Features of the composition of gas sorbed in the rocks of the upper part of the sedimentary cover section

Abstract

The topicality of the article is determined by the insufficient reliability of geochemical oil and gas exploration data for the localization of petroliferous geological objects. Geochemical surveys are carried out to mapping hydrocarbon anomalies caused by vertical migration of fluid from hydrocarbon deposits. Practice shows that not all anomalies in the content of hydrocarbons in the near-surface environment are related to the oil-bearing capacity of a given subsoil area. Therefore, when interpreting the data of geochemical oil and gas prospecting surveys, it is necessary to take into account not only quantitative indicators (namely, content of hydrocarbon gases on the surface), but also the composition of the gas sorbed by the near-surface substrate. The purpose of the article is to determine the composition of the dissipated gases in the rocks of the upper part of the section, to reveal the inter-component relationships, and, on this basis, to determine the genesis of each gas component sorbed by the rocks of the upper part of the section. To solve this problem, statistical processing of data on the component content of gas from core degassing of shallow (up to 30 m) wells drilled in the petroliferous territory of the north of Western Siberia was carried out. The obtained results confirmed the genetic heterogeneity of dissipated hydrocarbons and inorganic gases in the upper part of the sedimentary cover.