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AUTOMATING THE BED BOUNDARIES DETECTION PROCEDURE FOR 2D INVERSION OF OIL AND GAS WELL RESISTIVITY LOGS

A. M. Petrov, K. N. Danilovskiy, O. O. Asanov, I. A. Moskaev, S. A. Primakov

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

Inversion of resistivity logs based on two–dimensional axisymmetric models of the medium is a reliable way to determine the electrical resistivity of reservoir beds – a characteristic closely related to their fluid saturation. Possibilities of wide application of such approach are limited today, first of all, by the laboriousness of creating an initial approximation of the geoelectric model of the medium, the key stage in the construction of which is the splitting of the studied section into relatively vertically homogeneous beds. The paper presents a new algorithm for bed boundaries detection, which is focused on solving the problem of creating an initial geoelectric model of the medium for two-dimensional inversion of resistivity logging data. The developed algorithm is a variation of the gradient approach and, its software implementation is characterized by performance sufficient to process extended logging intervals in an interactive mode. Capabilities of the algorithm are demonstrated by comparing with the results obtained by algorithms implemented in common well log data processing and interpretation packages, as well as on the results of two-dimensional inversion of practical data with quantitative estimates of the bed boundaries positioning accuracy.

Keywords: geophysical well logging, automated data processing, bed boundaries detection, sectional layering, two-dimensional inversion of resistivity logs, terrigenous deposits, Bazhenov Formation.

DOI 10.20403/2078-0575-2022-11с-87-95

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