( 2 ) the most favorable region of gas formation lays inside of the shizhu synclinore and in the west of fangdou mountain block . the secondary favorable region is from zichuya region to longjuba region . the adverse region lays qiyue mountain structure including west of it and fangdou mountain structure 成藏的有利区位于石柱复向斜内和方西区块;成藏的较有利区位于茨竹垭? ?龙驹坝地区;成藏不利区位于齐岳山及其西翼、方斗山等地。