To the issue of oil and gas potential in the decompression zones of the Dnieper-Donets depression

Abstract

Formulation of the problem. Currently, interest in the foundation as a gas and oil field facility has increased significantly. The low efficiency of oil and gas exploration in the basement rocks is usually explained by the absence of a generally accepted hypothesis about the genesis of oil and gas and as a result of migration and accumulation of hydrocarbons. One of the main factors of accumulation is the presence of decompression zones of the foundation, as potential hydrocarbon traps. The article is devoted to the problem of identifying oil and gas bearing zones of foundation decompression. Analysis of recent research and publications. A number of scientific articles on the composition, age, structure and oil and gas potential of the foundation are analyzed. The first step in identifying decompression zones is to conduct gravimetric and magnetic surveys and apply various techniques to interpret the resulting mathematical model of the wave field pattern in order to localize the sources of its anomalies. Identification of previously unresolved parts of a common problem. In order to save money when conducting prospecting and exploration for oil and gas, the foundation proposes an improvement in the methodology for separating gas-bearing “vaulted” parts of decompression zones. Formation of the purpose of the article. The aim of the work is to establish a seismic pattern of anomalies in the geophysical fields of the base decompression zones. The object of research is the zone of decompression of the foundation on the northern side of the Dnieper-Donets depression. The subject of the study is a seismic drawing of the anomaly of the geophysical field of the gas-bearing zone of decompression of the foundation of the Rozsoshinsk structure. Report of the main material. The article analyzes a few materials to identify areas of base decompaction in various oil and gas regions. It was found that for localization of decompression zones, the Berezkin “singular points” method and the correlation method of separation of geophysical anomalies are most effective. The essence of these methods is a kind of filtering of field anomalies, where against the background of the "structural" factor, one can distinguish the "non-structural factor", i.e. decompression zone. This zone in wave fields (∆g and ∆Т) is fixed by a seismic pattern, where minima are usually fixed over hydrocarbon accumulations in relation to contouring maxima. Based on the results of the application of these methods, the structure-testing ground of the gas-bearing decompression zone is established. As an illustrative example of the successful localization of ∆g and ∆Т, data are presented on modeling the foundation softening zone in one of the oil and gas regions of the northern side of the Dnieper-Donets depression.