The invention relates to the technical field of oilfield lining
pipe reinforcing operation, in particular to a method for leakage pre-plugging of a well cemented through a lining
pipe. The method comprises the following steps that 1, a
drill rod is tripped to 30-50 m of the upper portion of a perforation interval or a sleeve leakage point, and a packer is arranged on the position with 80-120 m distance from the upper portion of the perforation interval or the sleeve leakage point; 2, well flushing fluid is positively injected for one week, and then the packer is set; and 3, a plugging agent Ais injected to plug the perforation interval or the sleeve leakage point in advance, and the plugging agent A is composed of a water-based drive-adjusting
reagent, a
lignin particle plugging agent andwater. According to the method, before
well cementing construction,
chemical agents are injected to pre-plug the well sections, with
cement slurry prone to loss, of the perforation interval, a leakage loss point, the sleeve leakage point and the like, the
chemical agents in use are high in plugging rate and high in compression strength, a leakage loss layer can be efficiently plugged, leakage loss of
cement slurry in
well cementing construction through lining
pipe reinforcing is avoided, meanwhile, the plugging agent does not damage the oil layer, the
oil well production capacity is not affected, and smooth conducting of
well cementing construction is ensured.