Abstract: In view of the heavy difficulties in prediction of key development indicators of fractured-cavity carbonate reservoirs, a prediction method was established for the key development indicators from isolated fracture-cavity reservoirs to the whole block on the basis of the theories of material balance, well-controlled dynamic reserves evaluation, and regression analysis of the dynamic and static parameters of the reservoir bodies in production. With the aid of this method, relatively accurate predication results were obtained for key development indicators of single well, even the whole block, including available reserves, recoverable reserves, recovery efficiency, and gas lift measures for oil enhancement. This method applied to the Zhonggu I Block, and the results indicated that the recoverable oil and gas reserves of the block were 85.8×10⁴m³ and 26.6×10⁸m³ respectively, and the oil and gas (decreasing) recovery rates were 27.8% and 59.2% respectively, the recoverable reserves of remaining reservoir bodies not put in production in the block are 36.4×10⁸m³, the oil and gas recovery rates after gas lift were 32.6% and 68.4% respectively, increased by 4.8、9.2 percentage points. This method can effectively predict the key development indicators of single-well reservoir bodies and blocks of such oil and gas reservoirs, providing a basis for the formulation of development plans and technical policies.

Key words: carbonate rock, fracture-cavity type, condensate gas reservoir, development indicators, produced reserves, recovery rate, Zhonggu I Block