College of Geoscience and Surveying Engineering,China University of Mining and Technology(Beijing),Beijing ,China

海陆过渡相煤系砂岩中赋存丰富的天然气资源,为了进行煤系致密砂岩有利区块的优选,通过铸体薄片、扫描电镜、X衍射和孔渗测试等测试手段,研究了临县地区太原组致密砂岩的储层特征、成岩作用特征及其对储层的影响。研究结果表明:储层岩性以岩屑石英砂岩为主,处于中成岩作用B阶段;孔隙类型以残余粒间孔、粒间溶孔、粒内溶孔和黏土矿物晶间孔为主;压实作用是造成储层低孔低渗的主要因素;储层中黏土矿物含量较高,发育高岭石、伊利石、绿泥石和伊/蒙混层,其中高岭石多由长石和岩屑蚀变生成,与储层物性具有一定的正相关性;煤系有机质丰富,有机酸的生成一方面会增加孔隙溶蚀,但也为石英等矿物的自生长提供了空间和物质来源。

Abundant unconventional gas resources were stored in tight sandstone reservoir,which deposited in marine-continental transitional coal measures.In order to make great breakthrough in tight sandstone gas in coal measures,the characteristics of tight sandstone reservoirs in coal measure in Linxian area were analyzed and the diagenetic process and its impacts on reservoir properties were also discussed,which were based on thin sections,scanning electron microscope,X-ray diffraction,porosity and permeability test,which will make great .The results show that the sandstonesare mostly sublithareniteandhas entered the middle diagenetic Stage B.The types of pores are dominated byresidual intergranular pore,intergranular dissolution pores,intragranular dissolved pores and kaolinite intercrystallinepores.The content of clay minerals in sandstones is high,including kaolinite,illite,chlorite and mix-layerillite/smectite.And the kaolinite contents have a positive relationship with porosity and permeability,indicating that the existence of kaolinite have a positive influence on reservoir qualities.Compaction play a leading role in reducing reservoir porosity and permeability.There exist abundant organic matters in coal measure,which resulted in organic acid formed in diagenetic process.the organic acid not only promote the dissolution,but also provided material andthe room for authigenic quartz growing.

中国地质调查局地质调查资助项目(1211302108025-4)；国家自然科学基金资助项目(41572141,41702171)；