Abstract:

The Dongying Formation in Laoyemiao region consists of fan-delta,lake delta,neritic subaqueous fan and subaqueous gravity flow and lake depositional systems.Oil and gas are mainly distributed in the frontal zones of fan-delta and fan detaic plain.The subaqueous distributary river channels and river mouth sand bars in deltaic frontal zone are the main reservoir sandbodies.The intergranular soluted pores are the main preserving spaces of the reservoirs which decreased with the increase of buried depth,the porosity and permeability are of low mid type.Hydrocarbon accumulation is controlled by sedimentary facies zone.It is pointed out that the exploration of Ed₃ condensed oil and gas pools in north Laoyemiao region should be taken into account,and that Ed₁ and Ed₃ of the southern part of Laoyemiao region would be the main targets for exploration in future.

Key words: Laoyemiao region, Dongying Formation, depositional system, reservoir sandbody, hydrocarbon enrichment, oil-gas bearing facies zone