Baseline for Planning and Cost Estimation of Brazilian Decommissioning

Abstract

Decommissioning and abandonment of Brazilian offshore oil & gas fields has become more important in the last few years due to the maturing hydrocarbon producing basin in the region. However, a complete abandonment of a Brazilian offshore field has not been completed to date and the consequent lack of a reference case leads to uncertainties with operators and stakeholders during the conceptual phases of abandonment, when identifying the best decommissioning option and estimating a reasonable cost for the complete program of decommissioning activities. This paper aims to satisfy this uncertainty and develop a Brazilian baseline for front end planning and cost estimation of the decommissioning, removal and disposal options. The methodology presented in this paper is based on analysis of the national and international regulations applicable to decommissioning, the expectation of stakeholders and national supply chain benchmarking. Drawing on the conclusions of this analysis, the paper then presents the available decommissioning options generally applicable for fixed platform, floating platforms, pipelines and subsea facilities. The eligibility of each decommissioning option is then investigated against the background of current Brazilian regulatory requirement, highlighting those cases where the options are not mentioned in the legislation or where contradictions exist. Further analysis of the options is then undertaken to determine the preferred solution from the stakeholder perspective and to also define national supply chain benchmarking of the options to confirm whether the national supply chain can support the future potential demand for decommissioning in Brazil. Finally, the paper shows a comparative case study for the high-level planning and cost estimation for the decommissioning of a complex of small fixed platforms including the plugging and abandonment (P&A) of the platform wells.