Analysis of hydrocarbon resource potential in Awati Depression of Tarim Basin

The degree of petroleum prospecting in the Awati Depression is the lowest comparing with that in platform depression areas of the Tarim Basin. Some oil and gas shows such as the Wuluqiao oil show and the Silurian asphaltic sandstone were found in the depression and its surroundings. Based on the studies of regional tectonic setting and its evolution, depositional environments and geochemical characteristics of the main source rocks, two different kinds of principle source rocks with different sedimentary backgrounds and geochemical features, deve-loped in lagoonal facies and continental shelf and slope facies respectively, were determined. Source rocks deve-loped in the Lower Cambrian Yuertusi Formation, the Middle and Upper Ordovician Saergan Formation and Yingan Formation were dominated by slope facies and showed extra-high organic content which was related to ascending current. And the Middle and Lower Cambrian source rocks with relative high organic content were developed in lagoonal facies. The sedimentary models for the formation of quality source rocks and the identification marks for depositional environments were proposed. According to the studies of sequence stratigraphy, seismic facies and depositional facies, the identification and prediction of source rocks confined by seismic and depositional facies under sequence stratigraphic framework were carried out. On the basis of dissecting of typical reservoir and synthetic analysis of hydrocarbon accumulation, the potential targets for petroleum exploration were indicated in the Awati Depression and its surrounding areas.