Jurassic distribution and bedrock lithologic prediction of Dongping area, Qaidam Basin

The discovery of natural gas from Dongping 1 Well in Dongping area has triggered the large-scale exploration of bedrock gas reservoirs in Qaidam Basin. Plenty of exploration and research work shows that the bedrock reservoirs in Dongping area were mainly sourced from Jurassic coal type gas and Tertiary oil type gas, and that the Jurassic hydrocarbon source rocks and bedrock reservoirs in Dongping were accumulated and entrapped in granite and gneiss after upward migration in the fracture system and lateral migration in sand pores. However, the unclear Jurassic distribution and basement lithology have limited the exploration of Dongping bedrock gas reservoirs. The combination of CEMP study of piedmont and the comprehensive analysis of magnetic data can define the distribution characteristics of the Jurassic strata and determine the rock characteristics of Dongping-Lenghu(Cold Lake) area, and the result coincides well with drilling. The results achieved by the authors have practical significance for guiding the exploration of bedrock gas reservoirs in this area.