吴起地区长6储层特征及成岩作用研究

Study on Reservoir Characteristics and Diagenesis of Chang 6 in Wuqi Area

通过铸体薄片、扫描电镜、高压压汞、X衍射等实验检测方法,对鄂尔多斯盆地吴起地区长6储层的储层特征及成岩作用展开了研究,在分析各成岩作用基础上,探索了各成岩作用对储层物性的影响规律。结果表明:研究区长6储层的岩性主要为中-细粒长石砂岩,根据孔隙组合类型将储层分为溶孔-粒间孔型、粒间孔-溶孔型和微孔型储层,物性依次由优变差。研究区压实作用表现为破坏性成岩作用,造成孔隙度损失约20.15%,渗流能力变差。胶结作用整体上造成孔隙度损失27.82%,但其中碳酸盐胶结为破坏性成岩作用,绿泥石胶结属于建设性成岩作用。溶蚀作用对物性有积极的改善作用,增加孔隙度2.84%,随溶蚀率增大物性均有变好趋势。

In this paper,the reservoir characteristics and diagenesis of the Chang 6 reservoir in the Wuqi area of Ordos Basin were studied using the experimental methods of cast thin section,scanning electron microscope,high pressure mercury injection,and X-ray diffraction.The diagenesis and its effect on reservoir properties were studied.The results show that the lithology of Chang 6 reservoir is mainly medium-fine feldspathic sandstone.According to the type of pore combination,the reservoir is divided into:Solution pore-intergranular pore type,Intergranular pore-solution pore type and Microporous reservoir,and the physical properties are changed from excellent to poor.The compaction in the study area is characterized by destructive diagenesis,resulting in porosity loss of about 20.15%and poor seepage capacity.The cementation results in a loss of 27.82%of the porosity as a whole,but the cementation of carbonate is a destructive diagenesis.The chlorite cementation is a constructive diagenesis.Corrosion has a positive effect on the physical properties,increase the porosity of 2.84%,with the dissolution rate increases the physical properties have a good trend.