【作者】 胡安平；

【导师】 戴金星； 黎茂稳； 陈汉林；

【作者基本信息】 浙江大学 ， 地质学， 2009， 博士

【摘要】 本文应用有机岩石学和有机地球化学研究手段,通过现场工作、实验分析以及国内外盆地类比,对川东北飞仙关组含硫化氢气藏储层TSR反应、天然气成因及气源等进行了研究,主要取得以下几个方面的认识:(1)根据川东北含硫化氢气藏储层固体沥青的镜下非均质性、沥青元素组成和沥青反射率的非均质性特征,发现川东北地区飞仙关组～长兴组储层TSR反应不充分,仅部分影响到沥青,还未波及气态烃类组分;(2)川东北飞仙关组气藏天然气成因多样化,普光气田存在多种成因天然气,即:Ⅲ型、Ⅱ型、后期改造的油裂解气,反映本区存在多套独立的天然气运聚系统;(3)川东及川东北地区普遍发生早期原油伴生气中甲烷优先散失,后期构造抬升导致部分水溶气逸出,这一过程使得气藏中乙烷碳同位素特别轻;(4)川东北飞仙关组气藏主要是以上二叠统龙潭组烃源岩的原油裂解气,同时有来自与储层同期沉积地层或下伏地层的滩前、滩后滞流相烃源岩以及深部烃源岩的共同贡献;(5)TSR反应所需要的物质是烃类和硫酸钙溶液,该地区硫酸钙溶液来源除了储层及周边地层水外,还有一个很重要的来源可能是深部热液来源,导致本区各个气藏TSR反应程度不同主要原因是硫酸钙溶液的供给不同。更多还原

【Abstract】 Based on field observation, laboratory experiments and geological analogy analysis, this study used organic petrography and organic geochemistry to constrain thermochemical sulfate reduction （TSR） and natural gas origin for the sour gas accumulations in the Lower Triassic Feixianguan Formation, northeastern Sichuan Basin. The presence of highly heterogeneous reservoir bitumens in terms of both bitumen reflectance and S/C and O/C atomic ratios indicates that the reservoir bitumens have only been partially affected by TSR reactions, but the chemical and stable carbon isotopic signatures of gaseous alkanes remain largely genetically indicative. The identification of multiple types of gases occurring in the Feixianguan Formation reservoirs implies several discrete gas migration and accumulation conduits. The preferential leakage of methane from the early accumulated oils, in combination of a later addition of soluble gases from the water leg during the late stage uplift, could help explain why the ethane in the eastern and northeaster Sichuan Basin is exceedingly enriched in ¹²C. Several lines of evidence suggest the Upper Permian Longtan Formation as the main source rocks for the paleo-oil accumulation in the Feixianguan Formation, and the sour gas accumulations resulted from thermal oil cracking and TSR reactions. Minor contributions also come from inter-reefal lagoonal source rocks within the Feixianguan Formation and deeper strata. In addition to formation waters within the gas reservoirs and/or cap rocks, hydrothermal fluids derived from deep seated basement faults may also provide both heat and sulfate for TSR reactions in some of the studied reservoirs. It appears that sulfate supply is the main rate limiting step for the TSR reactions.更多还原