通南巴地区下三叠统硫化氢成因及分布

位于四川盆地东北部通南巴构造带上的河坝1井在下三叠统测试获得工业气流，但气样分析中发现了一定浓度的硫化氢，目前还未见到该区硫化氢成因的相关研究成果及报道。为此，对该区下三叠统硫化氢成因及分布进行了研究。通过总结归纳自然界中硫化氢的各种生成机理和特点，对比邻区高含硫化氢气藏的储层特征，认为通南巴地区气藏中的硫化氢由硫酸盐热化学还原作用（TSR）所产生。以此为硫化氢分布预测的依据和前提，进而预测该区下三叠统嘉陵江组三段、嘉一段和飞仙关组三段基本不含硫化氢；嘉二段和飞四段具备硫化氢生成的条件，特别是嘉二段在测试及试采中均发现了一定浓度的硫化氢，但飞四段硫化氢含量有限。

GENESIS AND DISTRIBUTION OF H2S IN LOWER TRIASSIC IN TONGNANBA AREA, NORTHEAST SICHUAN BASIN

Industrial gas flow has been tested in the well Heba-1 located in Tongnanba structure in the northeastern Sichuan basin.Hydrogen sulfide(H2S) of a certain concentration was tested in the gas samples,but no relevant research results have been reported at present.For this reason,study is performed on the genesis and distribution of H2S in the Lower Triassic in the study area.Based on analyses of various genetic mechanisms and features of H2S in the nature and correlation with the characteristics of gas reservoirs with high concentration of H2S in the adjacent areas,it is believed that the H2S in the study area is generated through thermochemical sulfate reduction(TSR).This understanding is the basis of prediction of H2S distribution.It is predicted that there is basically no H2S occur in the reservoirs in the third and first members of Jialingjiang formation and the third member of Feixianguan formation.Conditions for H2S generation exist in the second member of Jialingjiang formation and the fourth member of Feixianguan formation,especially the former in which H2S of a certain concentration has been tested both in formation test and production test.However,the concentration of H2S in the latter is limited.