Effect of Temperature Gradient on Process of Methane Hydrate Formation-dissociation and Its Resistivity Changes in Coarse Sand
温度梯度对粗砂中甲烷水合物形成和分解过程的影响及电阻率响应

It is important for methane hydrate exploration in the permafrost region to evaluate the resistivity changes during the process of methane hydrate formation and decomposition of gas hydrate.In this paper,we use the devices of frozen phase transition temperature and resistivity distribution which are self designed to elucidate the methane hydrate formation and decomposition process in the coarse sand.The experimental results show that the processes of hydrate nucleation,formation,aggregation and decomposition can be detected accurately and efficiently by the experimental devices.The differences temperature gradients obviously influence the formation and distribution of the methane hydrate in the coarse sand.With increase of temperature gradient,the distribution of the methane hydrate becomes uneven.The methane hydrate is aggregated more easily at the apex of high-temperature while the time interval of the hydrate aggregation is shorter.The resistivity of the samples increased with increase of hydrate saturation.