美索不达米亚盆地成藏主控因素分析

美索不达米亚盆地是全球油气最富集的盆地之一,主要产层为白垩系.在构造、沉积、钻井、测试等资料基础之上,研究认为多套优质成熟烃源岩、有利的储盖组合、一系列大型背斜圈闭控制着盆地内大型油气田的形成.受成藏条件控制,盆地中—南部和北部发育2种不同的成藏模式.盆地中—南部发育下生上储型的生储盖组合,油气以通过输导层的水平运移为主,烃源岩差异造成原油性质的差异.盆地北部,侏罗系—下白垩统烃源岩生成的油气沿大型走滑断层运移到上白垩统储层,油气的差异运移聚集作用造成油气藏原油特征下轻上重.

Main controlling factors of hydrocarbon accumulation in Mesopotamia Basin

The Mesopotamia Basin is one of the most prolific petroliferous basins in the world.The most important productive layer is Cretaceous.Based on the comprehensive analyses of structure,sedimentary,drilling and testing,the paper summarizes the controlling factors of hydrocarbon accumulation.They are high-quality source rocks,good reservoir-seal assemblages,huge structural traps,migration pathways and so on.There are two kinds of accumulation models in the Mesopotamia Basin.In the center and south of the basin,petroleum gene-rates in the lower formation and is reserved in the upper formation.Carrier beds are the main pathways for oil-and-gas migrations in the parallel direction.The characteristics of petroleum are controlled by source rocks.In the north,oil and gas migrate from the Jurassic and the Lower Cretaceous source rocks to the Upper Cretaceous reservoirs along strike slip faults.The differential hydrocarbon accumulations lead to light oil in the lower formation and heavy oil in the upper formation.