油藏非均质性及聚油史初探

PRELIMINARY APPROACH TO COMPOSITIONAL HETEROGENEITY AND ACCUMULATION HISTORY OF RESERVOIR

本文利用热解和热蒸发气相色谱分析技术，研究了塔里木轮南油田三叠系油藏剖面上储层的含油性和原油组成变化，发现低孔渗层段油砂的含油性低，原油的成熟度较低，正烷烃呈前峰型分布；高孔渗层段含油性高，原油成熟度较高，正烷烃里后峰型分布；孔渗中等的油砂中含油性和原油组成性质介于两者之间。油藏中不同孔渗层段的这种原油组成非均质性能反映油藏的聚油史。

Abstract Applying the techniques of pyrolysis and thermal extraction, the variations of oil content and composition in the Triassic reservoir of Lunnan oilfield, the Tarim Basin. are studied in this paper. It has been found that the intervals with low porosity and permeability have a low content of oil, and less matured, and its distribution of n-alkane is predo minated by a front peak; while the intervals with high porosity and permeability contain more and matured oil with a predominance of higher carbon number n-alkanes; the petroliferousness and composition of oil from intervals with middle porosity and permeability range from the two above. The oil compositional heterogeneities of intervals with different porosities and permeabilities within a reservoir may reflect its accumulative history.