Well wall collapse-preventing agent for drilling liquid and preparation method of well wall collapse-preventing agent

The invention discloses a well wall collapse-preventing agent for a drilling liquid and a preparation method of the well wall collapse-preventing agent. According to the collapse-preventing agent, polyether prepared from glycol, epoxyethane and epoxypropane and of which the molecular weight is 1000-5000 is used as a raw material, and methanesulfonyl chloride, organic amine, water of which the massis the same as that of the polyether, and sodium hydroxide of which the molar mass is the same as that of the methanesulfonyl chloride are sequentially added under the condition that the temperatureis 55-70 DEG C, so that the collapse-preventing agent is prepared. A synthesis preparation method is simple, the cost is low, and the collapse-preventing agent is suitable for industrial production. The well wall collapse-preventing agent for the drilling liquid, prepared by the method, has favorable blocking properties and shale inhibition properties, the temperature resistance is as high as 220DEG C, and the collapse-pre