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GEOELECTRIC MODELS OF CRETACEOUS RESERVOIRS OF WEST SIBERIA BY THE RESULTS OF INTEGRATED INTERPRETATION OF ELECTRIC LOG DATA

K. V. Sukhorukova, A. M. Petrov, O. V. Nechaev

A. A. Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia

The results of testing a new software-methodological complex of numerical inversion on the data of electrical logging, measured in vertical wells in the intervals of Cretaceous reservoirs in West Siberia. They are characterized by a complex radial profile of electrical resistivity, electrical anisotropy and polarizability. As a result of the quantitative interpretation of a set of electrical (LLS) and electromagnetic (VEMLS) logging data, realistic geoelectric models of sedimentary deposits of the Latitudinal Ob Region were constructed, and the relationships between electrical anisotropy and dielectric constant with a thin-layered structure and clayiness of rocks were established. The software developed at IPGG SB RAS for the joint numerical inversion of the LLS and VEMLS signals, as well as the method for the quantitative interpretation of the data of these methods, provide the construction of a detailed geoelectric model of sedimentary deposits, which takes into account the influence of host rocks, zones changed by the filtration of the drilling mud, wells with mud and sizes of logging equipment. As a result, the electrical resistivity of thin reservoir layers surrounded by contrasting host rocks is specified, the electrical anisotropy is revealed, and the dielectric constant is estimated.

Keywords: electric logging sounding, joint numerical inversion, two-dimensional geoelectric model, electrical resistivity, dielectric constant, terrigenous section.

DOI 10.20403/2078-0575-2020-3-77-86