Marine growth in cooling plant at drilling installation, Nigeria

Abstract

The study considers the probability and nature of marine growth (biofouling) in a cooling water plant to be installed at the Nnwa field offshore Nigeria. The cooling water will be taken from approximately 1000 m depth. Literature data and reports from existing installations using deep-water in tropical areas suggest that the main problem will be growth of micro-organisms (microfouling) on the lining of tubes and tunnels. The most relevant data have been reported from an OTEC test facility in Hawaii. Water samples taken in situ had a high content of nutrients and organic matter, suggesting that the living material mainly consists of bacteria. Presumably not more than infrequent measures to counteract growth will be needed, e.g by intermittent application of chlorine. The growth may depend on the materials selected for the lining of the tubes. References are given to literature and to R&D institutions working with biofouling from which further information may be sought.