NOVELTY - Treating (M1) wellbore involves: contacting a permeable treatment zone in fluid communication between a wellbore and a fluid reservoir with a treatment fluid comprising a clay stabilizer and formation protective material, with sufficient clay stabilizer and sufficient formation protective material and for a period of time effective to inhibit fines production and migration in the permeable treatment zone, where formation protective material comprises a water soluble metal salt, and optionally displacing a second fluid through treatment zone between the wellbore and the reservoir.    USE - For treating wellbore; for acidizing subterranean formation (claimed); for selectively locating, extending a fracture or a fluid channel; for enhancing the productivity of a subterranean formation penetrated by a well, e.g. a gas, oil or geothermal well.    ADVANTAGE - The method uses FPMs which act as a sacrificial barrier that is eaten away by acid and which reduces the amount of earth formation material eroded by the acid, e.g. carbonates in the earth; uses materials for protecting an earth formation so that acid in acidizing fluids does not cause undesirable formation erosion or so that unprotected areas are eroded more than protected areas.    DETAILED DESCRIPTION - Treating (M1) wellbore involves: contacting a permeable treatment zone in fluid communication between a wellbore and a fluid reservoir with a treatment fluid comprising a clay stabilizer and formation protective material, with sufficient clay stabilizer and sufficient formation protective material and for a period of time effective to inhibit fines production and migration in the permeable treatment zone, where formation protective material comprises a water soluble metal salt and optionally displacing a second fluid through the treatment zone between the wellbore and the reservoir, where the formation protective material comprises water-soluble metal salts, cationic metal salts, water-soluble aluminum salts, aluminum chloride, aluminum chlorohydrates, cloroaluminate, zirconium chlorides, zirconium tetrachloride, zirconocene dichloride, zirconium (III) chloride, zirconium salts and/or aluminum zirconium tetracholorhydrex glycine. An INDEPENDENT CLAIM is included for acidizing (M2) subterranean formation involving: providing a treatment fluid including a carrier fluid with formation protective material in it, injecting the treatment fluid into a subterranean formation, where formation protective material is applied to earth of the subterranean formation; and acidizing at least a portion of the subterranean formation, where the formation protective material is water-soluble metal salts and/or cationic metal.