This paper discusses the added role of nextgeneration bioenergy systems in deep decarbonization in oil-dependent economies, focusing on energy economics, policy design and governance. This study investigates whether advanced bioenergy pathways (e.g. biofuels, biogas, bio-based chemicals and bioenergy with carbon capture and storage (BECCS)) can generate an economic impact with low emissions and alignment with the policy orientation given the structural dependence on fossil fuel revenues. The methodology is mixed methods using secondary data of energy and emissions databases from around the world, techno-economic and life cycle assessment evidence, and comparative policy analysis of petroleum-exporting and petroleum-dependent economies. The next-generation bioenergy systems can offer substantial lifecycle GHG reductions, improve energy system resilience, and enable economic diversification in the presence of coherent pricing, subsidy reform, and carbon governance frameworks, concludes the key findings. Nevertheless, binding constraints include weak institutions, land-use risk, and policy incoherence. The analysis finds that advances in bioenergy will solely decarbonising petroleum-rich economies with concurrent reforms in energy markets, climate governance, and green finance. Phase policy sequencing, sustainable feedstock system investment, and bioenergy deployment alignment with petroleum-sector transition strategies are recommended. The document adds to what is known by redefining bioenergies, not just as a renewable alternative, but as a tool enabling structural transitions within oil economy and policy discussions.