ABSTRACT
Corrosion Control for above ground crude oil storage tanks presents a real challenge due to the factors like large and complex tank geometries, the proximity of anodes to the tank bottom, tank design, electrical isolation etc. The issue is further complicated by the provisions such as leak detection system, secondary containment or specialized foundation designs.
Inadequate / inappropriate corrosion control may pose serious environmental and safety hazards, in the event of leakage / seepage from the large crude oil storage tanks, which handle enormous amounts of highly flammable hydrocarbons. Various solutions implemented to achieve effective corrosion control in above ground crude oil storage tanks at various locations by Energy major in India, have been described to evaluate effectiveness of the implemented solutions.
The effectiveness of the implemented corrosion control methods has been evaluated by periodic inspections during Maintenance and Inspections over a period of more than twenty years.
INTRODUCTION
Crude Oil is a naturally occurring, highly inflammable hydrocarbon liquid is refined, to yield various petroleum components through fractional distillation. Before transportation to Refineries, Crude Oil is stored in bulk quantities, in large above ground storage tanks, to maintain desired stocks for continuous operation of Pipelines and to maintain crude oil supplies to Refineries for uninterrupted operation. Such storage of highly inflammable crude oil in storage tanks, primarily Steel tanks, brings into focus the primary potential of leakage and consequent probability of fire and explosion 1 due to the combustible nature of crude oil. Environmental impact of crude oil discharge (leakage / seepage) depends on the type of crude oil, discharge quantities, spill circumstances (e.g, weather conditions, speed and effectiveness of response) & eco-system specific characteristics (e.g. land, stream, river, pond, wetland etc) 2. Leakage of even small quantities of crude oil can have significant adverse effects on public and private property, in addition to potential fire hazard and explosion.
