstone and mudstone, as well as the compressibility index of multiple segments of the oil well to be evaluated. The lower limit value for the compressibility index is determined based on the compressibility index of multiple segments of the already mined sandstone and mudstone. For any segment of any well to be evaluated, if the compressibility index of the segment is greater than the lower limit of the compressibility index, the segment is identified as the engineering sweet spot of the well to be evaluated.

4. The method according to claim 1, characterized in that, Calculate the comprehensive characterization factor RC for each segment according to formula (1): RC=SP*1-R|*φ (1) Where Φ is the porosity of the sandstone and mudstone reservoir that has been mined, which is a percentage; SP is the sorting coefficient of the pore throat; and R is the average pore radius of the rock, in μm.

5. The method according to claim 1, characterized in that, Calculate the crack porosity of each segment according to formula (2): Among them, R mf R represents the resistivity of the mud filtrate, expressed in Ω·m. LLS Shallow lateral, unit is Ω.m, R LLD For deep lateral direction, the unit is Ω·m, φ 裂缝 The value represents the crack porosity, in percentages (m). f This represents the crack porosity index.

6. The method according to claim 1, characterized in that, Calculate the gas saturation of each segment according to formula (3): Where n is the saturation index, S w The water saturation level is expressed as a percentage. R represents the clay content as a percentage. sh The resistivity is the amount of clay content, expressed in Ω·m, φ. c R represents the inorganic porosity as a percentage, α is the lithology coefficient, and R is the inorganic porosity. w R represents the resistivity of formation water, expressed in Ω·m. t The value represents the formation resistivity, expressed in Ω·m.

7. The method according to claim 1, characterized in that, The compressibility index Y of each segment is calculated according to formula (4). 可压性 : Y 可压性 =0.21*Vp+3.51*Vs-1.68*YM+2.65*PR (4) Among them, V p The longitudinal wave time difference is expressed in μs / ft, V. s , where is the transverse wave time difference in μs / ft, YM is Young's modulus in MPa, and PR is Poisson's ratio in MPa.

8. A sweet spot evaluation device for tight sandstone geological engineering based on conventional well logging, characterized in that, include: The experimental data acquisition module is used to acquire well logging curve data and experimental analysis and testing data of the already mined sandstone and mudstone. The data calculation module is used to calculate the comprehensive characterization factor of each segment of the well logging and the fracture porosity of the sandstone and mudstone reservoir based on the well logging curve data and the experimental analysis and testing data, so as to determine the lower limit values ​​of the comprehensive characterization factor and the fracture porosity respectively. The comprehensive characterization factor is used to characterize the micropore structure of the sandstone and mudstone reservoir rock. The larger the comprehensive characterization factor, the larger the pore throat, the more regular the pore shape, and the better the pore-permeability relationship. The module determines the gas saturation of each segment of the well logging based on the Simon formula. The module obtains the actual permeability of multiple segments of the well logging and performs correlation analysis based on the actual permeability to determine the lower limit value of the actual permeability of the multiple segments. The geological sweet spot determination module is used to determine the geological sweet spot in any oil well to be evaluated based on the comprehensive characterization factor, the fracture porosity, the gas saturation, and the lower limit of the actual permeability. The engineering sweet spot determination module is used to determine the engineering sweet spot of the well to be evaluated based on the compressibility index of the well log. The effective reservoir section determination module is used to determine the effective reservoir section of sandstone and mudstone in any well to be evaluated based on the engineering sweet spot and the geological sweet spot.

9. A sweet spot evaluation device for tight sandstone geological engineering based on conventional well logging, comprising a processor and a memory, characterized in that, The memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, it implements the steps of the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that, when executed by a processor, cause the processor to perform the steps of the method as described in any one of claims 1 to 7.

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