The C-NLOPB is responding to a report from Husky Energy of a release of approximately 4000 litres of synthetic-based mud (SBM) onto the deck of the GSF Grand Banks on April 8. Operations were suspended when the incident occurred and clean-up response was initiated. It currently appears that little, if any, mud was spilled to sea. The Stand-by Vessel conducted a survey of the area around the rig during daylight hours and observed no sheen or discoloration on the surface. The C-NLOPB is following-up with the Operator.
SBM is a heavy, dense fluid used during drilling operations to lubricate the drill pipe and balance reservoir pressure. Because of its weight, the mud sinks rapidly in the water column and rests on the sea floor. The synthetic-based oil used in SBM is a food-grade oil of low toxicity. Because of this, effects of SBM spills typically are limited to within tens of meters of a well site and are associated with physical smothering due to seabed coverage by the mud.