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川东地区三叠系飞仙关组是一套区域性含气层，目前已成为继石炭系后的重要天然气勘探接替层。该含气层完全有别于其它二叠系、三叠系及石炭系气藏，依硫化氢含量可分为低含硫气藏、中含硫气藏、高－特高含硫气藏。分布上从南到北可分为硫化氢含量两高两低的4个区，即渡口河等构造为代表的高含硫北区和龙门等构造高含硫南区；铁山、雷沙罐坪等构造低含硫北区和新市等构造低含硫南区。其硫化氢分布规律与区域沉积相有着 良好的对应关系。该区气藏高含硫的原因以矿物成因为主，高含硫分布与含石膏地层分布是基本一致的。

Characteristics of Hydrogen Sulfide Distribution in Feixianguan Formation Gas Reservoir in East Sichuan

??The Feixianguan Formation of Triassic in East Sichuan is a series of regional gas-bearing strata and has become an important natural gas exploration replacement strata following after Carboniferous at present.The gas-bearing strata being obviously different from the reservoirs in Triassic,Permian and Carboniferous may be divided into low sulfur-bearing gas reservoirs,medium sulfur-bearing gas reservoirs and high??super sulfur-bearing gas reservoirs according to hydrogen sulfide content.Two high and two low sulfur-bearing regions have been discovered from south to north,i.e.the north high sulfur-bearing region represented by Dukouhe structure,etc.,and the south high sulfur-bearing region represented by Longmen structure,etc.;and the north low sulfur-bearing region represented by Tieshan and Leishaguanping structures etc.,and the south low sulfur-bearing region represented by Xinshi structure,etc.A fair correspondence relation between hydrogen sulfide distribution and sedimentary facies has been found,i.e.the high sulfur-bearing distribution area is identical to the gypseous layer distribution area,therefore the high sulfur content in the gas reservoirs in East Sichuan mainly results from mineral genesis.