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• Hydrate decomposition was enhanced by circulating warm water from the deep gas layer. • Increasing the flow rate of the circulating water improved the production efficiency. • A cycling regulation of the hybrid water flow rate could enhance the EER by 16.23 %. Utilizing the geothermal energy from the deep gas layer to enhance the hydrate decomposition is a potential clean production approach, avoiding the vast costs and severe pollution in the traditional heat injection scheme. In this work, a novel method was proposed to promote hydrate decomposition by employing circulating water to transport heat from the deep gas layer. Results showed that increasing the water flow rate from 9.82 mL/min to 39.28 mL/min could significantly improve the production efficiency by 27.27 %. Yet, the energy efficiency ratio (EER) slightly decreased by 3.31 % due to the increased power consumption of the water pump. A hybrid water flow rate was thus used with a lower rate in the later production stage when the heat absorption of hydrate decomposition was declining accordingly. This was found to successively improve the EER by 2.68 % while maintaining comparable production efficiency; a further cycling regulation (intermittent circulating) of the hybrid water flow rate could significantly enhance the EER by 16.23 %. The results could guide the efficient utilization of natural geothermal energy to facilitate the large-scale gas production from the natural gas hydrates when heat supply from the surrounding sediments was limited. [ABSTRACT FROM AUTHOR]