King Of Ansai Oilfield Kiln District 6 < Sub > 1 < / Sub > Sedimentary Microfacies In The Reservoir Group Research

This paper studies the Chang61oil reservoir beds of Yanchang formation in Wangyao district in Ansai oilfield.based on sedimentology,geological logging,reservoir geology and geological background.stratigraphic cycles-thickness division method is used to divide the stratum,making the result true and reliable.The types of sedimentary microfacies and evolution are divied on the basis of lithological characteristics,fossils and logging facies.The achievement can be used in injection development and favorable areas forecast.It is concluded that Chang61oil-bearing formation in the studied area is interpreted to be a river-dominated delta deposited in lacustrine environment,consisting of underwater distributary channel,interdistributary bay,front santsheet and natural levee.The underwater distributary channel sand bodies constitute the dominated reservoir.By the influence of river course,underwater distributary channel distributes alternating with interdistributary bay which forms the principal source-reservoir-seal assemblage mode.The sedimentation forms the foundation of sandstone reservoir,decides its clastic constituents,texture and controls the distribution of sand body.The underwater distributary channel sand bodies which should be the main destinations of exploration of this area in the near future is not merely good physical property.