| The second member of Liushagang Formation was the principal layer of source rocks, in this area the lake remained as a starved basin; the characteristics of seismic reflection were largely parallel, sub weak amplitude, discontinuous emission characteristics. TOC was generally greater than 1.5%; the kerogen type major was Ⅰ and Ⅱ type; it might be good source rocks. According to the result of the simulation, Weixinan sag in Liushagang Formation, source rock oil yield was 11.4 billion tons, gas yield was 22.31 hundred billion m3, total hydrocarbon generating intensity basically exceeded 5 million tons/km2; in plane, depression A hydrocarbon was accounted for 41%, the depression B was accounted for 54% of the hydrocarbon generation. Vertically, the hydrocarbon generation amount for the second member of Liushagang Formation run up to 80%, the main source contributor. In Weixinan sag, there were two hydrocarbon generation peaks: the depositional period of Weizhou Formation and the period of Xiayang to present depositional period. According to the oil and gas migration and accumulation unit classification results, and development characteristics of sand body framework and fault distribution,the authors might obtain the most favorable hydrocarbon accumulation zone. |