Abstract: Random terpolymers are characterized for being tolerant to high concentrations of divalent ions, such as calcium, magnesium, strontium and barium, and that for their application in the reservoir or production rig, treated water, sea water and/or connate water can be used as means of transportation. Furthermore, the terpolymer also can be used to inhibit and disperse mineral scales presents in cooling system and boiler employed in the chemical and oil industry. Also, random terpolymers of the present invention have the characteristic of complying with environmental standards established internationally and are classified as particularly non-toxic, so it can be used in pipes and equipment of the petrochemical industry and with the use characteristic freshwater and seawater from offshore and onshore facilities.