Managing life extension process for safety critical elements on offshore oil and gas installations

Life extension (LE) of Safety Critical Elements (SCEs) is one of the hottest topics in the offshore Oil and Gas (O&G) industry today. Although LE is considered as the most appropriate alternative among the end of life management strategies (EOMLS), there are still several challenges confronting asset managers during LE phase of operation. Key among these challenges includes; lack of integrated technical and economic approach to assess the current health conditions of SCEs for LE, over reliance on expert knowledge and experience for selecting the most suitable LE strategy and the lack of suitable approach to integrate all LE decision making elements for effective operations of SCEs. To overcome these challenges, this research aimed at developing an integrated decision making framework to use for managing LE process for SCEs found on offshore O&G installations. In order to overcome the first challenge, a techno- economic framework which integrates technical and economic assessment procedures for condition assessment of SCEs is developed. Furthermore, approaches based on Life Cycle Cost Benefit (LCCB) concept and Multi Criteria Decision Making (MCDM) method are subsequently proposed to overcome the challenge of lack of suitable methodology for selecting the most appropriate LE strategy. Lastly, a proposed multi-stage remanufacturing architecture capable of integrating all LE decision making elements is developed. These decision making models have been developed and analysed using data from literature review, expert opinion, review of company internal documents as well as data from manufacturers of SCEs in the offshore O&G industry. The models are validated with a number of real life case studies which involves water deluge system, industrial air compressors and three phase separation systems to ascertain their efficacy. The outcome of validation processes indicates that these decision making models provide cost effective solutions to overcome the three key LE challenges outlined in this study. This research has added to the scientific understanding of this research area through creation of novel decision making models to support LE phase of operation in the offshore O&G industry.