Bonga Main Life Extension Project: An In-Situ Life Extension of an FPSO Using FAIR+ER Methodology and Digital Twin Technology as Basis for Scope Identification and Definition

Abstract Production commenced in 2005 from the Bonga Main Field, which is a Floating Production Storage and Offloading (FPSO) + subsea development situated in between 950-1500m of water depth and about 120km offshore Lagos Nigeria. The Bonga FPSO has a nominal 20-year design life and at the time it was commissioned and till date, remains the largest FPSO in Nigerian waters with a nameplate capacity of 2,000,000Bpd, production handling capacity of 225,000Bpd and export capacity of 1,000,000Bpd through a single point mooring (SPM) buoy system. By January 2014, the Bonga Field had produced its FID promised volume of 500 million Barrels, and by February 2023 had produced 1 billion barrels. The Bonga Main Life Extension (BMLE) Project aims to extend the life of the FPSO by additional 15 years to produce the tail volumes from the field in addition to infill volumes from further developments including the Bonga North tie-back project. To assess the requirements to extend the life of the FPSO, a well-established process known as the Focused Asset Integrity Review (FAIR) + Equipment Review (ER) Life-Extension process which brings global performance standards into the evaluation of Safety critical elements (SCE) was used to identify status and to determine required actions for life extension of the FPSO. While the initial FAIR+ER LE, Corrective Actions Workshop & Scope challenge was carried out in between October 2016 and February 2016, it was repeated between November 2019 and April 2020 and this resulted in identification of 34 sub-project scopes across Topsides, Subsea, OHRM and pipelines. Each sub-project has pre-defined trigger points which are compared with the outcomes of relevant studies and/or inspections to determine if they should be matured to execution. Further to the aforementioned, the decision for an in-situ life extension rather than dry docking was chosen after a concept selection for a 10-year life extension period. As of December 2023 a 15-year life extension was firm for Bonga FPSO based upon the outcome of analysis of the state of integrity of the FPSO Hull, using a Digital Twin Technology while working with Vendors. This study outcome was subjected to further reviews and challenge to check it for credibility and robustness, prior to support for 15-year life extension. This paper aims to provide an overview of BMLE portfolio, scope development and maturation process, project philosophy and governance, key challenges encountered on the project, the assessment to determine the remaining Hull life and current project status. This paper is part of a Deep-water Projects Nigeria presentation under the growth theme for OTC 2024, and the other papers are listed in the references.