白马庙气田侏罗系天然气地化特征  

GEOCHEMICAL CHARACTERISTICS OF NATURAL GAS IN JURASSIC IN BAIMAMIAO GAS FIELD IN WEST SICHUAN BASIN

作　　者：王顺玉[1] 戴鸿鸣[1] 王海清[1] 蔡开平[2] 杨跃明[2] 王应容[2] 

机构地区：[1]西南石油学院 [2]中国石油西南油气田分公司川西北气矿

出　　处：《天然气工业》2004年第3期12-15,共4页Natural Gas Industry

基　　金：CNPC中青年创新基金项目"天然气C4-C7烃类指纹变化规律研究"部分成果

摘　　要：川西地区白马庙气田侏罗系的天然气 ,以往大都认为是来自上三叠统煤系地层 ,但对具体来源于上三叠统哪一个层位却存在较大的分歧。有的认为是须二段气藏破坏后形成的次生气藏 ,有的则认为是来自须五段地层。根据天然气组成、碳同位素、凝析油 (天然气浓缩烃 )轻烃和储集层沥青的生物标志化合物分布特征的综合研究 ,表明白马庙气田侏罗系气藏的天然气主要是上三叠统煤系地层中不同烃源层生成天然气的混合产物 ,其中以须二段气藏气为主。天然气组成甲烷含量高 ,干燥系数大 ,碳同位素组成重 ,储层抽提物的甾烷成熟度参数都表明侏罗系的天然气成熟度较高 ,是高成熟阶段的产物 ,具晚期运移和聚集成藏的特征。从区域地质背景上看 。Most of people considered that the natural gas in Jurassic in Baimamiao gas field in West Sichuan Basin came from the coal measure strata of Upper Triassic in the past. However, there exist relatively large differences of concretely coming from which horizon in Upper Triassic. Some ones regarded it as a secondary gas reservoir formed after the T3x2 gas reservoir's being destroyed and the others thought of it came from T 3x5 (the fifth member of Xujiahe Formation, Upper Triassic). In light of the comprehensive research on the distribution characteristics of the gas composition, carbon isotope, condensate, light hydrocarbons and the biomarkers of reservoir asphalt, it was shown that the natural gas in Jurassic reservoir in Baimamiao gas field is mainly a mixture being composed of the gases originated from different hydrocarbon source beds in the coal measure strata of Upper Triassic, in which the T3x 2 gas reservoir is in the majority. In accordance with the high methane content in natural gas composition, large dry coefficient and heavier carbon isotope and according to the sterane maturity parameter of reservoir extract, it was indicated that the natural gas was a product at high mature stage, being of relatively high maturity and of the characteristics of late migration and accumulation. In regard to the regional geological background, the fault Daxing 5 played an important role in the upward migration and accumulation of the natural gas.

关 键 词：白马庙气田 天然气 碳同位素 轻烃 储集层 沥青 气源 

分 类 号：P618.13[天文地球—矿床学]