柴达木盆地西部扎哈泉地区油气成藏过程

摘要

扎哈泉地区为柴达木盆地西部典型的致密油勘探区.通过储层定量颗粒荧光、包裹体岩相学、显微测温等分析技术,结合埋藏史和热史,对油气动态演化过程进行分析.扎哈泉地区油藏原油属中等密度常规原油,但储层的QGF-E、TSF荧光光谱特征显示该区原油既有轻质-中质原油,又有重质原油存在.储层中主要发育两类烃包裹体,早期主要为黄色荧光油包裹体,晚期主要发育蓝绿-淡蓝色荧光油包裹体.通过测定伴生盐水包裹体均一温度及埋藏史和热史分析认为,扎哈泉地区主要经历了下油砂山组沉积末期(13 Ma)的原油充注和狮子沟组沉积早期(6 Ma)至今的原油充注以及油藏向上覆地层调整过程.%The Zhahaquan area is a typical tight-oil exploration area in the western Qaidam Basin .The dynamic evolution and accumulation of oil and gas is studied deeply by the analysis of reservoir quantitative grain fluores -cence ( QGF) , fluid inclusions petrography and micro-temperature measurement , and then combined with the buri-al and thermal history of this area .The crude oil in reservoirs of Zhahaquan area is medium-density conventional oil, while the results of QGF-E and TSF indicate that both light-medium density oil and heavy density oil are exis-ted in reservoir .Two types of hydrocarbon fluid inclusions are mainly developed in this area , earlier oil inclusions with yellow fluorescence and later oil inclusions with blue green-light blue fluorescence .Based on the analysis of the homogenization temperature of inclusions and the burial and thermal history , it is concluded that there are two stages of hydrocarbon charging , of which the first charging time was around 13 Ma, which corresponded to the end of the deposition of Lower Youshashan Formation , the second charging time was about 6 Ma, which corresponded to the early deposition of Shizigou Formation .