In July 2004 BP was required to take its produced water degasser on the Schiehallion FPSO offline for essential upgrade work. Without a replacement technology BP potentially faced a production shutdown during repairs.
CETCO offered its CrudeSep® technology to BP as a temporary degasser vessel. In addition to oil and solids removal the CrudeSep® also acts as an effective degassing vessel. As best available technology, CETCO was requested to install the unit as a temporary replacement to the existing degasser.
CETCO mobilised a 48” diameter vessel CrudeSep® skid to handle up to 40,000 bbls/d of produced water. CETCO’s scope of work was to remove gas and ensure all produced water discharged overboard met the environmental discharge limit concentration of <40 ppm.
BP informed CETCO that historically a large amount of oil wet solids are returned through the Schiehallion produced water system which contributes to oil in water handling problems. A benefit of the CrudeSep® is its excellent solids removal capabilities. Solids removal in addition to oil removal ensured that produced water discharged overboard from the CrudeSep® remained on average <30 ppm.
The total volume of solids was decreased by over 98% from inlet to outlet. This volume reduction is equivalent to the removal of 3.5 litres of solids per cubic metre of fluid processed with less than 50mls per cubic metre remaining in solution.