No abstract

Amid 2020 challenging business environments due to COVID-19 pandemic and strong global push towards transition to cleaner energy, PETRONAS has declared its' aspiration to achieve net zero carbon emissions by 2050. PETRONAS sustainability journey has begun for more than two decades and with strong management support towards renewable and as part of PETRONAS's technology agenda, its' research arm, PETRONAS Research Sdn. Bhd. (PRSB) has been working on ways to use renewable energy sources for offshore oil and gas platforms in Malaysia. Oil and Gas industry has long relied on turbine generators for offshore power generation. These turbo-fired machineries are operating as microgrid with existing power management system (PMS) as microgrid controllers. They normally use either gas or diesel as fuel gas to ensure reliable power generation where high maintence cost is expected to operate these generators. Also, they have low energy efficiency and hence, usually oversized to ensure meeting the demand reliably. Typically, the power generation load is being taken by two units of turbine generators with another unit as spare. This has resulted in high operational expenditure (OPEX) and contributes to high levelized cost of energy (LCOE) for offshore power generation for such conventional system. LCOE is the yardstick for power generation technology, and it measures discounted lifecycle cost consisting of both capital expenditure (CAPEX) and OPEX, divided by discounted lifecycle of annual energy production [2], [4], [5]. Also, these turbine generators operating at platforms that have gas evacuation pipelines will use up precious fuel gas which can otherwise be sold. This will have impact on the total sales gas revenue. Not withstanding, the burning of the fuel gas will result in the emissions of carbon dioxide (CO2) and hence is exposed to carbon tax. To mitigate this issue, PRSB has developed an offshore hybrid power generation concept to leverage and optimize wind turbine system for offshore power generation in weak wind area such as Malaysia. In this concept, one gas turbine generator is replaced by an offshore wind turbine adapted to low wind speed region. This will lower the maintenance cost and carbon exposure. Also, the fuel gas will be diverted to sales gas. This in turn will improve the economics of the renewable solution thereby making offshore renewable power generation feasible for oil and gas platforms. Forward thinking efforts include pushing the limits of harnessing wind energy in weak wind area such as Malaysia. In here, considerations of a total solution include not only the type of wind turbine generator that can be adapted to weak wind area and having the lowest maintenance requirements as possible, but also looking into cutting edge foundation technologies. The LCOE is expected to be lower than conventional power generation. To ensure optimized hybrid concept, careful selection and adaptations of wind turbine system and its' substructure are required to achieve a cost-effective solution [3], [2]. Conceptual engineering and front-end engineering design were conducted which resulted in the development of the hybrid offshore power generation system. In this paper, the hybrid concept will be shown, the considerations for selection of a suitable wind turbine will be shared and the decisions leading the to the selection and optimization of the foundation type, either fixed bottom or floating are elaborated.

In this study, the viability of harnessing wind energy for offshore oil and gas (O&G) platforms as a micro-grid solution in low wind speed regions to power O&G platforms is explored. However, wind, as a renewable energy, is known to be highly variable and is unable to provide standalone power reliably within a micro-grid solution due to the variation of the wind speed at hub height, which subsequently leads to a variation of the power outcome. Here, a hybrid power generation concept is developed in which one gas turbine generator (GTG) is replaced with a floating horizontal axis wind turbine (WT) system. By setting up this system, the reduction of the maintenance costs of the GTGs and the reduction of fuel gas consumption reduces carbon dioxide (CO2) emissions. In addition to this, the fuel gas savings in terms of the business side of such a solution provide a positive revenue impact. In this feasibility study, a technical framework is developed, followed by an economic framework. In the technical framework, wind assessments are performed to obtain the annual energy production for the selected field. Furthermore, an economic framework is established for both conventional and hybrid concepts in two scenarios: greenfield and brownfield, where the incremental net present value (NPV) and levelized cost of energy are calculated. The resultant difference in NPV for hybrid power generation compared to conventional power generation was found to be between 22% and 37%. The levelized cost of energy (LCOE) for WT is USD 165.52/MWh, which is 39% lower than for conventional, gas turbine-only operations. The LCOE for the hybrid approach is lower than for the conventional scenario by 22%. In conclusion, the hybrid micro-grid concept solution can harness wind energy from low wind regions with better economic benefits compared to conventional methods through the proper selection of the WT system, its floating substructure, and efficient micro-grid system for powering oil and gas platforms.