Resources Evaluations and Favorable Area Optimization of the Tight Oil in Yangdachengzi Reservoirs of North Songliao Basin

The Yangdachengzi oil reservoir in the northern part of the Songliao Basin belongs to the middle and lower strata of the Lower Cretaceous Quansan Formation. In recent years, after continuous discoveries, proven reserves have been submitted, and no separate resource evaluation has been conducted for the Yangdachengzi oil reservoir in the past. In order to realize the potential of tight oil resources in the Yangdachengzi oil reservoir in the northern Songliao Basin, based on the study of geological characteristics and reservoir formation conditions, the evaluation area was graded according to reservoir properties and oil content parameters. According to the exploration degree of tight oil in the study area, the graded resource abundance analogy method and small pixel volume method were applied to comprehensively evaluate the geological resources of tight oil in the Yangdachengzi oil reservoir, ranging from 350 million to 400 million tons. Among them, Class I resources accounted for 62%, Class II resources accounted for 26%, and Class III resources accounted for 12%. The resources are mainly distributed in the Sanzhao Depression, Daqing Changyuan, and Chaoyanggou terrace, accounting for 67%, 10%, and 9% of the total resources of the Yangdachengzi oil reservoir, respectively. Research has shown that the areas around Toutai Zhaozhou, Yushulin, the western side of Changyuan, Chaoyanggou, and Yongle Shengping are favorable areas for exploring tight oil in the Yangdachengzi oil reservoir.