Abstract:

Through the analysis on reservoir formation factors，such as source condition，sedimentary reservoir characteristics，migration path and space-time coupling，and by means of the correlation and comparison on multiple geological parameters from reservoir and failed reservoir,  the reservoir accumulation mechanism and main factors are clarified herein for the second member of Shawan Formation in Chepaizi uplift. It is revealed that，the hydrocarbon in the study area is mainly from the Jurassic and Permian source rocks in Changji sag. The underwater distributary channel sandstone and beach bar sand holy are the most favorable storage rocks of reservoir. The stable distribution，good physical properties，and great thickness of sand stone in the first number of Shawan Formation and fractures acted as the conduit system of net-carpet model. Thanks to the favorable time -space coupling，the study area is characterized by gentle slope with remote source，lateral migration along thick sandbodv，and low to moderate charging.  The lithology，porosity and permeability of reservoir control the oil and gas-filling.  Three factors，the fault clip in shallow formation，distance between trap and thick sandstone in the first number of Shawan Formation，and total thickness of interlayer mudstone，control the oil and gas transporting efficiency and trap oil probability.

Key words: net-carpet conduit, second member of Shawan Formation, main reservoir accumulation factor, Junggar Basin, Chepaizi uplift