The main objective of this paper is to provide an approach and valid mechanism for the decommissioning studies throughout the entire plant life cycle from Development Phase up to Asset end life. Decommissioning activities and related issues shall be considered from the early project phase in order to have a full knowledge of the criticalities and associated costs to be managed when the facilities will be decommissioned.
This approach can be applied to different types of Oil & Gas plants and involves several technical competencies with a dedicated process for On-shore and Off-shore assets covering all main phases of decommissioning process from the development steps up to the decommissioning execution. An appropriate implementation of this decommissioning approach is important to identify the best Decommissioning Option with lower Environmental Impact, provide Cost Estimates Study properly detailed, approvable, traceable, demonstrable and upgradable and practical solutions for optimizing activities duration and related costs. A Decommissioning Standardization with a consolidated process handbook can provide supportive guidance for the Decommissioning activities, thus falling within development and operational domain defining also dedicated level of decommissioning costs estimate accuracy during the asset lifecycle. Cost estimates prepared and periodically updated provide valuable contribution for field economics analysis. In this way, company is fully aware of all decommissioning issues from the early project stages till the Cessation of Production phase when decommissioning execution will start.
