Abstract: Exetreme overbalanced perforation developed in 1990's is very suitable for wells in carbonate or hihgly heterogeneous or heavy damaged gas formations and has been widly and well applicated because of its dramatic and costeffective improvement in initial well productivity. In this paper, the principle and procedures of exetreme overbalanced perforation operations have been clearly addressed based on the analysis of technical characteristics. The wellbore performace equations have been derived according to energy conservation law and gasliquid interface moving feature to model the wellbore pressure performance and the method of solving this problem has been carried out accordingly, it is shown that the wellbore pressure performance results are quite reasonable which provides basic information for modeling of fracture propagation and productivity prediction. The effect of wellhead pressure and gas/liquid column height on wellbore pressure performance have also been analysed, thus let the optimization of EOP job design be available.

Key words: gas well, exetreme overbalanced perforation, well completion, modeling