Oil and gas potential of the south Turgay basin

Background. The South Turgay basin has been extensively studied using geological and geophysical methods. To date, the discovery of large oil and gas deposits in its structural traps seems impossible. The deposits, which have been under development for a long time, demonstrate the trend towards depletion. Therefore, a search and exploration of non-anticlinal traps is becoming an important source of hydrocarbon reserves. Aim. To identify zones of non-anticlinal reservoirs and traps. Materials and methods. On the basis of three main criteria for predicting the development of nonanticlinal traps (stratigraphic, lithofacies and structural-tectonic), this paper presents the forecast zones for the development of non-anticlinal traps with oil and gas potential, taking into account the facies diagnostics of the deposits. Results. The traps of regional pinching-out, as well as possible traps of erosion-accumulative and accumulative subgroups, are predominantly developed in the trough. The traps of the regional pinch-out subgroup are most widespread in the Aryskum and Bosingen graben synclines. The traps of the accumulative subgroup are predicted mainly in the Bosingen and Akshabulak graben synclines. Conclusions. According to the obtained results, the South Turgay Basin possesses a significant oil and gas potential in non-anticlinal traps. Lithological reservoirs with thick and widespread mudstones confined to the Jurassic deposits are of particular interest.