The study analyzed the sedimentary facies of the 2nd member of Fuyu Reservoir in a specific area. By examining core samples and logging data, researchers found that shallow-water delta sedimentary facies are present, with delta plain distributary channels and underwater distributary channels of the delta front being the main types of sand bodies. Over time, the sedimentary water became gradually shallower, with the optimal period for reservoir sand body development occurring during a specific time period.