鄂尔多斯盆地中部上古生界盒8段储层特征及敏感性分析

Reservoir characteristics and sensitivity analysis of upper Paleozoic He 8 member in Central Ordos Basin

研究区紧邻苏里格气田,但是作为苏里格气田主要产气层段的盒8段在研究区产气较差,为究其原因,针对上古生界盒8段储层应用X衍射、全岩定量分析、薄片鉴定、水驱敏感性流动实验等方法开展储层特征和敏感性研究,明确其影响因素,为下一步增产开发提供思路。实验结果表明,研究区目的层段以石英岩屑砂岩为主,为低-特低孔、特低渗储层。孔隙分选较差,以小孔喉为主;储层具有弱-中等偏弱速敏、强-中等偏强水敏、弱酸敏、中等偏弱盐敏、弱碱敏等特点。研究区伊蒙混层、伊利石和高岭石对储层的水敏、速敏和盐敏具有控制作用,此外储层物性于敏感性也存在一定的相关性,储层物性差时,敏感性增强。

The study area is adjacent to Sulige Gas field,but He 8 member,as the main gas producing interval,has poor gas production.In order to find out why,using methods such as X-ray diffraction,whole rock quantitative analysis,thin section identification,and water drive sensitivity flow experiments to study the reservoir characteristics and sensitivity of the upper Paleozoic He 8,clarifying its influencing factors,and providing ideas for the next step of stimulation and development.The test results show that the target member is mainly quartz lithic sandstone,which is an ultra-low porosity and ultra-low permeability reservoir,with poor pore sorting,mainly with small pore throats.The reservoir has characteristics such as weak to medium to weak velocity sensitivity,strong to medium to strong water sensitivity,weak acid sensitivity,medium to weak salt sensitivity,and weak alkali sensitivity.The Yimeng mixed layer,illite,and kaolinite in the study area have a controlling effect on the water sensitivity,velocity sensitivity,and salt sensitivity of the reservoir.In addition,there is a certain correlation between the reservoir physical properties and sensitivity.When the reservoir physical properties are poor,the sensitivity increases.