低渗透储层水锁损害研究新进

水锁效应是在油气开发过程中，当钻井液、完井液等外来流体侵入储层后，造成近井壁处油气相渗透率降低的现象。水锁效应是影响油气井生产的主要因素，尤其是在低渗透储层，这种影响更显著。低渗透储层通常是指渗透率较低的砂岩储层．其他还有在一定次生改造条件下可以成为储层的泥岩、岩浆岩和变质岩等。油气层从打开直至枯竭的全过程中。不同类型的工作流体会改变地层原始平衡状态，使油气层的原始渗透性受到损害。研究水锁效应基本原理、实验方法、评价指标及其预测方法，对提高低渗透储集层的采收率具有重要意义。调研了目前水锁损害实验方法以及模拟预测等方面的研究进展，从实验的基本原理、常规分析方法、辅助指标以及水锁损害模拟与预测模型等方面，对水锁损害研究方法进行介绍。对岩心自吸以及驱替实验、蒸发作用的数学建模与计算、水锁指标的构建、水锁损害的计算机模拟、回归分析法、灰色预测法、神经网络法及灰色一神经网络预测法等相关研究成果进行总结，分析各实验方法的应用条件和不足。有助于理解现阶段水锁损害的研究方法，并为新方法的提出和应用提供基础。

Progress of the Study on Water Blocking Damage in the Low Permeability Reservoirs

Water blocking effect is a phenomenon that the permeability near wellbore drops when drilling flu id,well completion fluid and other allochthonous fluids invade into reservoirs during oil and gas development. It is one of the main influencing factors during oil and gas well production, especially in the low permeabili ty reservoirs.The low permeability reservoirs usually refer to the sandstone reservoirs with low permeability, and other mudstone,magmatic .rock and metamorphic rock which can turn into reservoirs under secondary re construction condition.During the whole process from reservoir opening to depleting,different types of working fluid may change original formation balance and result in different degrees of damage to original permeability of the oilgas reservoirs.The study of the mechanism,experimental method,assessment criteria and prediction technique of the water blocking effect is of important significance in improving recovery efficiency of the low permeability reservoirs.The current research progress on experiment methods,simulation and prediction of the water blocking damage is investigated,mainly focuses on the basic experiment principles,conventional analysis method,auxiliary indicators,as well as the simulation and prediction model of the water blocking damage.Be sides,the author also summarizes related research results comprehensively and systematically,such as core selfpriming, displacement experiment, mathematical modeling and calculation of evaporation, construction of wa ter blocking indicators,computer simulation of the water blocking damage,regression analysis method,grey prediction method,neural network method,grey neural network prediction method,etc.The application conditions and shortcomings of these methods are also the water blocking damage and provides analyzed.It helps to understand the present research method of basis for suggesting and applying of the new methods.