在对东营凹陷王家岗地区古近系沙河街组沙三、沙四段不同类型砂体储层岩石学特征、黏土矿物组合特征分析的基础上,探讨了不同类型砂体的潜在敏感性及其差异.结果表明,不同类型砂体的岩石学特征、黏土矿物组合特征有较大差异,对储层敏感性有较大的影响.河流及滨湖等近源砂岩的黏土矿物组合为伊/蒙混层+伊利石+高岭石,伊/蒙混层矿物为主；三角洲前缘及滩坝砂体的黏土矿物组合为高岭石+伊利石+伊/蒙混层,高岭石含量高；半深湖、深湖及浊积扇砂体中伊利石、绿泥石含量较高,为伊利石+绿泥石+伊/蒙混层组合类型.储层敏感性明显受沉积环境和埋深的影响,河流及滨湖等近源砂岩具有中—偏强水敏性,三角洲前缘及滩坝砂体具有中—弱的速敏性,三角洲前缘与较深湖接触带具有一定的酸敏性,浊积扇砂体储层具有弱水敏性,泛滥平原、浊积扇扇缘等细粒相带具有较强的应力敏感性.根据沉积相带展布可以预测储层敏感性特征,并制定油层保护措施.%On the basis of the characteristic analyses of the petrology and clay mineral combination for different types of sandbody reservoirs in Palaeogene Shahejie Formation' s No. 3 and No. 4 Members in Wangjiagang area of Dongying Sag, the potential sensitivities and their differences for these sandbodies are explored. The results show that there are a great differential in the above characteristics for different kinds of sandbodies and moreover possess much more serious influences on reservoir sensitivities. The clay mineral assemblage of the proximal sandstones such as those nearby rivers, lakeshores is mainly characterized by the mixed layer of illite and smectite, illite and kaolinite, taking the minerals of the mixed layer of illite and smectite as main form; the clay mineral combination of the sandbodies in delta front and beach bar facies include kaolinite, illite, and illite/ montmorillonite mixed layer, the content of kaolinite is rather higher; So are the contents of illite and chlorite in the sandbodies of hemi-deep lake, deep lake and tuibidite fan, they belong to the assemblage of illite, chlorite and illite/ montmorillonite mixed layer. Reservoir sensitivity is obviously influenced by the sedimentary environments and buried depth: the proximalsandstones such as ones in rivers, shore lake and so forth possess medium-slightly strong water sensitivity; the sandbodies in delta front and beach bar are characterized by medium-weak velocity sensitivity; those in the contact belt between the delta front and deeper lake have a certain acid sensitivity; the sandbody reservoirs in turbidite fan have slightly weak water sensitivity; the fine-grained facies such as flooded plain, turbidite fan fringe and so forth display rather stronger stress sensitivity. According to the spread and distribution of the sedimentary belts, the characteristics of reservoir sensitivity can be predicted and furthermore the protecting measures to the oil layers can be established.
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