疏松砂岩储层敏感性评价方法

疏松砂岩胶结差,不能钻取柱状岩心,因此无法用常规储层敏感性评价方法进行评价。建立疏松砂岩敏感性评价方法即气体流速法和回收法,利用气体流速法测定岩心的速敏指数,通过流体动能定理,推导气测法测定岩心速敏的临界流速计算方法。给出利用回收法测定储层的水敏、盐敏、碱敏和酸敏特性的计算方法和敏感指数划分原则。结果表明:回收法适合于测定岩心的水敏、盐敏、碱敏和酸敏特性,适合于疏松和/或未胶结砂岩储层的敏感性测定;研究方法操作简便、理论依据充分、数据结果可靠。

Evaluation methodology of formation sensitivity for unconsolidated sandstones

The conventional evaluation methods for the formation sensitivity are not applicable to the unconsolidated sandstones because of its unconsolidation, which leads to be unable to get columnar cores. The evaluation methods for unconsolidated sandstone sensitivity were established, which are gas flow rate method and recovery method, respectively. The gas flow rate method measures the velocity index of cores. Then, the critical flow rate of the velocity index was deduced using gas-testing method by kinetic energy theorem of fluid. And the sensitivity calculation formulation and sensitivity index dividing principle of water, salt, alkali and acid were given by recovery method. It is found that the recovery method is fit for water sensitivity, salt sensitivity, alkali sensitivity and acid sensitivity. The results show that the method is easy to proceed, and has a firm theoretical foundation. And the experimental data are reliable.