Method of inhibiting corrosion of metals

Claim 1

THE PROCESS OF PREVENTING THE CORROSION OF METALS WHEN EXPOSED TO CONTACT WITH CORROSIVE OIL WELL FLUIDS WHICH COMPRISES INCORPORATING INTO THE WELL FLUIDS A SMALL BUT SUFFICIENT QUANTITY OF A REACTION PRODUCT PREPARED BY SPONTANEOUSLY REACTING ABOUT ONE MOL OF DIETHYLENETRIAMINE WITH ABOUT ONE MOL OF AN ALDEHYDE SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC ALDEHYDES AND AROMATIC ALDEHYDES, HEATING THE REACTION MIXTURE AT A TEMPERATURE SUFFICIENTLY HIGH, BUT NOT IN EXCESS OF ABOUT 190* C., AD FOR A PERIOD OF TIME SUFFICIENT TO DRIVE OFF WATER FROM IN THE REATION WHEREBY TO FORM AN INTERMEDIATE REACTION PRODUCT BETWEEEN THE AMINE AND THE ALDEHYDE, COOLING THE MIXTURE, SPONTANEOUSLY REACTING THE INTERMEDIATE REACTION PRODUCT WITH AN ADDITIONAL MOLE OF AN ALIPHATIC ALDEHYDE, AND HEATING AT A TEMPERATURE SUFFICIENTLY HIGH, BUT NOT IN EXCESS OF ABOUT 190* C., AND FOR A PERIOD OF TIME SUFFICIENT TO DRIVE OFF WATER FORMED BY THE REACTION OF THE ADDED ALDEHYDE WITH THE INTERMEDIATE REACTION PRODUCT AND THEREAFTER CAUSING THE WELL FLUIDS TO FLOW IN CONTACT WITH THE METAL TO BE PROTECTED.