An oil producer in the northern U.S. had high-shear corrosion challenges and unfavorably high oil-in-water (OIW) counts in its sour production systems. The incumbent corrosion inhibitor was likely contributing to the OIW challenge and, while quite effective at controlling general corrosion, was still allowing unacceptably high rates of pitting to occur. Water clarifiers had proven ineffective to break the tight OIW emulsions, and residual oil levels averaged around 1500 ppm at the FWKO.
The corrosion-monitoring program in the fi eld had been relying on metal-loss coupons to measure general corrosion rates. This program was not looking at pitting corrosion—the most pernicious mechanism leading to the vast majority of failures. The customer asked Baker Hughes to help identify cost-effective solutions to solve the water quality and corrosion challenges.
Baker Hughes started with altering the corrosion monitoring program to better suit the production conditions in the field. Flush-mount coupons were installed to deliver more realistic corrosion rates relative to the rod coupons that had been used historically. A localized corrosion monitoring program was then initiated that focused on quantitative measurement of both the population and the depth of the pits found on the coupons.
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