Evaluation of corrosion inhibitors

Claim 1

A METHOD FOR DETERMINING CHANGE IN CORROSIVITY AND CONTROLLING THE SAME IN PRODUCING OIL WELLS WHICH COMPRISES WITHDRAWING A PORTION OF AN OIL-BRINE MIXTURE FROM THE WELL, PLACING THE WITHDRAWN OIL-BRINE MIXTURE IN A CONTAINER AND IMMERSING THEREIN A STANDARD METALLIC TEST STRIP HAVING A COMPOSITION SIMILAR TO THE COMPOSITION OF WELL EQUIPMENT METALS, SAID STRIP HAVING PREVIOUSLY BEEN TREATED TO REMOVE SURFACE CONTAMINANTS, PERMITTING THE STANDARD TEST STRIP TO REMAIN IN SAID OIL-BRINE MIXTURE FOR A PERIOD OF TIME SUFFICIENT TO OBTAIN BUILD-UP OF WELL CONTAMINANTS ON SAID STRIP, IMMERSING A PLURALITY OF LIKE METAL TEST STRIPS INTO THE WITHDRAWAL LINE OF THE WELL DURING WITHDRAWAL OF THE OIL-BRINE MIXTURE, PERIODICALLY REMOVING ONE OF THE PLURALITY OF IMMERSED METAL TEST STRIPS FROM THE OIL-BRINE MIXTURE DRAW-OFF LINE, IMMERSING SAID STRIP IN A PORTION OF WELL BRINE CONTAINED IN THE CELL OF A GALVANIC CIRCUIT, SAID CIRCUIT INCLUDING A DEVICE ADAPTED TO INDICATE E. M. F. GENERATION IN THE CELL, UTILIZING THE METALLIC TEST STRIP REMOVED FROM THE DRAW-OFF LINE AS THE CATHODIC TERMINAL OF SAID GALVANIC CIRCUIT, UTILIZING THE STANDARD METALLIC TEST STRIP AS THE ANODIC TERMINAL OF SAID CIRCUIT, MEASURING AT PREDETERMINED INTERVALS THE AMOUNT OF E. M. F. GENERATED IN SAID CELL UNTIL AN EQUILIBRIUM E. M. F. VALUE IS OBTAINED, SAID VALVE REPRESENTING THE CORROSIVE CONDITION OF THE WELL, AND ADDING CORROSION INHIBITOR TO THE WELL AS SUBSEQUENTLY DETERMINED EQUILIBRIUM VALUES BECOME INCREASINGLY NEGATIVE.

Claim 2

A METHOD FOR DETERMINING CHANGE IN CORROSIVITY AND CONTROLLING THE SAME IN PRODUCING OIL WELLS WHICH COMPRISES WITHDRAWING A PORTION OF AN OIL-BRINE MIXTURE FROM THE WELL, PLACING THE WITHDRAWN OIL-BRINE MIXTURE IN A CONTAINER AND IMMERSING THEREIN A STANDARD METALLIC TEST STRIP HAVING A COMPOSITION SIMILAR TO THE COMPOSITION OF WELL EQUIPMENT METALS, SAID STRIP HAVING PREVIOUSLY BEEN TREATED TO REMOVE SURFACE CONTAMINANTS, PERMITTING THE STANDARD TEST STRIP TO REMAIN IN SAID OIL-BRINE MIXTURE FOR A PERIOD OF TIME SUFFICIENT TO OBTAIN BUILD-UP OF WELL CONTAMINANTS ON SAID STRIP, IMMERSING A PLURALITY OF LIKE METAL TEST STRIPS INTO THE WITHDRAWAL LINE OF THE WELL DURING WITHDRAWAL OF THE OIL-BRINE MIXTURE, PERIODICALLY REMOVING ONE OF THE PLURALITY OF IMMERSED METAL TEST STRIPS FROM THE OIL-BRINE MIXTURE DRAW-OFF LINE, IMMERSING SAID STRIP IN A PORTION OF WELL BRINE CONTAINED IN THE CELL OF A GALVANIC CIRCUIT, SAID CIRCUIT INCLUDING A DEVICE ADAPTED TO INDICATE E. M. F. GENERATION IN THE CELL, UTILIZING THE METALLIC TEST STRIP REMOVED FROM THE DRAW-OFF LINE AS THE CATHODIC TERMINAL OF SAID GALVANIC CIRCUIT, UTILIZING THE STANDARD METALLIC TEST STRIP AS THE ANODIC TERMINAL OF SAID CIRCUIT, MEASURING AT PREDETERMINED INTERVALS THE AMOUNT OF E. M. F. GENERATED IN SAID CELL UNTIL AN EQUILIBRIUM E. M. F. VALUE IS OBTAINED, SAID VALVE REPRESENTING THE CORROSIVE CONDITION OF THE WELL, AND ADDING CORROSION INHIBITOR TO THE WELL AS SUBSEQUENTLY DETERMINED EQUILIBRIUM VALUES BECOME INCREASINGLY NEGATIVE.