Being controlled by Lanliao fault on the margin

Qianliyuan depression continues developing to provide the necessary foundation of the formation of deep basin gas accumulations. Well-developed hydrocarbon source rocks occur in Lower Tertiary in the depression

which has high evolution degree and abundant gas source.Tight sand reservoirs with low-porosity and low-permeability develop in the 3rd and 4th sub-members of the third members

Shahejie Formation

which are favorable for the formation of deep basin gas accumulations.Gas accumulations

characterized by “inverted gas and water”

anomalous high-pressure

long gas-bearing interval and low production

as well as unrelated with structure

etc.

have been discovered around Qianliyuan depression. Dongpu depression is a typical “fault-sag” type deep basin gas among the non-marine fault-depression basins

and the slope zone surrounding the depression will be favorable target for exploration in the future.