??????????????????????????

盐水钻井完井液对防止地层中的盐膏层溶解、粘土矿物发生水化膨胀分散，从而导致井壁不稳定和储层产生水敏损害具有很好的作用。然而，研究表明，高矿化度的钻井完井液对干气层会产生严重的伤害，渗透率损害率高达90％。分析研究其损害机理。主要原因是在干气返排驱替过程中，高矿化度盐水钻井完井液漶液中的盐组分会形成盐结晶堵塞储层孔道。中还介绍了防治这种损害的技术对策。

Mechanism and Countermeasures of Gas Reservoir Damage Caused by High-Salinity Brine Drilling-Completion Fluid

The brine drilling completion fluid can play an important role in preventing the occurrence of hole unstability and the formati on of reservoir water sensitive damage caused by the dissolustion of anhydrock salt beds and the hydration swelling and dispersion of clay minerals in strata .Research results,however,indicated that the gas reservoir damage caused by high salinity drilling completion fluid was very serious and the damage rate of pe rmeability was up to 90%.The damage mechanism is that the reservoir po re passages were plugged by the salt crystals formed from the high salinity bri ne drilling completion fluid in the process of back flowing displacement with dry gas.The technical countermeasures of preventing and controlling such a damag e are introduced in the paper also.