In order to reduce the energy consumption associated with produced-fluid heating and treatment in oil production and gathering processes and to satisfy the thermal load demand of the wellhead-to-station gathering and transportation process, a multi-energy complementary heating scheme based on solar energy, geothermal energy, and recoverable waste heat from produced fluids, together with a dynamic simulation model, was used to investigate the thermal balance characteristics and energy performance of the system under different seasonal operating conditions, considering the solar and geothermal resource conditions in the Daqing Oilfield area and the waste-heat recovery potential of produced fluids from high-water-cut oil wells. The results show that the system can maintain dynamic thermal equilibrium during long-term operation; the average coefficients of performance (COP) of both the ground-source heat pump and the waste-heat heat pump are higher than 4.90, indicating stable heating performance; the annual solar heat supply accounts for approximately 37.30% of the total heating demand at the wellhead, effectively reducing the conventional heating load; and the temperature of the gathering and transportation medium remains above the crude-oil pour point along the pipeline throughout the entire operating cycle, thereby satisfying the requirement for safe gathering and transportation. It is concluded that the proposed system can provide a reference for the design and low-carbon operation optimization of multi-energy complementary heating systems in oilfield gathering and transportation processes.