The Progress of Carboniferous Oil and Gas Investigation and Assessment in Qaidam Basin

The Qaidam Basin is one of China’s large petroliferous basins,and oil and gas have been found mainly in Mesozoic and Cenozoic strata.Through the investigation of Carboniferous oil and gas resources of Qaidam Basin in recent years,the authors have confirmed that the Carboniferous strata are widely distributed and in large thickness in the Qaidam Basin.The Carboniferous distribution is 10 km2.The area greater than 1000 m in thickness is 5.71 km2.Carboniferous strata having well-developed source rocks are widely developed in the thick layer of oil sands,suggesting that Carboniferous strata have a good capability for hydrocarbon generation and oil and gas migration process.Carboniferous tectonic deformation occurred mainly in late Neogene,and prior to this period,tectonic deformation was weak,which was favorable for Carboniferous hydrocarbon preservation. Preliminary evaluation of the Carboniferous oil and gas resources in Qaidam Basin amounts to 6.14×108-7.23×10 8t,implying that Qaidam Basin has large Carboniferous oil and gas resource potential and serves as a new area for strategic breakthrough in oil and gas resources exploration.