摘要
There are different views on the genetic type of natural gas and gas source in Jurassic of the central Sichuan Basin.This paper uses three characteristics of the natural gas,that is,the characteristics of component,carbon isotope and light hydrocarbon,to recognize these problems again.An analysis of the components shows that the natural gas in Jurassic is mainly oil-type gas from kerogen cracking;Carbon isotope analysis indicates that the natural gas in Jurassic is mainly oil-type gas,but a part of it is coal-related gas.The light hydrocarbon analysis shows that the natural gas in Jurassic is mainly oil-type gas.Based on these results,it can be concluded that the natural gas in Jurassic of the central Sichuan Basin is mainly oil-type gas from kerogen cracking and only a small amount of it is coal-related gas.The oil-type gas in Jurassic reservoir derives from the Jurassic source rocks,but the coal-related gas derives from the upper Triassic source rocks.