A New MIC Control Strategy in Low Velocity Gas Gathering Pipelines

Internal corrosion related failures in oil and gas gathering systems have been on the rise, especially where the operating conditions are such that computer corrosion modeling software predictions indicate a low risk.  The failure rate is, in most cases influenced by two major factors, the undiagnosed effect of microbially influenced corrosion (MIC) mechanisms and secondly the use of corrosive chemicals used to treat sessile and planktonic bacteria in these systems.  Low velocity gas-gathering systems are particularly difficult to treat for MIC as a result of pigging challenges and the use of biocides which concentrate in the water over time.  These concentrates can be extremely corrosive to the pipeline under common operating conditions.  Here we report a new water soluble quaternary ammonium compound, didecyldimethyl­ammonium bicarbonate/carbonate (DDABC), which has been evaluated as an MIC corrosion control agent via both standard electrochemical tests and MIC control evaluations (SRB, AB, APB).  Supporting data in the form of both lab and field tests indicate this inhibitor is extremely effective in competitive evaluations against glutaraldehyde, THPS, and quaternary ammonium chloride based systems on both sessile and planktonic contaminations.