Reservoir characteristics and sensitivity analysis of upper Paleozoic He 8 member in Central Ordos Basin
The study area is adjacent to Sulige Gas field,but He 8 member,as the main gas producing in-terval,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 reser-voir,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 sensi-tivity.When the reservoir physical properties are poor,the sensitivity increases.
Ordos Basinsensitivityclay mineralsreservoir characteristicsHe 8 member