Sedimentary Microfacies and Evolution of the Lower Karamay Formation in mid and east of 7th Block,Karamay Oilfield

In mid and east of 7th block,Karamay Oilfield,the sedimentary characteristics of the Lower Karamay Formation were not recognized clearly,which impressed exploiting the remaining oil and deploying the plan.Through the analysis of depositional environment,core facies and electrofacies,it is concluded that piedmont pluvial facies were developed during the deposition of the Lower Karamay Formation.On the basis of this area,four subfacies were divided(the inner belt of root fan,the outer belt of root fan,middle fan and fan edge).In bottom section of formation,the glutenite of root fan is dominant in the facies distribution of plane;In middle section,the glutenite of middle fan interbed mudstone is dominant;In top section,the mudstone intersperse with glutenite is predominant.Based on the piedmont pluvial facies,eight microfacies were divided(the gravel of channel flow,the gravel of laminar flow,sheetflood sand,sheetflood fine grain,braided channel,runoff channel,overflow sand and overflow fine grain).And the characteristics of petrology,construction,structure and electric were described.The distribution of facies in plane and certical evolution were indicated,and the sedimentary model of the area was established.