Reservoir classification and evaluation of He 8 and Shan 1 members in the east of Sulige gasfield

He 8 and Shan 1 members in the east of Sulige gasfield had characteristics of high reservoir heterogeneity,obvious physical property distinctions,and the distribution understanding of different reservoirs was not clear.With consideration of sandstone thickness,net-to-gross ratio,porosity and permeability,fuzzy clustering method was applied to carry out reservoir classification and evaluation.The reservoirs were classified into 3 categories.Type-Ⅰ accounted for 16.3% of all reservoirs,with sandstone thickness of 11.4m,net-to-gross ratio of 0.65,porosity of 8.5% and permeability of 0.7×10~(-3)μm~2.Type-Ⅱ accounted for 27.9%,with sandstone thickness of 9.1m,net-to-gross ratio of 0.55,porosity of 6.9%and permeability of 0.32×10~(-3)μm~2.Type-Ⅲaccounted for 55.8%,with sandstone thickness of 5.9m,net-to-gross ratio of 0.39,porosity of 5.2%,permeability of 0.14×10~(-3)μm~2.Among these reservoirs,type-Ⅰ and type-Ⅱ presented lentoid and beltlike distribution,which was good for gas and oil enrichment and could be taken as the target for subsequent development.