Abstract: In order to implement the proved reserves and remaining undeveloped reserves of strong heterogeneous tight sandstone gas reservoirs in Sulige gas field and evaluate the potential of steady production, based on geological knowledge database,the reservoir was divided into several calculation units both in plane and in vertical,and the reserves of the units was also recalculated separately with volumetric method. Reserves classification and evaluation criteria were established based on reservoir static parameters,gas well production index and internal rate of return. According to the evaluation criteria,the reserves can be divided into three types:enriched area,dense area and water-rich area. And the used and remaining unused reserves were evaluated by the "single well controlled area method". The evaluation results show that there is a great difference in the degree of developed reserves among different blocks in Sulige gas field,overall the comprehensive utilization degree of reserves is 40.1%. The remaining undeveloped reserves are large in scale and have good potential for stable production. Under the current economic and technological conditions,improving reserves utilization in enriched and dense areas by through well pattern infilling,sidetracking horizontal wells and re-perforation modification of gas well are main realistic ways to stable production of gas field. Effective utilization of remaining reserves in water-rich areas still needs to be tackled further.

Key words: reserves recalculating, remaining undeveloped reserves, classified evaluation, tight sandstone gas, Sulige gas field