四川盆地二叠系烃源岩分布特征

Distribution Characteristics of Permian Source Rocks in Sichuan Basin

二叠系-中下三叠统是四川盆地天然气勘探的主要目的层系,已发现的许多大中型气田的天然气都来源于二叠系烃源岩。二叠系沉积建造为下统-阳新统和上统-乐平统,下统-阳新统由下而上可三分为梁山组(P1l)、栖霞组(P1q)和茅口组(P1m);上统-乐平统由下而上可分为龙潭组(P2l)和长兴-大隆组(P2ch)。二叠系主要烃源层可分为油系烃源岩层和煤系烃源岩层。二叠系上统长兴组,下统茅口组、栖霞组是四川盆地主要产层。

Permian-Middle-Lower Triassic is the main target strata for natural gas exploration in Sichuan Basin.Many large and mediumsized gas fields have been found that the natural gas comes from Permian source rock.The Permian sedimentary formation is composed of lower Yangxin Series and upper Leping series.The lower Yangxin Series can be divided into Liangshan formation(P1l),Qixia Formation(P1q)and Maokou Formation(P1m)from the bottom up.And the upper Leping series can be divided into Longtan Formation(P2l)and Changxing Dalong formation(P2ch)from the bottom up.The main source rocks of Permian can be divided into oil series source rocks and coal series source rocks.Changxing Formation of Upper Permian,Maokou Formation and Qixia Formation of Lower Permian are the main productive strata in Sichuan Basin.