英吉苏凹陷石油地球化学特征及油源对比

总结了塔里木盆地英吉苏凹陷原油和主要烃源岩的地球化学特征,根据原油中轻烃、饱和烃生物标志物组成特征及碳同位素值,划分了原油的成因类型,进行了油-油对比和油-源对比。研究表明,华英参1井侏罗系碳质泥岩和煤的沉积环境介质盐度较低,且成熟度较低,未达到成熟门限。英南2井侏罗系原油处于低成熟阶段,主要来源于相对氧化、盐度较低的沉积环境中形成的烃源岩,即主要来源于中生界腐殖型烃源岩,具有混源的特征。龙口1井侏罗系原油则主要来源于盐度较高的缺氧还原性环境中形成的烃源岩,主要来源于寒武系-下奥陶统腐泥型烃源岩,华英参1井侏罗系和塔东2井寒武系原油与龙口1井的原油为同一油源,均处于成熟阶段。

The Geochemical Characteristics of Crude Oil and the Correlation of Oil Sources in Yingjisu Sag in Tarim Basin

The geochemical characteristics of crude oil and source rocks in Yinjisu sag are summarized. The genetic types of crude oil are classified, and the correlations between oil-oil and oil-source are conducted by applying light hydrocarbons, biomarkers, and carbon isotopes. The study shows that palaeosalinity of Jurassic carbonaceous mudstone and coal deposit of Jurassic in Huayingcan-1 Well are low in both palaeo-salinity and maturity, not reaching the mature threshold. Crude oil of Jurassic in Yingnan-2 Well is in stage of low maturity, mainly coming from low-salinity and oxidizing Mesozoic humic source rocks, with property of mixed sources. And oil of Jurassic in Longkou-1 Well is originated from hypersaline and anoxic reducing Cambrian-Lower Ordovician sapropelic source rocks. Oils of Jurassic in Huayingcan-1 Well, Cambrian in Tadong-2 Well and Jurassic in Longkou-1 Well are the same source in stage of thermal maturity.