With rapid depletion of conventional energy resources and the promotion of low-carbon energy development, natural gas hydrate (methane hydrate) has been attracting increasing attention over the governments, scientists, and industries, for its huge reserves and less environmental pollution after combustion. Japan and China have successfully conducted trail production and harvested natural gas from marine hydrate reservoir, which ignites the hope of commercial natural gas production by natural gas hydrate exploitation. However, natural gas was buried in the sediment under the deep ocean sea floor, and gas hydrate serves as effective cementing agent among the sediment particles. Drilling production well and gas production from hydrate reservoir may result in a series of natural geological hazards. Methane leakage from the hydrate reservoir and the migration of methane into the overlying water column can cause ocean acidification. Furthermore, once abundant methane bubbles escaped into the atmosphere will influence the carbon cycle and global climate change. Quantitative research of environmental and ecosystem impact of methane leakage from natural gas hydrate exploitation is indispensable for promoting the commercial exploitation process of natural gas hydrate. This paper outlines the potential environmental impact of natural gas exploitation in detail, which provides references for future natural gas hydrate exploitation and utilization.
Keywords natural gas hydrate, clean energy, methane seepage, environment impact, marine ecosystem