Research progress on the exploitation of natural gas hydrate by thermal stimulation method

Natural gas hydrate is extremely high in exploitation value, and thermal stimulation method is one of the research emphases for the exploitation of natural gas hydrate. At present, the main heat injection modes of thermal stimulation method include thermal fluid injection, downhole resistance heating, microwave heating and solar heating. In this paper, the domestic and foreign research progress on the exploitation of natural gas hydrate by thermal stimulation method was overviewed, and the advantages and disadvantages of different types of heat injection modes were analyzed. The thermal fluid injection has the advantages of simple operation and fluid recycling, but its energy utilization rate is low, and it is applicable to exploit hydrate with higher saturation. Downhole resistance heating has less heat loss, and it is suitable for deeper exploitation wells. Microwave heating has high energy conversion rate and targeted heating effect on hydrates. And solar energy heating is clean and environmentally friendly, and it is in line with the strategic goal of sustainable development. Both microwave heating and solar energy heating have great development potentials and prospects, but their current technological development is not high enough to be popularized. The research results can be used as the reference for hydrate exploitation in the future. (1 Figure, 1 Table, 47 References)