Limits and grading evaluation criteria of tight oil reservoirs in typical continental basins of China

ZHOU Nengwu,LU Shuangfang,WANG Min,HUANG Wenbiao,XIAO Dianshi,JIAO Chenxue,WANG Jingming,TIAN Weichao,ZHOU Lei,CHEN Fangwen,LIU Wei,WANG Zhixuan

Table 2 Upper limits of the physical properties of tight oil reservoirs in typical continental basins in China.

Basin Geological age Formation Rock type Surface tension/ (N·m-1) Wetting angle/(°) Stratigraphic dip/(°) Pore- throat ratio Difference between ρw and ρo/(g·cm-3) r/μm Porosity/ % Permea- bility/ 10-3 μm2 Songliao Lower Cretaceous Quantou Formation Medium fine sand 0.014 5 25 10.0 90 0.25 0.80 12 1.0 Songliao Upper Cretaceous Qingshankou Formation Fine silt 0.014 5 40 3.1 150 0.14 0.60 12 1.3 Bohai Bay Paleogene Kongdian- Shahejie Formation Glutenite 0.001 5 27 12.0 200 0.14 1.50 11 1.0 North Jiangsu Paleogene Funing Formation Siltstone 0.001 5 23 15.0 180 0.14 2.16 12 1.0