东营凹陷乐安油田草4块沙四段储层敏感性研究

Study on reservoir sensitivity of Member 4 of Shahejie Formation in Block Cao4,Le'an Oilfield,Dongying Sag

针对油田开发过程中出现的问题,应用薄片、全岩矿物组分、X衍射、扫描电镜、物性、流体化验等资料,分砂层组对乐安油田草4块沙四段储层岩石成分、流体性质和物性特征进行了分析;通过敏感性流动实验对储层各种敏感性进行了研究。结果表明,3砂层组表现为中等偏强-强水敏、强酸敏、中等碱敏,4砂层组表现为弱-中等偏弱水敏、中等酸敏、弱碱敏;3、4砂层组均为强-极强盐敏,但临界矿化度不同;均不存在速敏性。分析了各种敏感性的成因机制,提出了抑制储层敏感性的措施。

Aimed at the problem in oilfield production, the rock ingredient, fluid properties and petrophysical character of Member 4 of Shahejie Formation in Block Cao4 of Le＇an Oilfield were analyzed by sands group using the data of thin section, full rock mineral component, X--ray diffraction, electron microscope scanning, petrophysical property and fluid assay. All kinds of reservoir sensitivities were researched on sensitivity flowing experiment. The results show there exist middle to strong or strong water sensitivity, strong acid sensitivity, middle alkali sensitivity in the three sands group; there exist weak or middle to weak water sensitivity, middle acid sensitivity, weak alkali sensitivity. There are strong or extremely strong salt sensitivity and no speed sensitivity in the three and forth sands groups, but the critical salinities are different. The cause mechanisms of the sensitivities were analyzed. And the measurements of restraining the reservoir sensitivities were put forward.