Study on natural gas enrichment model of tight sandstone reservoirs in Xu2 section of Yingshan area
作者单位：Exploration and Development Research Institute of Daqing Oilfield Co Ltd
会议名称：《2023年中国地球科学联合学术年会》
会议日期：1000年
学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程]
关 键 词：xujiahe formation tight sandstone reservoirs Xu2 section enrichment model
摘 要：The prospect of tight gas exploration in the Xujiahe Formation in the Sichuan Basin is promising, but the lack of understanding of the gas-water relationship and the enrichment law is the limited bottleneck for the beneficial development of tight gas in the Xujiahe Formation. Comprehensively utilizing the data from well logging and experiments in the Yingshan area, based on the theory of high-resolution sequence stratigraphy, we re-conceptualize the mechanism of tight gas formation in the Yingshan tectonics. The results show that through the identification of different levels of stratigraphic interfaces and lake flooding surfaces, the tight sandstone reservoirs of the Xu2 section in the Yingshan area can be categorized into one long term datum cyclone, and another six medium term datum cyclones, from bottom to top, as MSCl-MSC6. Among them, MSCl-MSC4 lithological assemblage pattern is regressive-accumulative, and MSC5-MSC6 develops intrusive-accumulative lithological assemblage. The rock combination and compositional characteristics of the ascending gyratory rocks have better compressive resistance, better physical conditions, and after tectonic adjustment, the gas-water dissimilarity is complete, and tectonic oil reservoirs are developed. The downward spiral sandstone reservoir of Xujiahe in Yingshan area has experienced relatively strong mechanical compaction, which seriously damaged the primary porosity of the reservoir, resulting in serious tightening of the tight sandstone reservoir in the work area, and the period of oil and gas injection into the reservoir is coupled with the tightening evolution of the reservoir. It has the characteristics of tightening-while-forming, which makes the descending cyclone as a whole gas-bearing and enriched in scale, and it is a favorable target for the future reserve upgrade of the Xu2 section of the Yingshan tectonics of the Xujiahe Formation. The aim is to provide an important reference and basis for the exploration of tight