吉木萨尔凹陷斜坡区存在一个稠油环带,稠油的常规物性具有密度高、粘度高、初馏点高和凝固点降低、含蜡量降低的特点,属于普通稠油。稠油最显著的特点就是成熟度低,γ胡萝卜烷、β胡萝卜烷保存完好,以规则甾烷为主,三环萜烷含量低,藿烷含量变化大。成熟度较低的重质油易成为稠油,地质综合因素控制稠油的分布;在原油稠化的诸多因素中,生物降解是最主要的因素。稠油属于近距离成藏,油源位于凹陷深部。油气有2期成藏,稠油是由第一期成藏的低成熟原油经生物降解稠变而成。 There is a heavy oil zone in the slopes of Jimsar Sag. The heavy oil has the characteristics of high density, high viscosity, high initial boiling point, low freezing point and low wax content, belonging to common heavy oil. The most prominent feature of heavy oil is low maturity, γ carrot alkane, β carotenoid preserved intact, regular sterane, tricyclic terpane content is low, hopane content changes. The heavy oil with low maturity is easy to become heavy oil, and the comprehensive geological factors control the distribution of heavy oil. Among the many factors of crude oil thickening, biodegradation is the most important factor. Heavy oil belongs to close reservoir formation, oil source is located in the deep depression. There are two stages of hydrocarbon accumulation, heavy oil is formed by the first phase of low-mature crude oil biodegraded by thickening.