摘要
鄂尔多斯盆地煤系页岩气储量巨大,主要赋存在盆地东缘的上古生界地层中。总结前人的研究成果,分析了该地区上古生界煤系泥页岩的空间分布特征(沉积环境和空间分布),有机地球化学特征(总有机碳含量、干酪根类型和有机质成熟度),储层物性特征(矿物种类及含量、孔隙度和渗透率、微裂缝发育情况)以及含气性特征等成藏条件。结果表明:鄂尔多斯盆地东缘上古生界页岩分布广泛,累计厚度>30 m,整体上TOC质量分数>2.0%,镜质组反射率为1.00%~2.25%,有机质类型以Ⅲ型为主、Ⅱ型次之,石英等脆性矿物含量高,属于低孔低渗储层,同时微裂缝较发育,这些地质条件有利于页岩气的形成与富集成藏。认为鄂尔多斯盆地东缘上古生界煤系页岩具有巨大的页岩气资源潜力,其中山西组的页岩气成藏潜力最大,在后期的地质研究中应予以重视。
With huge reserves, shale gas in coal measures in the Ordos Basin mainly exists in the Upper Paleozoic strata of the eastern margin of the basin. Built upon previous literature researches, this paper analyzed accumulation conditions of shale gas in the Upper Paleozoic coal measures of the study area, including its spatial distribution characteristics （ sedimentary environment and spatial distri- bution） ,organic geochemical characteristics （TOC content, kerogcn type and maturity of organic matter）, reservoir physical characteristics （mineral species and content, porosity, permeability and development of micro cracks）and gas-bearing properties and so on. The results show that the Upper Paleozoic shale gas in the eastern margin of the basin has a huge gas resources potential. It is widely distributed, with cumulative thickness greater than 30 m, TOC content over 2.0%, vitrinite refleetivity of 1,0% to 2.25%; Its main type of organic matter is type Ⅲ and type Ⅱ ; There is high content of quartz and other brittle minerals, low porosity and low permeability, well-developed microcracks. All of these conditions are beneficial to the formation and accumulation of shale gas. Shanxi Formation has the greatest potential for shale gas accumulation, which should be our priority in the later study of geology.
出处
《地质学刊》
CAS
2017年第1期54-61,共8页
Journal of Geology
基金
中国博士后科学基金项目(2015M571841)
煤层气资源与成藏教育部重点实验室开放基金项目(2016-003)
江苏高校优势学科建设工程资助项目
关键词
上古生界
煤系页岩气
成藏地质条件
鄂尔多斯盆地东缘
Upper Paleozoic
shale gas in coal measures
accumulation conditions
eastern margin of the Ordos Basin
