关键词: 鄂托克旗地区, 　优质储层, 　控制因素, 　成岩作用, 　微裂缝

Abstract: The region of Etuokeqi is an important area for increasing reserves and improving productivity of Changqing oilfield, where the tight sandstone gas reservoir of He 8 and Shan 1 member of Upper Paleozoic is developed. In order to systematically study the controlling factors of high⁃quality reservoirs distribution, this paper applies rock thin slices, cast slices and other conventional analysis data to research controlling factors of high⁃quality reservoirs in the aspects of material sources, sedimentary features, diagenesis, hydrocarbon filling and microcrack development. The results show that, the supply environment of near source parent rock is abundant and quartz content is high, which provides material basis for the development of high⁃quality reservoir; the high porous⁃permeable reservoir formed in the main steam channel belt of delta plain, in which the point bar of braided⁃stream and meandering river is the advantageous sedimentary micro⁃facies; the compaction and cementation of reservoir are widespread, relatively the dissolution effectively improve physical property, so the weak cementation and strong dissolution zones are the major ones of high⁃quality reservoir; the filling of high saturate hydrocarbon promotes dissolution and restrains cementation in the high⁃quality reservoir; micro⁃fractures constitute the drainage system in reservoir and play an important role in reservoir pore expansion and natural gas migration and accumulation.

Key words: Etuokeqi area, High quality reservoir, Control factor, Diagenesis, Micro?fracture