Acidizing corrosion inhibitor

Claim 1

AN ACIDIZING PROCESS FOR THE REMOVAL OF CALCAREOUS INCRUSTATION FROM A FERROUS METAL SURFACE WHEREBY CORROSION OF THE METAL SUBSTRATE IS INHIBITED WHICH COMPRISES CONTACTING SAID INCRUSTED SURFACE WITH AN AQUEOUS SOLUTION OF A STRONG MINERAL ACID CONTAINING FROM ABOUT 0.1 TO 5% OF THE PRODUCT OBTAINED BY REACTING AT A TEMPERATURE BETWEEN ABOUT 65*C. AND 200*C. FROM ABOUT 0.7 TO 0.3 MOLE OF A MERCAPTO COMPOUND SELECTED FROM THE GROUP CONSISTING OF THIOL ACETIC ACID, MERCAPTO SUCCINIC ACID, TOLUNE THIOL, AND O-MERCAPTO-BENZOIC ACID, WITH CORRESPONDINGLY FROM ABOUT 0.3 TO 0.7 MOLE OF AN ORGANIC NITROGEN COMPOUND SELECTED FROM THE GROUP CONSISTING OF A 2-ALKYL-PYRIDINE, THE ALKYL GROUP OF WHICH CONTAINS FROM 4 TO 12 CARBON ATOMS, AN O-ALKYL-ANILINE THE ALKYL GROUP OF WHICH CONTAINS FROM 1 TO 6 CARBON ATOMS, A POLYETHYLENE POLYAMINE, A N-ALKYL-TRIMETHYLENE-DIAMINE IN WHICH THE ALKYL GROUP IS DERIVED FROM A FATTY ACID, AND AN IMIDAZOLINE SUBSTITUTED IN THE NUMBER ONE POSITION WITH AN ALIPHATIC GROUP CONTAINING A RADICAL SELECTED FROM THE CLASS CONSISTING OF HYDROXY, AMINO AND IMINO AND SUBSTITUTED IN THE NUMBER TWO POSITION WITH A C12-C22 HYDROCARBON GROUP SELECTED FROM THE CLASS CONSISTING OF ALKYL AND ALKENYL.