ULTRASONIC INSPECTION PROMPTS CHEMICAL INHIBITOR PROGRAM (REPRINTED FROM OIL AND GAS JOURNAL, APRIL, 1991)

This article provides a case history of internal corrosion that occurs in the dead and intermittent flowlines of the Trans-Alaska Pipeline system (TAPS) and describes methods used to mitigate corrosion with inhibitors. Internal corrosion occurred predominantly in low-velocity piping where emulsified water precipitated out of the crude and supported microbiological corrosion. To maintain pipeline integrity and minimize pressure derating of TAPS crude piping, a large scale mitigation program using chemical inhibitors was initiated in 1989. A system of manual batch treatment was developed to treat the numerous dead legs in the pump station facilities. The project also included a system for monitoring inhibitor effectiveness.