鄂尔多斯盆地直罗油田长8油层组储层特征研究

The reservoir characteristics of Chang 8 oil-bearing Formation in the Zhiluo oil field of Ordos Basin

本文应用岩石薄片、铸体薄片、扫描电镜、压汞实验等测试分析资料,对直罗油田延长组长8油层组储层的岩石学特征、物性特征、孔喉结构及孔喉类型等进行深入研究,试图探明该储层储集性能,为该区的勘探工作打好基础。结果表明,以水下分支河道沉积为主体的长8油层组储集砂体主要为长石砂岩、岩屑长石砂岩,成分成熟度较低,结构成熟度中等;储集空间为粒间孔、粒内溶孔和晶间孔;储层物性较差,为典型的低孔低渗储层。物源方向、沉积相的展布控制了储层平面上的物性;垂向上压实作用和胶结作用对储层物性起破坏作用,溶蚀作用则对储层物性的改善有建设作用。

With the methods of rock section, cast section, scanning electron microscope, pressured mercury testing data we made a deep research of the Zhiluo oilfield Chang 8 reservoir＇s lithology, physical properties, pore throat structure and pore throat types in the paper. This study trying to make a clear inquiry of this area＇s reserve property and which lay a significant foundation for the further work. The result defines the Chang 8 reservoir, deposited in subaquatic distributary channels, are mainly made up of feldspathic sandstone, debris-feldspathic sandstone. With interparticle pore, intragranular dissolved pore and intercrystal pore, the reservoir is characterized by low compositional maturity and middle texture maturity, which had a poor physical property and it is typical low porosity and low permeability reservoir. In the plane, the reservoirs＇ physical property is controlled by provenance and sedi-mentary face zones, in vertical direction, the compaction and cementation lead poor reservoir＇s physical property and dissolution is favorable to reservoir property.