羌塘盆地中生界含油气系统特征

羌塘盆地位于青藏高原中北部,具有广泛的中生代海相沉积。羌塘盆地中生代具有发育良好、分布广泛的烃源岩,其中上三叠统的肖茶卡组、中侏罗统布曲组和夏里组有机质类型好,丰度高,成熟度高,埋藏较好,其生油量巨大,是盆地油气的主要来源之一。羌塘盆地储集层和盖层发育,储盖层性能优越。根据Magoon的含油气系统理论,把羌塘盆地含油气系统分为3套:肖茶卡组(T3x)、布曲组(J2 b)和索瓦组(J3s)含油气系统,其关键时刻主要有:a.侏罗纪末—早白垩世早期;b.新近纪沉积之后,生储盖时空配置好。 

Discussion on characteristics of Mesozoic petrolume system of Qiangtang basin in Tibet

Qiangtang basin locates in the north and mid potion of Qinghai-Tibet plateau,where widespread Mesozoic marine deposits. Mesozoic Qiangtang basin has high quality hydrocarbon source rocks. The thickness of source rocks is huge. The organic matter type of source rocks is perfect and its abundance is large. In the upper Triassic Xiaochaka Formation and the mid Jurrasic Buqu Formation and Xiali Formation the organic matter maturity varieties from mature to overmature. The burial conditions of source rocks is a relative perfect,and oil production is excitement large. The Mesozoic source rocks are one origin of oil and gas in Qiangtang basin. The characteristic of reservoir and cap rock is very superiority in Qiangtang basin. It is confirned that there are three petroleum systems of J3s、J2b and T3x in Qingtang basin by Magoon's petroleum system, and there are two key stages in Qiangtangbasin:later Jurassic-early Cretaceous and later Tertiary. The collocation of space-time is very nice.