Decommissioning of Offshore Oil and Gas Installations in Campos Basin - Brazil: Main Challenges and Achievements

Abstract The article provides an overview of the challenging scenario associated with decommissioning projects in Campos Basin. The challenges are associated with the variety of structures to be decommissioned, the diversity and sensitivity of the environment in the region, and the incipient and still evolving decommissioning regulations in Brazil. A particular focus goes to the decommissioning of nine Marlim Field platforms (five Floating, Production, Storage and Offloading – FPSO and four semi-submersibles – SS, at depths from 160 to 1000 m), their interface with the field revitalization project, its complex environmental scenario (due to the occurrence of deepwater coral formations), and the development of optimized solutions, such as the pull-out of risers by cutting them above sea water level, inside the FPSO internal turret, which eliminated the need for diving and reduced around 50% the cost of operations, through the reduction of PLSV demand. In terms of increasing the sustainability of decommissioning projects, several measures are presented, including the reuse of flexible pipelines from the decommissioning project of FPSO Capixaba (Jubarte Field), which resulted in more than 50 km of lines (36% of the total scope of the project) being used in another project. It also addresses the lessons from dismantling the P-32, the first sustainable recycling project for FPSO executed in Brazil. Brazil has consolidated itself as the third-largest decommissioning market in the world, mainly due to the projects in Campos Basin. Only in the Marlim Field, besides its nine platforms, more than 300 risers, 1200 km of flexible lines, 225 km of rigid pipelines, and eight large equipment (e.g.: manifolds) will be decommissioned by 2030. Therefore, this article discusses in detail these projects (lessons learned and innovations) and their great potential to contribute to improving the decommissioning world industry.