川东石炭系中的天然气属于油型气,初为原油,曾经聚集于印支运动中形成的梁平—长寿古隆起带里,形成油藏。经过燕山及喜山运动,川东狭长形的背斜带,取代了古隆起带,油藏中的原油被裂解成天然气,同时发生再次运移,而在新形成的背斜带中聚集成气藏。此时志留系烃源岩进入过成熟阶段生成的干气,又混入气藏之中,发生了碳同位素倒转(δ~(13)C_1>δ~(13)C_2)的现象。 The natural gas in the Carboniferous of eastern Sichuan belongs to the oil type gas and was originally crude oil. It was once accumulated in the Liangping-Changshou paleo-uplift zone formed during the Indosinian movement and formed a reservoir. After the Yanshan and Himalayan movements, the long and narrow anticline in eastern Sichuan replaced the paleo-uplift, and the crude oil in the reservoir was cracked into natural gas and re-migrated at the same time, forming gas in the newly formed anticline Tibetan. At this time, the Silurian source rocks entered the dry gas generated during the overripe stage and mixed with gas reservoirs, resulting in the phenomenon of carbon isotope inversion (δ ~ (13) C_1> δ ~ (13) C_2).