Preliminary Concept Study: Selection of Optimal Lightweight Design Concept for Offshore Platform P&A

Abstract

As more facilities are nearing the end of their design life on the Norwegian Continental Shelf (NCS), the volume of costly plug and abandonment (P&A) operations is on the rise. Current practice is to use expensive drilling equipment for P&A. A lightweight, fit-for-purpose solution has been suggested to meet demands for cost-efficiency when performing P&A on offshore platforms. This thesis aims to choose an optimal concept for such a solution and investigate the feasibility of its development. A thorough investigation of current practices along with mapping the criteria of success for a new concept have been carried out. Using Analytical Hierarchy Process (AHP), a concept has been chosen from several alternatives. Additionally, wellbore data for the NCS has been analysed along with previous research to estimate the future P&A market potential. This thesis finds that there exists a large future market for P&A technology that can contribute to reducing costs. AHP analysis reveals that the novel Modular P&A Unit (MPU) concept described in this thesis should be developed further. A conceptual design for the MPU is presented.