鄂尔多斯盆地三叠系长8储集层致密与成藏耦合关系——来自地球化学和流体包裹体的证据

发布时间：2018-09-14 17:43

【摘要】：采用物理压碎、酸液处理与分步抽提相结合的方法,对储集层样品中不同赋存状态的烃类进行分离;再利用气相色谱-质谱联用仪进行组分分析,并结合包裹体均一温度、荧光光谱分析,研究了各类烃之间的关系及充注期次。结果表明,鄂尔多斯盆地三叠系延长组长8含油砂岩中存在4种不同赋存状态的烃类,即游离烃、封闭烃、碳酸盐胶结物包裹体烃以及长石与石英包裹体烃。其中,游离烃的含量在抽提物中占绝对优势,平均为93.4%。包裹体烃荧光光谱λ_(max)、QF_(535)和Q——(650/500)等参数对比分析表明,长石、石英、碳酸盐胶结物包裹体烃成熟度依次增大,其中长石和石英中包裹体烃的荧光光谱各项参数数值相近,而与碳酸盐包裹体烃差异较大。C_(29)ββ/(αα+ββ)与C_(29)20S/(20S+20R)值和甲基菲比值对比分析表明,长石与石英包裹体烃、碳酸盐胶结物包裹体烃、封闭烃、游离烃的热演化程度呈现依次增高的趋势,且游离烃与封闭烃的热演化程度相近。成岩序列、热演化程度分析等综合研究认为长8油藏是一个连续成藏过程,该过程包括3期主要充注,其中晚期充注代表了主成藏期,储集层具有先致密后成藏的特征。
[Abstract]:The methods of physical crushing, acid treatment and step-by-step extraction were used to separate hydrocarbons of different occurrence states in reservoir samples, and then the components of hydrocarbons were analyzed by gas chromatography-mass spectrometry (GC-MS), and the relationship between hydrocarbons and their filling times were studied by fluorescence spectroscopy and homogenization temperature of inclusions. There are four kinds of hydrocarbons in Chang 8 oil-bearing sandstone of Yanchang Formation of Triassic in Erdos Basin, namely free hydrocarbon, closed hydrocarbon, carbonate cemented inclusion hydrocarbon and feldspar and quartz inclusion hydrocarbon. The content of free hydrocarbon is predominant in the extract with an average of 93.4%. Fluorescence spectra of inclusion hydrocarbon lambda_ (max), QF_ (535) and Q- (650/500) and other parameters showed that the hydrocarbon maturity of feldspar, quartz and carbonate cemented inclusions increased in turn, and the fluorescence spectra of inclusions in feldspar and quartz were similar, but different from those of carbonate inclusions. It is clear that the thermal evolution degree of feldspar and quartz inclusion hydrocarbon, carbonate cemented inclusion hydrocarbon, closed hydrocarbon and free hydrocarbon increases in turn, and the thermal evolution degree of free hydrocarbon and closed hydrocarbon is similar. Note that late filling represents the main reservoir forming stage, and the reservoir is characterized by tight accumulation.
【作者单位】：低渗透油气田勘探开发国家工程实验室;中国石油长庆油田公司;中国科学院地质与地球物理研究所兰州油气资源研究中心;
【基金】：国家科技重大专项“大型油气田及煤层气开发”(2016ZX05050;2011ZX05001-004)
【分类号】：P618.13

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