Determination of Implicit Oil-and-Gas-Bearing Sand Intervals by Statistical-Correlation Interpretation of GWS Data; Seismic Instruments; Vol. 61, iss. 4
| Parent link: | Seismic Instruments.— .— New York: Allerton Press, Inc. Vol. 61, iss. 4.— 2025.— P. 326-333 |
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| Κύριος συγγραφέας: | |
| Περίληψη: | Title screen The relevance of the topic is related to the problem of searching for missed productive low-resistance sandy intervals, whose occurrence is caused by the presence of surface electrical conductivity within the pores of sandy rocks. The purpose of this study was to briefly demonstrate the results of applying the method of statistical-correlation interpretation of geophysical well-logging data to search for implicitly missed low resistivity oil and gas reservoirs. Method. This paper briefly describes the method of statistical-correlation analysis of well-logging data. It presents the theoretical physicochemical and formal-logical justifications of this interpretation. This approach is based on the principles of correlation of measured and calculated geophysical and petrophysical parameters of the investigated sand interval, which vary along the well section. These changes are caused by dominant geochemical processes of superimposed epigenesis in a certain local interval in the deep fluid penetration area. The product of the approximation coefficient and the statistical interval parameter for two samples of measured parameters corresponds to the statistical intensity of transformation processes within sand intervals. By using the method of statistical-correlation interpretation of well logs for sandy formations based on a standard set of geophysical well-logging data it is possible to determine the intensity of secondary processes such as pyritization, kaolinitization, pelitization, carbonatization, and the formation of a double electric layer in clays. These processes may cause an implicit decrease in the electrical resistivity of the rock. Certain boundary values of the intensity of these secondary processes can serve as an indicator of the presence of hydrocarbons in these formations. Results. The validity of the statistical-correlation method for interpreting well-logging data was confirmed when comparing the calculation results of the intensity of transformation processes with the results of petrographic core analysis. By determining the intensity of mineral transformation processes that affect the increase in the surface electrical conductivity of sandy rocks in the Nizhneluginetskaya well, Jurassic low-resistivity promising reservoirs were identified. The oil potential of these reservoirs was confirmed by the results of core alcohol–benzene extraction. In the Vakh field, the results of identifying promising Cretaceous reservoirs based on the statistical-correlation interpretation of geophysical well-logging data were confirmed by formation tests. Oil was obtained from the previously missed sandy interval. At the same time, secondary carbonatization was an indicator of the presence of hydrocarbons with a probability of 80%. Conclusions. If we use well-logging data (both old and new databases) to calculate the intensity of geochemical processes as an indicator of the presence of hydrocarbons, as well as the boundary values of these intensities in the sandy formations, it is possible to reveal implicitly missed low-resistance oil and gas reservoirs with an ~80% probability Текстовый файл AM_Agreement |
| Γλώσσα: | Αγγλικά |
| Έκδοση: |
2025
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| Διαθέσιμο Online: | https://doi.org/10.3103/S0747923925700434 |
| Μορφή: | Ηλεκτρονική πηγή Κεφάλαιο βιβλίου |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=685651 |
| Περίληψη: | Title screen The relevance of the topic is related to the problem of searching for missed productive low-resistance sandy intervals, whose occurrence is caused by the presence of surface electrical conductivity within the pores of sandy rocks. The purpose of this study was to briefly demonstrate the results of applying the method of statistical-correlation interpretation of geophysical well-logging data to search for implicitly missed low resistivity oil and gas reservoirs. Method. This paper briefly describes the method of statistical-correlation analysis of well-logging data. It presents the theoretical physicochemical and formal-logical justifications of this interpretation. This approach is based on the principles of correlation of measured and calculated geophysical and petrophysical parameters of the investigated sand interval, which vary along the well section. These changes are caused by dominant geochemical processes of superimposed epigenesis in a certain local interval in the deep fluid penetration area. The product of the approximation coefficient and the statistical interval parameter for two samples of measured parameters corresponds to the statistical intensity of transformation processes within sand intervals. By using the method of statistical-correlation interpretation of well logs for sandy formations based on a standard set of geophysical well-logging data it is possible to determine the intensity of secondary processes such as pyritization, kaolinitization, pelitization, carbonatization, and the formation of a double electric layer in clays. These processes may cause an implicit decrease in the electrical resistivity of the rock. Certain boundary values of the intensity of these secondary processes can serve as an indicator of the presence of hydrocarbons in these formations. Results. The validity of the statistical-correlation method for interpreting well-logging data was confirmed when comparing the calculation results of the intensity of transformation processes with the results of petrographic core analysis. By determining the intensity of mineral transformation processes that affect the increase in the surface electrical conductivity of sandy rocks in the Nizhneluginetskaya well, Jurassic low-resistivity promising reservoirs were identified. The oil potential of these reservoirs was confirmed by the results of core alcohol–benzene extraction. In the Vakh field, the results of identifying promising Cretaceous reservoirs based on the statistical-correlation interpretation of geophysical well-logging data were confirmed by formation tests. Oil was obtained from the previously missed sandy interval. At the same time, secondary carbonatization was an indicator of the presence of hydrocarbons with a probability of 80%. Conclusions. If we use well-logging data (both old and new databases) to calculate the intensity of geochemical processes as an indicator of the presence of hydrocarbons, as well as the boundary values of these intensities in the sandy formations, it is possible to reveal implicitly missed low-resistance oil and gas reservoirs with an ~80% probability Текстовый файл AM_Agreement |
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| DOI: | 10.3103/S0747923925700434 |