鄂尔多斯盆地南部上古生界低孔低渗砂岩储层成岩作用特征研究  

Diagenetic Characteristics of the Lower Porosity and Permeability Sandstones of the Upper Paleozoic in the South of Ordos Basin

作　　者：闫建萍[1,2] 刘池洋[1] 张卫刚[3] 李彪[4] 

机构地区：[1]西北大学大陆动力学国家重点实验室、西北大学含油气盆地研究所,西安710069 [2]兰州大学资源环境学院,兰州730000 [3]长庆油田分公司长中石油勘探开发项目经理部,西安710021 [4]辽河石油勘探局长城钻探国内市场部,辽宁盘锦124010

出　　处：《地质学报》2010年第2期272-279,共8页Acta Geologica Sinica

基　　金：国家重点基础研究发展计划项目(编号2003CB214607);教育部长江学者和创新团队发展计划“能源盆地油气地质”项目(编号IRT0559)资助成果

摘　　要：对鄂尔多斯盆地南部山西组二段—下石盒子组八段储层砂岩的岩石学特征、孔隙类型与物性特征、胶结物种类及成岩作用特点的详细研究表明:山西组二段—下石盒子组八段砂岩的主要孔隙类型大部分是与胶结物和泥质杂基有关的微孔隙,也是造成研究区砂岩储层低孔低渗的内在原因之一。砂岩主要的成岩作用包括机械压实作用、胶结作用、溶蚀溶解作用。压实作用是成岩早期导致砂岩储层质量变差的主要原因之一;胶结作用包括硅质胶结、钙质胶结和粘土矿物胶结,硅质胶结对储层物性的贡献大于其他胶结类型,方解石是造成储层物性降低的主要胶结物;煤系地层埋藏后提供的酸性孔隙流体造成早期长石和方解石的溶蚀溶解,形成次生孔隙,对早期储层物性起到了一定的改善作用,但由于后期强烈的方解石胶结作用而消失殆尽。Detailed study on the rock property, pore types, measured porosity and permeability, cement and diagenesis of sandstones of the 2nd Member of Shanxi Formation to the 8th Member of Lower Shihezi Formation in the South of Ordos Basin indicates that the major pore types are micropores related to cement and clay mineral, which is the master factor leading to lower porosity and permeability. The main diagenesis types of sandstones are the mechanical compression, cementation and dissolution. Compression is one of the main factors that reduced the reservoir quality in early diagenetic stage. Cementation plays the most important role on the loss of porosity, especially the calcic cement,and the major cements include calcites, quartz overgrowths and clay minerals. The feldspar and calcite were dissolved by the organic acid liquids produced from the buried coal strata,which resulted in lots of secondary porosity in early diagenetic phase and contributed retention of reservoir quality of the sandstones, but the intense calcite cementation lately made the porosity loss.

关 键 词：鄂尔多斯盆地南部 山西组二段-下石盒子组八段 低孔低渗 成岩作用 

分 类 号：P618.13[天文地球—矿床学]