Tectonics and deep structure of Yugan-Koltogor zone of West Siberia Platform foundation

Abstract

Research subject. The deep structure of the Yugan-Koltogor zone located in West Siberia was investigated with the purpose of detecting prospective oil and gas bearing areas.

Materials and methods. The methods of lineament extraction and the computer modelling of rock density were employed. Lineament extraction was conducted on the basis of geophysical data, including detailed (1 : 200 000) maps of anomalous magnetic and gravity fields. In order to detect faults, telemetering methods were used, along with the results of studies conducted to investigate core materials from wells in the region. The modelling of the deep structure of the pre-Jurassic basement was performed on the basis of its geological map by solving a direct problem while fitting geological body densities.

Results. Six largest faults of the Yugan-Koltogor zone identified on the geological map by a special sign “deep faults and regional schistosity zones” are of particular interest as possible oil bearing areas.

Conclusions. The modelling of the deep structure of the pre-Jurassic basement of the West Siberian Platform has shown the granite decompaction areas of the Yugan zone to be highly promising in terms of oil and gas deposits.