Geochemical characteristic study of oil gas and source rocks in Well Pushen 8 in Dongpu depression.

Menggangji sag is a region least explored in Dongpu depression. However, not only commercial oil flow has been obtained but a stratigraphic sequence has been revealed in Well Pushen 8 drilled in 1997. A study on potential of hydroca r bon generation in source rocks, characteristic of crude oil and mother substance of oil and gas shows that there are 3 sets of source rocks: immature low matur e source rocks in Member S 1; mature highly mature source rocks in Member S 3; and highly mature source rocks in Permian. The peak generation period of hydr ocarbon was in the phase of S 3 deposition. Crude from Well Pushen 8 is of high ly matured one. Mother substance of such crude are derived from a hybrid organic matter containing high plants and low aquatic organisms. This crude is from S 3 source rocks. Results of exploratory drilling and study show that Member S 3 in Mengguangji sag has relatively better hyd rocarbon generation conditions. This sag has a relatively better source backgrou nd and is an exploratory target that should be stressed.