【摘要】 中亚地区阿姆河盆地盐下侏罗系碳酸盐岩发现大型—巨型天然气藏，天然气中硫化氢（H2S）含量高，天然气分布规律十分复杂。为了进一步提高该区高含硫气藏勘探开发效益，综合研究了高含硫气藏地质特征、时空分布、天然气组分特征，分析了高含硫天然气藏类型和成因，总结了高含硫天然气富集规律。研究结果表明：(1)盆地内H2S含量与上侏罗统硬石膏沉积和成岩有密切关系，高含硫气藏根据天然气中H2S来源可分为原地生成、异地生成和混合生成3类，其中以原地生成高含硫天然气藏为主，规模最大；(2)原地生成高含硫天然气藏可细分为台内—台缘相带石膏—石灰岩互层型、台缘斜坡相带高能礁滩型和台缘斜坡—盆地相带断控型，异地生成高含硫气藏可分为横向运聚型和纵向运聚型；(3)生烃坳陷和碳酸盐岩沉积相带控制了高含硫天然气富集程度，其中碳酸盐岩台缘相带是最为富集区带，通源断层可以进一步促进高含硫天然气的成藏富集，生烃坳陷内具有大型古隆起背景的继承性构造是最有利的勘探目标。结论认为，通过高含硫天然气成因和富集规律的认识，指出应加强盆地生烃坳陷区盐下侏罗系具有基底古隆起区和大型断裂区高含硫碳酸盐岩气藏的勘探。更多还原

【Abstract】 Large and giant high-sulfur gas reservoirs have been discovered in the pre-salt Jurassic carbonate rocks of the Amu Darya Basin in Central Asia with high H2S contents in natural gas and quite complicated gas distribution. To further improve the exploration and development benefit of high-sulfur gas reservoirs in this area, this paper comprehensively studies the geological characteristics,spatiotemporal distribution and natural gas compositions of these high-sulfur gas reservoirs, analyzes the types and origins of high-sulfur gas reservoirs, and summarizes the enrichment patterns of high-sulfur gas. The following results are obtained. First, the H2S content in the Amu Darya Basin is closely related to the deposition and diagenesis of Upper Jurassic anhydrite. According to the source of H2S in natural gas, high-sulfur gas reservoirs can be divided into three types, i.e., in-situ generation, allochthonous generation and mixed generation,among which, in-situ generation is dominant. Second, the in-situ generated high-sulfur gas reservoirs can be subdivided into the gypsum interbedded with limestone gas reservoir in intraplatform–platform margin facies zones, the high-energy reef–shoal gas reservoir in platform marginal slope zones, and the fault controlled gas reservoir in platform marginal slope–basin facies zones. The allochthonous generated high-sulfur gas reservoirs can be subdivided into the lateral migration and accumulation gas reservoir and the vertical migration and accumulation gas reservoir. Third, the enrichment degree of high-sulfur gas is controlled by hydrocarbon generating depressions and carbonate sedimentary facies zones, and the highest enrichment degree occurs in the carbonate platform margin facies zones. The faults connecting source rocks can further promote the accumulation and enrichment of high-sulfur gas, and inherited structures with large paleouplift background in the hydrocarbon generating depressions are the most favorable exploration targets. It is concluded, by understanding the formation mechanisms and enrichment patterns of high-sulfur gas, that exploration shall focus on the pre-salt Jurassic high-sulfur carbonate gas reservoirs with basement paleo-uplifts and large fault zones in the hydrocarbon generating depressions of the Amu Darya Basin.更多还原