The client had an urgent requirement to displace oil from pipework connected to 4 off storage cells on one of many platforms they are in the process of decommissioning in the north sea. The platform was of condeep style construction in 140m water with a concrete base with built in subsea storage cells.
A low density pumpable material was required to displace the oil, which had a density of 0.8, contained in the pipework that was connected to the storage cells. Aubin’s product development chemists identified the specific properties required to displace the oil and selected LiquiBuoy. Typically used for buoyancy applications, LiquiBuoy was recommended to our client because of its low density and pumpable nature. This product is water based with a density of 0.5 to 0.6 and is readily pumpable utilising diaphragm pumps, positive cavitation pumps or similar.
The solution was then tested and prepared for implementation in under two weeks from enquiry. Once offshore, the displacement material, LiquiBuoy was pumped from the deck of the platform using a diaphragm pump, via 2” hoses, into the pipework, displacing the oil back to the storage cells. LiquiBuoy, due to its low density, floated on top of the oil in the storage cells, leaving the collected oil and displacement fluid in distinct phases, allowing easy recovery of oil from the cells.
The pipework was cleared of hydrocarbons and the displaced oil was maintained as a distinct phase for re-use or sale. The client considered this urgent operation a success and was pleased with the turnaround time and delivery of Aubin’s solution.