塔里木盆地优质气源岩特征

塔里木盆地优质气源岩(有机碳含量大于等于0．5％)主要赋存于寒武一奥陶系、石炭一二叠系、三叠一件罗系三大层系中,它们具有不同的平面分布规律和不同的岩石学、沉积学、有机地球化学特征。据现今的生烃产物类型评价,则包括了仅能生气的气源岩与既能生油、又能生气的油一气源岩两大类型,从而区别于四川盆地和鄂尔多斯盆地。研究结果表明,特定构造背景下的特殊沉积环境与源岩的有机质类型及其热演化程度三大因素决定气源岩的发育与否及其质量优劣。

Characteristics of Premium Gas Source Rocks in Tarim Basin

The premium gas source rocks with content of organic carbon equal to or higher than 0.5%in Tarim basin are mostly found in Cambrian--Ordovician, Carboniferous-Permian and Triassic --Jurassic systems which have different horizontal distributions and various characteristics in lithology, sedimentology andorganic geochemistry. It is indicated by present evaluation of hydrocarbon source types that there are twotypes of the products in Tarim basin, i.e. gas source rock where gas is only generated, and oil-gas sourcerock where both oil and gas are generated, being different from those of Sichuan basin and Erdos basin.The result shows that it is the three major factors, such as special sedimentary environment under specialstrUctural setting, types of organic matter in source rocks and degrees of thermal evolution, that controlwhether gas source rock developed or not and quality of it.