THE HYDROCARBON-EXPULSION CHARACTERS OF LZ DEPRESSION IN LDW SEA AREA

In LiaoZhong depression,there were four sets of hydrocarbon source rocks;they were all developed in the paleogene.Each of them had different contribution to the oil and gas accumulation in this depression,based on the source rock evaluation we used the theory of hydrocarbon expulsion threshold and the hydrocarbon-generating potential method to research the hydrocarbon expulsion characteristics of upper Ed2,Ed3,Es1 and Es3 source rocks in the Paleogene,and evaluate the strength of their expulsion.The study found different sets of source rocks for hydrocarbon expulsion threshold were the depth of 2600m,2900m,2700m and 2500m or so,the calculation of the strength of hydrocarbon expulsion shows that Es3 has the highest average value.Based on the thickness of the various sets of source rocks,the parameters of hydrocarbon source rock evaluation and the parameters of the current strength of hydrocarbon expulsion comprehensive analysis,the source rock Es3 in LiaoZhong depression contributed the most for hydrocarbon accumulation in LiaoZhong depression,is main source rock of LiaoZhong depression.