Appraisal of the transient electromagnetic method in the near field zone for oil and gas exploration within the south of the Siberian craton

Abstract

The paper describes the horizontal and vertical resolution of the transient electromagnetic method in the near field zone (TEM). Possible ways of their numerical evaluation using mathematical data modeling are considered. The most attention in the article is devoted to a new modern method for the numerical evaluation of the TEM capabilities (in particular, vertical resolution), based on the multi-iterative inversion of noisy synthetic data. The key point of the proposed approach, which affects the reliability of the results, is the building of a physical-geological model area to study. The physical-geological model is compiled using a priori information about the geological structure of the area, petrophysical data and well-logs. Examples of evaluating capabilities of the TEM for oil and gas exploration are given. Three averaged physical-geological models of large oil and gas structures in the south of the Siberian craton (Nepsky and Kamovsky arches, Angar-Lena stage) are examined. These areas are prospective for oil and gas accumulations in the subsalt part of the section. Shown that the TEM is most effective in the geological settings of the Nepa arch.Through the application of the proposed approach, it became possible to numerically assess the risks of an erroneous geological prediction when interpreting the TEM data.