Standards-Attributed Reuse–Retrofit–Replacement Method to Assess Offshore Platform Electrical Power Systems for Repurposing to LNG Regasification or CO2 Injection

Abstract

Repurposing aging offshore platforms into liquefied natural gas (LNG) regasification or CO2 injection facilities has been gaining attention as a viable alternative in the energy transition. However, a single systematic criterion for determining which equipment of the existing power system should be reused, retrofitted, or replaced is lacking. This study proposes a standards-attributed reuse–retrofit–replacement evaluation framework that utilizes provisions from established international standards and classification society regulations for ships and individual electrical equipment. Power system items are evaluated for functional adequacy, integrity, and regulatory compliance, then classified based on predefined decision rules. Item-level assessments are aggregated into a platform-level assessment (suitable, conditionally suitable, or not suitable) based on criticality tiers such as safety critical, operationally critical, and nonessential items. Criteria directly specified in the cited standards are distinguished from standard-based quantitative interpretations and from author-defined screening thresholds and decision rules; the quantitative interpretations are not themselves numerical limits directly prescribed by the cited standards, and the author-defined elements are not mandatory requirements of those standards. The operation of the framework is illustrated on a synthetic reference platform as a proof of concept, showing how the procedure yields differentiated reuse–retrofit–replacement (R–R–R) outcomes under the two conversion scenarios. The same power system was assessed as “conditionally suitable” and “not suitable” for LNG regasification and CO2 injection conversions, respectively. This variance stems from the different load requirements and risk characteristics, particularly the higher safety-critical auxiliary load associated with CO2 injection. Accordingly, the framework is intended as a screening and decision-support procedure that provides traceable rationale at the power-system level after high-level repurposing decisions; validation on actual platforms remains necessary before practical implementation.