Triassic sequence stratigraphic characteristics study on Hashan area

By using the theory of sequence stratigraphy,through drilling,logging,seismic,core data analysis of Triassic system in Hashan area,one class-I and two class-III sequence interfaces have been identified out.The Triassic system can be divided into three class-III sequence interfaces(TSQ1,TSQ2,TSQ3)and six system domains.In TSQ1,it mainly developed alluvial fan-fan edge-fan delta plan sedimentary system.In TSQ2,it mainly developed fan delta front-plan sedimentary system.In TSQ3,it mainly developed shore-shallow lacustrine sedimentary system.The gravel strata from alluvial fan in TSQ1,mainly developed on the edge of the basin,with the combination of faulting or unconformity and it can still be good reservoir.Fan delta front distributary channel in TSQ2 was the most favorable reservoir facies belt.