FPSO Mystras is the latest in a series of FPSO's being jointly designed and built by IHC Gusto and SBM (Single Buoy Moorings). This vessel is destined for use in West African waters where no gas export or re-injection is possible at present. This means that the full field gas production must be flared, at least for the first 2 years of field life anyway. To maximise oil production it was desired to be able of flaring up to 100 MMSCFD of associated gas both with acceptable deck radiation levels and more difficultly deck noise levels within 85dBA.

Meeting the noise level with the original sonic flare proved impossible so a novel solution was devised. The flare tip design was adapted to operate at moderate (sub-sonic) velocity which reduced the noise output considerably while water injection was employed to compensate for the increased emissivity of the flame.

Water injection is very effective at reducing radiation as it both cools the flame and chemically promotes complete combustion.