Objective Offshore oil and gas production suffers from high carbon intensity and low energy efficiency. Meanwhile, marine renewable developments in deep and far seas are hindered by high capital costs and power accommodation limits. This study therefore explores engineering modes for multi-energy complementary integration between marine renewables and oil & gas systems. It aims to provide technical pathways and practical references for the green and low-carbon transition of marine energy.

Methods Rooted in national energy policies and local marine resource endowments, this paper systematically reviews the state of integrated marine renewable and oil & gas development. It further identifies major industrial barriers covering hardware equipment, grid stability, commercial mechanisms and resource coordination. A cross-dimensional comparison is then conducted from technical principles, equipment architectures, application scenarios, economic performance and operation & maintenance perspectives.

Results Six core engineering modes are defined and examined in this work. These schemes cover fixed offshore wind integration, semi-submersible floating wind integration, tension-leg floating wind integration, ocean thermal-geothermal coupling, multi-energy retrofitting of decommissioned platforms, and offshore renewable power-computing synergy linked to oil and gas operations. These modes fully cover nearshore and deep-and-far-sea scenarios for offshore oil and gas development. Engineering practices have validated the feasibility and technical advantages of these multi-energy integration schemes. Priority shall be placed on technically proven, cost-effective options. Representative examples include nearshore fixed offshore wind integration and deep-and-far-sea semi-submersible floating wind integration. Existing assets within oil and gas development zones can be reused to deploy large-scale green power substitution schemes. Such projects cut operational carbon emissions during hydrocarbon production and support the rollout of multiple green oilfield demonstration sites. Continuous upgrades of large-megawatt tension-leg floating wind technology will facilitate the construction of large-capacity multi-energy complementary demonstration bases tailored for deep and far seas.

Conclusion Integrating marine renewables with oil & gas assets represents a critical pathway toward the green low-carbon transition of marine energy. This integration substantially curbs carbon emissions from offshore field operations and improves the economic competitiveness of marine renewable projects. Future research should prioritize breakthroughs in core technologies, refine policy and standard frameworks, and accelerate large-scale demonstration deployments.