Consolidation

A method of strengthening subterranean formation by drilling and completing a wellbore penetrating at least one unconsolidated or weakly consolidated formation, the method comprising: (a) drilling at least one interval of the wellbore that penetrates the unconsolidated or weakly consolidated formation using a drilling mud comprising a base fluid comprising an aqueous phase containing up to 25% weight by volume (%w/v) of a water soluble silicate, wherein the drilling mud has an acid-soluble particulate bridging solid suspended therein that is formed from a salt of a multivalent cation, wherein the salt of the multivalent cation is capable of providing dissolved multivalent cations when in the presence of an acid; (b) subsequently introducing a breaker fluid containing an acid and/or an acid precursor into the wellbore; (c) allowing the breaker fluid to soak in the interval that penetrates the unconsolidated or weakly consolidated formation for a predetermined period and strengthening formation by reacting with silicate now present in formation; and (d) removing the breaker fluid.