When Girassol entered production in 2001, five short years after its discovery, it was the largest ever deep offshore project in 1400m of water. At this depth, the extraction of oil from the seabed and its transportation to the FPSO necessitated the development of brand new technology, known as riser towers, which ties in an isolated bundle, 1250m long rigid pipes with an overall diameter of 1.5m.
When Dália entered production, a new concept had to be developed to cope with the additional need for thermal isolation that resulted in flexible risers, some 1650m in length and weighing almost 800 tonnes. With a record breaking outer diameter of 60cm these flexible risers are made up of no less than 11 layers of thermal isolation materials, designed to guarantee that fluids can circulate, provide insulation, and ensure the device’s mechanical resistance.
The most outstanding innovation is the inclusion of a gas lift system made up of 24 lines that feed 6 injection points at the foot of the riser, for a total daily injection capacity of 800,000m3 of gas. The group is continuing its innovative research in order to connect the FPSO Girassol to increasingly distant oil fields – Jasmim, 5km away, and then Rosa, almost 15km away.
With this purpose, the FPSO is fitted with over 5,600 tonnes of extra equipment and facilities, including two large modules… all without interrupting production!
This drive received official recognition in Dubai in 2007, when Total won the International Petroleum Technology Conference prize.
*Source: historical publication “Pioneers in 1953, Leader in 2013” (March 2014).