Reduction of uncertainty at detection of gas saturated anomalies by technology of AVO-analysis on the Vilaysky sinklesis territory.

This article discusses methods of complex analysis for determining future levels of gas content for example, one of the areas of Eastern Siberia. Previously, carried out 2D seismic work and drilling data, the square was revealed and prepared for drilling gas deposits in the Permian-Triassic complex. With the aim of examining and detailing of structural-tectonic structure of the area was conducted 3D seismic survey, which resulted in the established block structure of the area and detailed structure of promising and potentially promising floors. Seismic wave field is characterized by the presence of «bright spots», due to the contrast of the physical parameters of coal and gas-bearing sandstones in the host rocks of Permian-Triassic and Cretaceous complexes, in connection with which was given the task of performing a comprehensive analysis to separate anomalies «coal», «gas» and identify gas deposits. This article describes the technology of AVO attribute analysis using petrophysical trends established on diagrams of logs in intervals of chalk and upper Permian, the rationale for selection of anomalies caused by traps HC.

Author – Feoktistova O.V.