摘要
为研究未熟油与成熟油混合后生物标志化合物参数变化,选择苏北盆地的两个成熟度相差悬殊的油样按不同比例混合,并将混合油样进行族组分分离,对饱和烃进行了气相色谱和色谱-质谱分析。结果表明,混合样的指标与混合比例呈不同的变化规律,正烷烃和萜烷等参数与混合比大致呈线性变化,而甾烷等参数与混合比呈非线性变化。造成这一差别的原因主要是混合双方中的甾烷、萜烷、正烷烃等化合物质量分数存在的差异。通过计算证实,混合双方的化合物质量分数相差较大时,混合样中有关参数与混合比呈“非线性”变化并总是倾向于质量分数大的一方,直到低质量分数一方混入比占绝对优势时才消失,此现象被称为流体混合中的“浓度-特征贡献比”分配原理。由此说明,混合比例的确定不能仅以指标为依据,而首先要弄清有关化合物的原始质量分数,那些仅根据甾烷成熟参数认定的“未熟油”,实际可能是以成熟油为主的混合油。
An immature oil sample from Tang-6 Well and a mature oil sample from Sha-7 Well in Subei basin are selected and mixed each other with different ratios so as to investigate changes between biomarker indices. The saturated hydrocarbon separated from the mixed samples is analyzed by GC and GC-MS, respectively. The study shows that different changes occur in mixed sample indices and mixed ratio, e.g., n-alkanes and terpenes parameters assume linear changes approximately, but others (e.g. steranes) assume nonlinear ones. The reasons caused are that the concentration of steranes, terpenes and n-alkanes in the immature oil differs from that in the mature oil. It is indicated from estimation that when the difference of the concentration among them are big, they appear in nonlinear change and tend toward increasing concentration, and this trend doesn't disappear until compounds of low concentration account for absolute predomination. The phenomenon is called the allocation principle of concentration-feature contribution ratio in the mixed oils. The results show that the mixed ratio is not only dependent upon biomarker indices, but also, it is more important to make clear the original concentrations related to these compounds. The ″immature oil″ pre-recognized from steranes maturity parameters could be the mixed oil dominated by the mature oil.
出处
《新疆石油地质》
CAS
CSCD
2004年第3期267-269,282,共4页
Xinjiang Petroleum Geology
