In 1972, four companies, that will become the OPCAL joint venture, obtained a licence of exploration for oil in the North Sea, leading to the “discovery” of the Piper oilfield the next year. They built the platform, pipelines and onshore support structures, and the production started in 1976. Piper Alpha became extremely productive. Soon, the operator Occidental sought permission to increase rates, and the decision was taken to do not just do gas treatment but also export. The gas plant was modified and the export began in 1978. [1,3] The Piper field exported 300,000 barrels a day via a pipeline to the Flotta terminal in the Orkney Islands and was at the heart of a complex of six producing fields, being the centre for oil and gas exports to the British mainland, accounted for about 12% of British production.