EXTENDING PIPELINE LIFE THROUGH CORROSION CONTROL OPTIMIZATION WITH ATMOSPHERIC HYDROGEN SULFIDE MONITORING AND CAUSTIC SLUG DOSING

Significant cost savings were realized through deferred pipeline rehabilitation by increasing corrosion control for portions of the Martinez Transmission Line, a 6-mile long conveyance system consisting of three forcemain sections and three gravity sections, carrying approximately 1.3 MGD. A physical investigation of the transmission line delineated which segments required immediate replacement and which could be deferred. An average gaseous hydrogen sulfide control level of 5 ppm reduced corrosion rates significantly and could defer 4.6 million in pipeline rehabilitation costs for an additional 10 – 20 years. Original chemical control estimates with hydrogen peroxide were 220,000 per year. By optimizing chemical dosing through continuous monitoring of gaseous hydrogen sulfide and determining the regrowth following caustic slugging to reduce the continuous feed of chemicals, the chemical costs were reduced by 50,000 per year below the original estimates.