ABSTRACT: A history of multiple periods of petroleum migration and accumulation in the Tazhong uplift, Tarim Basin
Wang, Feiyu1, Shuichang Zhang2, Digang Liang3 (1) Petroleum University of China, Beijing, China (2) RIPED,CNPC, Beijing, China (3) RIPED,CNPC, Beijing
Tazhong uplift is one of the most important regions of pay in the Tarim basin. It presents the typical petroleum accumulation pay in the polyhistory superimposed basin of China. Tazhong oil fields consist of three reservoirs: Ordovician carbonate, Silurian sandstone, upper Devonian to Carboniferous sandstone and carbonate respectively. According to the fossil record of petroleum migration and accumulation, reservoirs in the Tazhong uplift experienced a complicated hydrocarbon accumulation history. The first hydrocarbon migration and accumulation occurred in Silurian sandstone and Ordovician carbonate during the late Silurian to the early Devonian. Afterwards oil in Silurian sandstone reservoirs experienced alteration because of tilting, represented in the gigantic Silurian tar sandstone and residual reservoir. The second hydrocarbon migration and accumulation happened in Permian time, corresponding to an early Permian thermal event originating from volcanism. Hydrocarbon from high maturity Cambrian source rock mainly filled upper Devonian to Carboniferous sandstone and carbonate reservoirs. The third filling happened in the Cretaceous to Tertiary. Oil was generated from upper Ordovician carbonate mud mound source rocks, gas was generated from overmature Cambrian source rocks. Most of reservoirs experienced refilling, alteration and remigration, but the last period of petroleum migration and accumulation controlled the current distribution of commercial oil populations within the Tazhong uplift.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia