摘要：On the basis of core description and logging analysis, the sedimentary structure, logging facies, microfacies types and reservoir distribution of the Second Member of Shuangyang Formation of Changchun Oilfield in Yitong Basin are studied. The results show that the Second Member of Shuangyang Formation in the study area mainly develops conglomeratic sandstone, coarse sandstone, fine sandstone and mudstone, with low composition maturity, low textural maturity, poor sorting, poor roundness. A variety of bedding structures and scour filling structure developed in study area. The fan delta front subfacies can be further divided into five microfacies, including underwater distributary channel, point bar, sheet sand, overbank sand and underwater interdistributary. Underwater distributary channel is the skeleton sand body, and it is ribbon-shaped. Point bar is lingual or oval stacking body in the center of the underwater distributary channel, and it is the main reservoir in study area. The sand body was stripped from north west to south east, with the thickness of sand body increasing first then decreasing and the width of the channel widening first then narrowing. On the whole, the water energy of underwater distributary channel increases first then decreases, which reflects the transition from recession to transgression.
