西湖凹陷中央反转带中北部天然气高效成藏主控因素及富集规律

西湖凹陷中央反转带中北部大型气田成藏因素及动态匹配关系至今不明。通过针对烃源岩、储层、输导体系及成藏期等成藏关键因素进行系统分析，建立"源-储-圈-输"的动态成藏过程分析中央反转带中北部大气田的成藏主控因素。研究表明始新统宝石组与平湖组煤系烃源岩不仅生气强度大，而且中新世晚期以来的快速生、排气为中央反转带中北部的大中型天然气藏提供了充足油气源；花港组小于4 000 m地层的酸性地层水是形成有利储层的关键；中新世晚期发生的龙井运动强烈挤压作用使中央反转带发生了构造变形和断层开启活动，为圈闭和油气输导通道的形成创造了条件。综合"源-储-圈-输"分析认为成藏主控因素在生烃期的有机耦合造就了始新统煤系烃源岩高效生气及天然气的有效运移聚集成藏的全过程。本次研究为研究区大气田的勘探提供了借鉴。 

Major controlling factors and enrichment rules of highly efficient gas reservoiring in the north-central part of the central inversion belt,Xihu Depression

The main controlling factors of reservoir formation and dynamic matching relationship of large gas fields in the north-central part of the central inversion belt, Xihu Depression are still unknown. Based on the systematic analysis of the key reservoir forming factors such as source rock, reservoir, transportation system and reservoir forming period, this paper establishes the dynamic reservoir forming process of "source-reservoir-Circle-Transportation" to analyze the main reservoir forming factors of the large gas field in the north of China. The results show that the source rocks of the coal measures of Baoshi Formation and Pinghu Formation in Eocene not only have a strong accumulation of gas, but also have provided sufficient oil and gas sources for the large and medium-sized natural gas reservoirs in the north-central part of the central inversion belt since the Late Miocene. The acid formation water is the key to affect the physical properties of the reservoirs. The strong compression of Longjing movement in the Late Miocene resulted in structural deformation and faults in the central inversion belt. And opening activities created conditions for the formation of traps and oil-gas transport channels. Based on the analysis of "Source-Reservoir-Circle-Transportation", we suggest that the organic coupling between the main factors of reservoir formation and hydrocarbon generation period results in the whole process of efficient gas generation of source rock and effective migration and accumulation of natural gas in Eocene coal series. The research results provide reference for the exploration of atmospheric field in the study area.