乌里雅斯太凹陷苏布构造带油气成藏特征与勘探方向

针对苏布地区油源条件、砂体沉积模式、有效储层展布以及成藏模式认识不清等问题,运用地球化学分析、精细砂体刻画、岩矿分析等多种手段,从生油岩、储层条件、储盖组合3个方面分析了该区的油气成藏条件,阐明了垂向上发育多个异常孔隙带的原因。研究表明:该区发育常规油藏横向构造聚集,有利砂体富集、非常规致密砂砾岩油气藏以及泥页岩油气藏3种成藏模式,纵向上中浅层为常规油藏,深层为非常规油气藏,呈现由浅至深为油藏带、油气混合带、气藏带分布规律。研究成果有效指导了该区勘探,可为乌里雅斯太凹陷南洼槽指明下步勘探方向。

Hydrocarbon Accumulation Characteristics and Exploration Targets of Subu Tectonic Belt in Ulyastai Sag

To address the problems of unknown oil source conditions, sandbody sedimentary patterns, effective reservoir distribution and reservoir formation patterns in Subu Area, various methods such as geochemical analysis, detailed sandbody characterization and rock-mineral analysis were employed to analyze the hydrocarbon accumulation conditions in this area from three aspects, including source rock, reservoir conditions, and facies reservoir-capping assemblage, and elucidate the reasons for the vertical development of multiple abnormal pore zones. The results of the study proved that there were three accumulation modes for reservoirs in this area, including "transverse tectonic aggregation and favorable sandbody accumulation" of conventional reservoir, unconventional "tight glutenite oil and gas reservoirs" and "shale oil and gas reservoirs", and the hydrocarbon reservoirs were middle-shallow conventional reservoir and deep unconventional reservoir longitudinally and distributed as oil reservoir belt, oil-gas mixed belt and gas reservoir belt from shallow to deep. The study results were effective in the guidance for exploration breakthroughs in the area, handover of reserves and further exploration targets of the southern subsag, Ulyastai Sag.