Grading evaluation and prediction of fracture-cavity reservoirs in Cambrian Longwangmiao Formation of Moxi area, Sichuan Basin, SW China

WANG Bei,LIU Xiangjun,SIMA Liqiang

Table 1 Grading evaluation of pore throat structure in gas reservoir of Longwangmiao Formation.

Reservoir space grade Reservoir type Porosity/ % Displacement pressure/MPa Median pressure/MPa Median throat radius/μm Maximum throat radius/μm Maximum mercury injection/% Ejection efficency/% Grade I 1 >7 <0.2 <1 >0.7 >4.0 >90 >25 Grade II 2 4-7 0.2-0.9 1-5 0.2-0.7 0.8-4.0 85-90 15-25 Grade III 3 2-4 0.9-7.0 5-40 0.02-0.20 0.1-0.8 75-85 10-15 Grade IV 4 <2 >7.0 >40 <0.02 <0.1 <75 <10