Jurassic Lacustrine Source Rock Characteristics and Its Petroleum Geological Significance in the Southeast Depression of Tarim Basin, China

Based on results from the field geology investigation, seismic interpretation, sedimentary analysis, and a great number of samples tests, the semi-deep lake facies were developed in the Kangsu Formation of the Lower Jurassic in Washixia sag and in the Yangye Formation of the Middle Jurassic in Minfeng sag and Washixia sag. The source rocks of Jurassic lacustrine facies were developed on the top of the Yangye and Kangsu Formations, mainly distributed in the south central part of Washixia sag and Baxikangsulake-Pulu area of Minfeng sag. The Lacustrine source rocks are mainly Mudstone with great thickness, organic matter of type II–III, high organic matter abundance, TOC of generally more than 2.0 %, and PG in the range of 2–6 mg/g. With the thermocompression simulation experiment, the source rock generated hydrocarbon up to 300 mg/g TOC. The source rock is good at the thermal evolution stage of low mature to mature. We conclude that the source rocks of the Yangye and Kangsu Formations in the central south of Washixia sag have better exploration potential with good hydrocarbon-generating conditions.