Decommissioning strategies for fixed offshore platforms in Brazil

Abstract

In the early 1970s, consumption of petroleum products in Brazil doubled. With that, was great the need the discoveries of new wells. The possibilities for expanding production were at sea, which began to receive even more attention. After the discovery of the first offshore field, in Sergipe, Petrobras made more than 20 discoveries on the coast of several states. It was the beginning of a new era. In 1977, the Campos Basin, located between the states of Espírito Santo and Rio de Janeiro, began its commercial offshore production, becoming the most important oil province in Brazil until the discovery of the Pre-Salt province, in the Santos Basin. As these fields are producing for a long time, many of them are already completely depleted or their production is in way of to be not commercial anymore, and their facilities need to be decommissioned. This review of decommissioning practices of fixed offshore platforms carried out worldwide has focus on the removal of topside with special vessels designed for this purpose or with conventional methods (crane vessels + barge). It will show the benefits of using specialised heavy lift vessels to remove the topsides and move it to shore for dismantling / recycling / reuse / disposal. The cases for study were the successful decommissioning projects in the North Sea: Brent B/D, Valhall QP, Viking, Curlew, Eider A, Golden Eye and Leman, Iwaki-Oki, Halfweg Q1, Yme and Ninian North.

DOI:https://doi.org/10.56238/uniknowindevolp-012