Abstract: To further address the industry challenges of low efficiency, high energy consumption and emissions, and high drilling operation cost of conventional rig power systems, and meet the development requirements of green and low-carbon drilling under the “Dual Carbon” strategy, this paper investigates the key technologies and engineering applications of oil-electric hybrid drilling rigs. By integrating key technologies including grid connection of small DC generator sets, joint driving of permanent magnet motors, battery energy storage peak shaving and EMS comprehensive energy management, a novel power drive system for oil-electric hybrid drilling rigs is developed, realizing the new-energy power reconstruction of core equipment such as drawworks, rotary tables and mud pumps. Field application results show that compared with traditional mechanical drilling rigs, this rig reduces diesel consumption by more than 25%, cuts carbon emissions by 20%～30%, and raises the load rate of generator sets to over 75%. It also features power redundancy, convenient operation, environmental protection and energy saving, which effectively lowers drilling operation costs and improves the economy, reliability and advancement of the rig power system. The research findings provide a practical technical scheme for energy-saving upgrading and green transformation of petroleum rig power systems, and possess important engineering promotion value.