Download PDF

IDENTIFICATION OF THE RESISTIVITY ANNULUS DURING THE JOINT INVERSION OF GALVANIC AND ELECTROMAGNETIC LOG SOUNDING SIGNALS MEASURED SIMULTANEOUSLY AND AT DIFFERENT TIMES

K. V. Sukhorukova 1, G. V. Nesterova 1, S. A. Primakov 1,2

1 A.A.Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, 2 Novosibirsk State University, Novosibirsk, Russia

The possibility of identifying the resistivity annulus by signals of lateral log sounding and electromagnetic log sounding with their joint numerical inversion is investigated. The radial profile of electrical resistivity (ER) is calculated for different times after drilling in the simulation program for the drilling mud filtration into a porous permeable reservoir. For this continuous profile, signals of electric logging in reservoir of unlimited thickness are calculated. Temporal variation of the ER radial distribution in a permeable reservoir leads to a corresponding change in sounding curves, which may limit the reliability of determining the parameters of the geoelectric reservoir model with a joint numerical inversion of electrical and electromagnetic logging data measured at various times. Radial profiles of ER calculated during the drilling mud filtration process modeling are confirmed by practical data in the interval of Cretaceous reservoirs BS10 and BS11 of the Surgut arch.

Keywords: lateral log sounding, high-frequency electromagnetic log sounding, electrical resistivity, radial distribution, joint numerical inversion, geoelectric model.

DOI 10.20403/2078-0575-2022-11с-77-86

​ ​​​​​​​​