Acid Corrosion Inhibitors

A different class of corrosion inhibitors addresses the case when concentrated hydrochloric acid solution (15% or more HCl) is used as a stimulation/cleaning treatment for production wells. This can be used, for example, to dissolve and remove bothersome calcium carbonate or other acid-soluble deposits.

A significant side-effect of these acid treatments is a very high corrosion rate for all metal that is exposed to the acid solution. Fortunately, the typical treatment time of exposure to such concentrated acid is fairly short, but specialty corrosion inhibitors are required to reduce the corrosion rate to an acceptable level.

ChemEOR has designed a series of acid inhibitors to be used especially as an additive for these HCl acid solution treatments. ChemEOR products are highly effective and designed to give excellent corrosion protection on casing, tubing and downhole tools in contact with hydrochloric acids up to 275˚F (135˚C). Commonly used alloys N-80, J-55, 13Cr and 22Cr can be effectively inhibited. With their molecular level optimized formulation, our products outperform the most commonly used propargyl alcohol acid inhibitor. ChemEOR acid corrosion inhibitors are soluble in acid treatment solutions and are compatible with all other additives it may contain.

Laboratory coupon tests using 20% HCl for 24 hours at 75 C in a brine of 0.5% salinity show a very favorable result for a ChemEOR product versus the control case with no chemical protection and another commercial acid corrosion inhibitor.

Applications

• • Used typically in 15% HCl stimulation fluids at temperature up to 275°F (135°C).
• • Protects casing, tubing, and tools with N-80, J-55, 13Cr, 22Cr materials from corrosion by strong acid.
• • Soluble in water and compatible with common oilfield brines.
• • Recommended treatment is 2.5-10gpt (0.25-1%).
• • Performance can be improved with intensifiers at higher temperature.

HIGH PERFORMANCE
Effective acid corrosion inhibitor for use in well acidizing, fracture acidizing and stimulation operations. Outperforms propargyl alcohol at the same concentration in lab tests.

SUPERIOR THERMAL STABILITY
Excellent corrosion protection against hydrochloric acid up to 275°F (135°C). Higher dosage or intensifiers can be used when higher temperature and severe conditions are anticipated.

FLUID COMPATIBILITY
Superior function compatible in most common field fluids.

GOOD ENVIRONMENT PROFILE
Not on the regulated list of EPA priority pollutants or the EPA secondary contaminants list, nor the European Chemicals Agency (ECHA) candidate list of Substances of High Concern (SVHC).