Abstract: According to the actuality that there are much reservoir influential factors,complex relation between porosity and permeability,intensive anisotropism and difficulties to evaluate to carbonate rock reservoirs,T₁j² carbonate rock reservoir in Moxi Structure,centre Sichuan is taken as an example,gray fuzzy theory is used and some elements for reservoir evaluation,such as porosity,permeability,water saturation,expulsion pressure,average pore throat radius,effective thickness,and permeability variation coefficient,dash coefficient and range and so on are optimized.Because of the perplexing relation existing among these evaluation elements,grey association analysis is used to definite the weight coefficients of evaluation elements,and fuzzy comprehensive distinguish method is used to evaluate quality of carbonate rock reservoir,thereby the relation and"uncertainty"of elements for reservoir evaluation is resolved.Evaluation results are well consistent with the actual production of gas and oil,which proves that the method of carbonate rock reservoir evaluation based on grey fuzzy theory is workable.

Key words: grey fuzzy, carbonate rock, reservoir evaluation, T₁j² Gas Reservoir, Sichuan Basin, Moxi Structure