Gas hydrate sources in Wuli-Kaixinling permafrost, southern Qinghai province

Based on the past two years' data on gas source survey in compliance with the National Thematic Project of Gas Hydrate Resources' Exploration and Test-Production Engineering in the Wuli-Kaixinling permafrost of the southern Qinghai province, organic geochemical indicators were analyzed on the hydrocarbon (gas) source rocks of the Nayixiong Formation in the Upper Permian Wuli Group and the Bagong Formation in the Upper Triassic Jiezha Group. Results showed that organic matter contents were at moderate levels in the hydrocarbon (gas) source rocks of the two formations. The main organic matter was type III with high maturity. For most samples, organic matter was mature or over-mature, at the wet to dry gas phase. The source rocks produced a large amount of hydrocarbon gases to meet the needs of gas hydrate formation. Mudstones in the Nayixiong Formation in the Upper Permian Wuli Group and limestones in the Bagong Formation in the Upper Triassic Jiezha Group worked as major gas source rocks for gas hydrate formation.