GEOCHEMICAL CHARACTERISTICS OF CRUDE OIL AND THE OIL SOURCE ANALYSIS IN THE JZ25-1 AREA, LIAODONG BAY

In JZ25-1 Liaodong Bay ,the crude oil of Es2 and Es3 have the characteristics of low sulfur, high wax, condensate~light oil .Crude oil has not been biodegradation and have a slight advantage odd-even predominance of n-ammacealkanes. Steranes and Terpanes characterized of crude oil showed a medium abundance of grane, 4 - methyl steranes and dinosteranes, high abundant the fingerprint of rules steranes C27,C28,C295α(H), 14α(H), 17α(H) dissymmetry V-type distribution , The crude oil was mature from sterane isomerization parameters. The main source of crude oil to restore the environment the freshwater-brackish water, reductive, a minor abundant Dinoflagellates, forming mainly source of organisms from aquatic organic phase. The main source of JZ25-1 region Es2 Es3 normal crude oil was from the source rocks Es3 and a small amount from Es1 source rocks in Liaoxi depression. Es2 condensate oil, a low maturity, mainly source, was form Liaoxi Depression Es1 source rocks and a small amount was from Es3 source rocks of Liaoxi depression.