Realizing Net Zero Carbon Emissions for Sustainability of Existing and Aging Offshore Facilities
Authors: Chan Yen Pinng , Muhammad Yasin Muhammad Yazuwan Sallij Bin , Muhamad Ir. Suhana Binti 
Published: October 2022

Abstract
Amidst global push towards sustainable future, efforts to drive down greenhouse gas (GHG) emissions towards net zero across all upstream assets and new developments are expected to intensify. This task has proven to be far more challenging for existing, aging offshore facilities both technically and commercially.
This paper will share various fit-for-purpose options identified through rigorous front-end loading (FEL) processes which can be implemented on existing, aging facilities to accelerate and realize sustainable GHG emissions reduction efforts across all business value chain.
Essence of decarbonization is in the reduction of major hydrocarbon emissions. Apart from carbon tax inclusion, proactive directives in zero continuous hydrocarbon venting and flaring in upstream facilities while maximizing renewable energy applications has already set the momentum. Existing, aging facilities are in dire need of similar sustainable carbon abatement strategies.
Supported with introduction of a basic yardstick for techno-commercial assessment, up to 8 concepts were explored through feasibility study at FEL assessing the extent of brownfield modification, emissions reduction efficiency and associated costs for carbon abatement at legacy facilities. Concepts range from cost-efficient facilities conversions to CAPEX-intensive gas injection and sequestration solutions. Options with monetization potential such as gas export, floating compressed natural gas (FCNG), condensate recovery system (CRS) and gas liquefaction are within consideration as well.
Value improvement beyond facilities design life is influenced by sustainability of solutions introduced. Legacy facilities commonly adopt conventional process design that lean towards venting and flaring, with generally limited flexibility in design improvement. Efforts in emissions reduction is therefore deemed most suitably carried out in both a short- and long-term manner, which is replicable regardless of a facility's age.
Short term solution of converting existing vent stacks into flare stacks is projected to be able to significantly reduce GHG emissions up to 70% in the span of 3 years. For monetization opportunities such as pipeline export, CNG, CRS and liquefaction, area development strategy is recommended to establish economy of scale. Leading towards net zero goals, long-term efforts through gas injection and sequestration will be more sustainable as they demonstrate potential of up to 95% GHG emissions reduction within field life. Carbon abatement strategies for existing facilities can be formulated through a weighted-scoring process, guided with a basic yardstick for high level assessment. Ability to synergize carbon abatement with capital projects innovatively to achieve positive economic returns while transitioning into a global environment of sustainability is crucial.
Decarbonization efforts especially for existing, aging upstream facilities requires firstly, a strong managerial aspiration in the sustainability agenda; Secondly, expertise of operations to balance life cycle costs against carbon abatement investments. Strategies outlined in this paper share insights on how decarbonization efforts can be streamlined for effective execution towards net zero carbon emissions targets.