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 3 Grading table of tight oil reservoirs in typical continental basins in China.

Reservoir type Comprehensive boundary Songliao Basin Qingshankou Formation Songliao Basin Quantou Formation Junggar Basin Lucaogou Formation Junggar Basin Baikouquan Formation Bohai Bay Basin Kongdian-Shahejie Formation North Jiangsu Basin Funing Formation Reservoir boundary Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Poro- sity/% Perme- ability/ 10-3 μm2 Conventional >12 >1.00 >12 >1.300 >1.000 >0.60 >11.00 >1.000 >12.50 >1.130 Upper limit of physical property Type I >9 >0.50 >10 >0.700 >12.0 >0.600 >12 >0.060 >9 >0.20 >8.00 >0.500 >10.50 >0.500 Lower limit of effective seepage Type II >7 >0.10 >8 >0.200 >9.0 >0.200 >10 >0.022 >8 >0.10 >6.00 >0.120 >8.00 >0.120 Type III >5 >0.03 >5 >0.030 >4.0 >0.010 >8 >0.012 >7 >0.03 >3.50 >0.040 >6.50 >0.070 Lower limit of accumu- lation Type IV >3 >0.01 <5 <0.030 <4.0 <0.010 <8 <0.012 >5 >0.03 <3.50 <0.040 <6.50 <0.070 Non- reservoir <3 <0.01 <3 <0.012 <3.4 <0.015 <1 <0.000 12 <3.29 <0.031 <1.66 <0.024 Theoretical lower limit