Corrosion Inhibition in Gas Condensate Wells By Intermittent Injection of Alkaline Solutions

Abstract

Experiments carried out by personnel of the Producing Research Laboratory of The Texas Company in efforts to reduce corrosion in deep gas condensate wells in the Gulf Coast area in which the casing is mudded off from the tubing indicate: Of two wells with open annuli through which chemicals may be pumped, one well has been treated with sodium carbonate since August 1949 and has shown no measurable corrosion increases in the tubing in two caliper surveys. Wells in the field produce about 1.5 barrels of water per MMCF of gas at their allowable rates of 4.5 MMCF daily. The water contains dissolved carbon dioxide and organic acids. Water collected at the surface has a pH of about 5.5 and contains about 130 PPM of dissolved iron. Lower flow rates produce water with higher pH and greater-dissolved iron content. Treatment of the well with 30 gal. per day of solution containing 2.5 lb. sal soda or sodium decahydrate per MMCF of produced gas costs approximately l5-20c per MMCF. Kontol sticks dropped for one year i...