中文摘要：

致密油气是世界上近20年来勘探、开发和研究的热点。在大量文献资料调研的基础上，首先总结了前人对致密储层特征及成因、致密储层油气形成和分布特征以及致密储层油气运移和聚集机理等方面的研究现状；然后分析了目前国内外有关致密储层油气成藏研究的主要特点；最后提出微米-纳米级孔喉网络系统油气充注、运移和聚集机理是致密储层油气成藏机理的核心科学问题，具体体现为油气由烃源岩向致密储层的充注机理、致密储层微米-纳米级孔喉网络系统油气运移的渗流机理以及致密储层微米-纳米级孔喉网络系统油气的赋存和聚集（滞留）机理3个具体的关键科学问题，而这将是致密储层油气成藏机理下一步研究的重点。

英文摘要：

Tight oil and tight gas have been a hot area of petroleum exploration, development and research for the past 20 years. Based on extensive research of literature, the study status of tight reservoir characteristics and geneses, petroleum formation and distribution characteristics in tight reservoirs, and petroleum migration and accu mulation mechanism in tight reservoirs are firstly summarized in this article. Secondly, the main features of domes tic and international tight oil and gas accumulation researches are analyzed. At last, the article point out that the key scientific issue of tight oil and gas pool formation is petroleum injection, migration and accumulation in micro nano pore network systems, which refers to petroleum injection mechanism from source rocks to tight reservoirs, pe troleum migration and percolation mechanism in micronano pore network systems and petroleum occurrence and ac cumulation （detention） mechanism in micronano pore network systems. Investigation on tight reservoir oil and gas accumulation mechanism should pay attention to three key scientific problems.