乌审召二叠统山1、盒8段成岩作用与孔隙演化

Diagenesis and Porosity Evolution of Shan-1 and He-8 Members in the Uxin Ju Region, Inner Mongolia

研究鄂尔多斯盆地乌审召地区上古生界主要含气层位上二叠统山1、盒8段储层成岩作用及孔隙演化认为,该区成岩演化阶段主要处于晚成岩的B期至C期,储层受压实作用和胶结作用影响,而重结晶作用及溶解作用在一定程度上了改善了储层的物性。该区东部和西部埋藏条件差异大,孔隙演化特征有较大区别;西部岩屑砂岩、岩屑石英砂岩、石英砂岩原始孔隙度均值为33.5%、34.2%和35.0%,经过早成岩A至晚成岩B-C期后,孔隙度均值为9.8%、10.5%和9.3%;东部岩屑砂岩、岩屑石英砂岩的原始孔隙度均值为34.2%和33.7%,演化至今分别为9.7%和9.4%。

Study of the diagenesis and pore evolution of the H-8 and Shan-1 reservoir of the Upper Paleozoic indicates that the main diagenesis in the Uxin Ju region, Ordos Basin experienced a diagenetic evolution from early diagenetic B phase to later diagenetic phase C period. The pore evolution between the east and the west are obviously different. The primary porosities of lithic sandstone, lithic quartz sandstone and quartz sandstone in the west are 33.5%, 34.2% and 35.0%, respectively. At present, their mean values are 9.8%, 10.5% and 9.3 %, respectively. The primary porosities of lithic sandstone and lithic quartz sandstone in the east are 34.3% and 33.6%, respectively. The present mean values are 9.8% and 9.3%, respectively.