Sedimentary Characteristics and Their Petroleum Geological Significance of the Putaohua Reservoir in the North of the Changling Depression

Long-term oil and gas exploration indicates that the north of the Changling depression in the Songliao basin is the subsidence center in the Yaojia sedimentary period and considered to be a deep lake development zone of the Songliao basin. The analysis of drilling, logging, core, paleontology and so on shows that this area belongs to delta-front facies controlled by northern provenance,including the distributary channel and the superimposed sheet sand. Study of sedimentary characteristics of the Putaohua reservoir and planar distribution of sedimentary microfacies for various sand groups indicates superimposed sheet sandbodies in Xinli and Xinmin areas are of great importance to oil-gas exploration prospect.