华庆地区长6 油层组黏土矿物类型及其对储层物性的影响

在薄片、X 射线衍射和扫描电镜分析基础上，研究了鄂尔多斯盆地华庆地区长6 油层组砂岩中黏土 矿物的主要类型、赋存方式及其对储层物性的影响。结果表明：长6 油层组砂岩中的黏土矿物主要为绿 泥石、伊利石和混层伊利石/蒙皂石，黏土矿物总量平均为4.55%；自生绿泥石主要以孔隙衬里方式产出， 对深埋藏砂岩的储集空间具有显著的保护作用；伊利石和混层伊利石/蒙皂石主要以孔隙桥接或孔隙充填 方式产出，其大量存在会堵塞孔隙喉道、减小孔喉半径，从而对储层物性产生负面影响；高岭石在华庆地 区长6 油层组砂岩中不发育，是由于高含量杂基导致长6 油层组砂岩在酸性流体出现之前已基本完成压 实作用，且长7 烃源岩有机质演化过程中产生的酸性流体对其影响十分有限，使其缺乏足够的粒间孔隙 和活跃的酸性流体沉淀高岭石。

Types of clay minerals and its effects on reservoir properties of Chang 6 oil reservoir set in Huaqing area,Ordos Basin

Based on thin section analysis,X-ray diffraction and scanning electronic microscope analyses,this paper studied the types,occurrence of clay minerals and its influence on reservoir properties of Chang 6 oil reservoir set in Huaqing area.The result shows that the clay minerals in Chang 6 oil reservoir set mainly consist of chlorite,illite and illite/smectite mixed layer,and the average content of clay minerals is approximately 4.55%.Authigenic chlorite commonly occurs as pore-lining cement,which is beneficial to protect porosity of deeply buried sandstones.The occurrence of illite and illite/smectite mixed layer is pore bridging or pore filling,which will block up pore spaces and reduce throat radius,and have negative effect on sandstone reservoir.Authigenic kaolinite in Chang 6 oil reservoir set in Huaqing area is not developed.High matrix content makes the reservoir experience intense compaction earlier than acidic fluid,and the influence of acidic fluid from Chang 7 hydrocarbon rocks is limited for Chang 6 oil reservoir set,both of them result in the lack of intergranular volume and active acidic fluid for kaolinite.