川南地区嘉陵江组天然气气源研究

对川南地区下三叠统嘉陵江组烃源岩生烃条件、碳同位素特征、气源方向及运移通道作了分析研究，认为其自身生烃条件较差，气藏常规组分差异较大，高干燥系数与储量大小关系密切；烷烃类气体碳同位素特征分析证实该组气源与下伏上二叠统的烃源地层有关，混源特征明显；氩同位素特征表明该组气藏气源与二叠系具明显的亲缘关系；结合运移与聚集条件等分析确认该区嘉陵江组天然气主要来源于深层二叠系烃源层，储量大与混源密切相关；烃源岩内部断层是其主要运移通道。

RESEARCH ON THE GAS SOURCE OF JIALINGJIANG FORMATION IN SOUTH SICHUAN BASIN

The hydrocarbon generation conditions, carbon isotope characteristics, gas source direction and migration channels of Jialingjiang Formation source rocks in south Sichuan Basin are studied in this paper. It is considered that the hydrocarbon generation conditions are relatively poor; the common components are of bigger differences and the dryness coefficient is closely related to the reserves. It is verified by analyzing the carbon isotope characteristics of alkane gases that the gas source of the formation is relative to the source rocks of underlying Permian and is of obvious multi-source feature. Argon isotope characteristics indicate that the gas source is closely relative to Permian. It is determined by comprehensively analyzing the migration and gathering conditions that the natural gas, with a great reserve and being closely relative to multi-source, of Jialingjiang Formation in the area mainly originates from deep-seated Permian source rock. The hydrocarbon source faults are the main channels of gas migration.