China National Offshore Oil Corporation (CNOOC) has reported that its offshore heavy oil thermal recovery technology system and supporting equipment have reached large-scale deployment, with cumulative recovery surpassing 5 million metric tons. This establishes China as the first nation to achieve industrial-scale offshore heavy oil thermal recovery.

Heavy oil, characterized by high viscosity, density, and poor flow, has long posed significant extraction challenges. Offshore recovery adds further complexity due to limited platform space and high operational costs, making the accomplishment a breakthrough in both engineering and economic terms.

Globally, about 70 percent of remaining oil resources are heavy oil, making it a central focus for production growth. China ranks among the world's top four heavy oil producers, with more than 600 million tons of offshore high-viscosity reserves requiring thermal injection, representing about one-fifth of its national heavy oil resources.

According to CNOOC, sustained development of these reserves is vital to strengthening domestic oil and gas output. In 2025 alone, thermal recovery production exceeded 1.3 million tons, with annual production expected to reach 2 million tons by year-end.