白音查干凹陷油气富集规律

Hydrocarbon Accumulation in Baiyinchagan Sag,Erlian Basin

白音查干凹陷是一个北断南超的箕状断陷湖盆 ,其主要生油、储油层系为下白垩统 ,主要发育冲积扇及扇三角洲沉积。油气以向南部斜坡带的侧向运移为主 ,构造背景及砂体分布规律控制油气富集 ,南斜坡带是油气主要聚集区。该区主要发育自生自储油藏和下生上储油藏 ,且自生自储油藏优于下生上储油藏。勘探经验是下洼找稀油、近凹找富集。

The Baiyinchagan sag is a half graben basin with a fault in the northern side and an overlap in the southern side, where the main oil source and reservoir is lower Cretaceous series. The main depositional systems in the sag are alluvial fan and fan delta Lateral migration of oil and gas is toward the southern slop, the structural framework and the distribution of sandbodies control the accumulation of oil and gas The southern slop is a main hydrocarbon accumulation area in the sag In the area, two types of pools are common, one results from generating and preserving hydrocarbon in the same formation,the other from generating in lower formation and preserving in upper one. The former is better than the latter The exploration experience shows that light oil occurs in the lower part of the depression, bonanza pools near the depression and viscous oil in the shallow formation of the slop belt