Towards a Decision Tool for Decommissioning of Sub Sea Assets of Oil-Gas Platforms in Brazil

Abstract

This master thesis will offer an overview on the decommissioning process in Brazil. It will provide a created decision tool to find the best solution to know the most available decommissioning options to all subsea equipment which are mostly used for fixed oil gas platforms in Campos Basin. This tool has been created using the Multi Criterion Decision Analysis Method and it is prepared using the Microsoft Excel (64-bit). Decommissioning is the closure of fossil fuel drilling operations at an offshore platform and after the ending of the operations, rehabilitation of ocean and sea floor from the constructed condition to the pre lease circumstance. Oil crises in recent years and increasing global borrowings have increased the importance of oil gas platforms. With this increase, over 9,000 platforms were built. As a result of the changing of international and local legal basis and laws, abandoned platforms without take any precautions, at the ocean has been precluded. The oil companies were not doing the cleaning and recycling of the platforms that had been left out of operation because of the high costs and technological restrictions. In the wake of international laws, these companies are taking serious steps to remove platforms. In last few years decommissioning of offshore platforms in Brazil has become more importance. However, many factors should be taken into consideration during the decommissioning activities. These are various factors that are defined as socio-economic, technical, environmental, cost, restrictions on engineering work, safety measures. When these factors come together, the processes to be done become more complicated. At this point, we will develop a tool that will become a decision-making mechanism when the subsea assets of oil gas platforms are decommissioned, and will bring together all the factors considered above to make the best decision. All these factors will be analyzed for all subsea equipment using the weighting factor that is defined based on previous engineering works and expert opinions