Study on sedimentary micro facies of the Chang2 reservoir in Zhangjiawan

Chang2 reservoir in Zhangjiawan area development degree is high,but research has not been done deeply,the oil and gas accumulation is complex,it is difficult to develop.Based on the outcrop observation,core description and logging data analysis,the characteristics of sedimentary micro facies and the distribution of micro facies in each layer of Chang2 reservoir in Zhangjiawan area are systematically studied.The results show that Chang2 reservoir in Zhangjiawan area is mainly composed of gray fine- sandstone.Delta plain subfacies deposition are the main deposits in Chang2 reservoir in Zhangjiawan area.Mainly includes four micro facies, which are the underwater distributary channel,natural levee,crevasse splay and flood plain facies.The controlling role of sedimentary micro facies to layer physical property and hydrocarbon enrichment is obvious.The underwater distributary channel is Chang2 formation's frame micro facies,which is the most advantageous oil gas enrichment zone.Chang22 is the main oil-bearing.