The invention provides a 180 DEG C-resistant microcapsule type cementing wall-fixing agent for water-based
drilling fluid as well as a preparation method and application thereof, and belongs to the technical field of drilling. The preparation method of the wall fixing agent comprises the following steps: (1) respectively adding the macromolecular hydrophilic
colloid and the emulsifier into deionized water, and stirring until the macromolecular hydrophilic
colloid and the emulsifier are completely dissolved to obtain a water phase; (2) adding phenolic resin, the MUF
prepolymer solution and nano SiO2 into an
organic solvent under a stirring condition, and uniformly stirring to obtain an
oil phase; (3) adding the
oil phase obtained in the step (2) into the water phase obtained in the step (1), and carrying out shear emulsification to obtain an oil-in-water
emulsion; and evaporating to remove the
organic solvent in the
system, filtering, washing, and
drying to obtain the product. Under the multi-element synergistic effect of
hydrogen bonds or coordinate bonds,
Van der Waals force and the like, the microcapsule type cementing wall-fixing agent can accelerate the interface to form a compact cemented
network structure, the cementing strength of rock particles is remarkably improved, and the purpose of strengthening the stability of a well wall is achieved.