Nonproducing Carboniferous may have potential in Qaidam basin, NW China

摘要

The Qaidam basin is one of three main oil and gas basins in Northwestern China, but its Carboniferous, formerly thought as a part of the metamorphic base of the basin, is a frontier formation without any oil and gas reserves or production.A large number of geological surveys have indicated most Carboniferous rocks to be sedimentary rocks with medium thermal evolution and hydrocarbon generation potential.More than 10 oil sands (bitumen deposits) were firstly discovered in Carboniferous outcrops in 2008-10. Geo-chemical evidence shows that these oil sands originate from Carboniferous source rocks. Using geochemical and analog methods, Carboniferous petroleum resources in place were calculated to be 4.5-5.3 billion bbl in the Qaidam basin. Its oil and gas resource richness is moderate compared with that of Carboniferous formations of other basins in the world. Hence, it is probable for the Carboniferous to become a successor of oil and gas productive formations in the Qaidam basin in the future.