松辽盆地汪升地区深层天然气地球化学特征及成因

Geochemical characteristics and origin of natural gas in Wang Sheng area, Songliao basin.

松辽盆地汪家屯—升平地区天然气化学组分和碳同位素特征的综合分析表明，该区天然气的成因类型有油型气、煤型气和混合气，但单一型的天然气很少，以混合气为主。混合气是由同一源岩中不同有机质生成的天然气混合造成的，以原生混合气为主。纵向上，天然气中重烃气在下部地层含量高，向上逐渐减少；具有甲烷碳同位素值变化大、组分碳同位素倒转系列常见而正碳同位素系列较少见的碳同位素分布特征。非烃气体的分布，纵向上以登娄库组以下的营城组火山岩系含量最高，平面上高含量非烃气体的分布常与深大断裂的走向相一致，可能主要为无机成因。

Based on analysis on chemical composition and carbon isotopes of natural gas, 3 genetic types of gas can be identified, including oil type gas, coal formed gas and mixture gas in Wang Sheng area. Mixture gas is mainly generated by different organic matter in the same source rock. Amount of heavy hydrocarbon gases is higher in lower formation than in upper formation; Carbon isotope of methane changed dramatically, and carbon isotope series of CH 4 C 2H 6 C 3H 8 C 4H 10 is characterized by reverse. The distribution of high content inorganic gases is often associated with deep fault.