The Study And Measurement Of Thermal Physical Properties Of THF Hydrate Bearing Sediment Under Normal Pressure

The development and utilization of natural gas hydrate has become the research focus of hydrate industry with the deterioration of the energy crisis in recent years. Natural gas hydrate as a potential clean energy source, achieving its commercial exploitation will have a significant impact for the future energy structure. Chinese scholars have proved reserve of natural gas hydrate resources in our country is very rich after continuously exploration and research. The development and utilization of natural gas hydrate resources is very important to our country's sustainable development strategy.The extraction process is easy to cause the landslides and other geological disasters because the hydrate reservoir is very sensitive to changes in temperature, so master the basic thermal physical property parameters of natural gas hydrate (NGH) has an important significance.Experimental design a set of small devices in order to study hydrates and hydrate sediment's thermal physical properties. Experiment with THF hydrate as the research object, through the transient plane heat source method to measure the thermal properties of dry quartz sand, water bearing quartz sand, ice bearing quartz sand, THF hydrate bearing quartz sand and ice or THF hydrate bearing natural sand. The extraction mainly studied the preparation method of the sample, measurement method of thermal physical property and thermal properties of hydrate bearing sediments.Come to a conclusion through the experiment research. Pressure and compression or not after THF hydrate formation has a little influence on thermal physical property of THF hydrate, and the heat capacity of THF hydrate close to heat capacity of ice. Thermal conductivity increase of THF hydrate with temperature rise that formation under the normal pressure at the temperature is between 250.15-268.15K,and conforms to the linear rule; thermal conductivity increase of THF hydrate with temperature rise at the temperature is between 268.15-277.55K, but it does not conform to the linear rule. The quartz sand particle size is smaller, the greater the coefficient of thermal conductivity, thermal diffusion coefficient and specific heat capacity of quartz sand with ice;the values drop of thermal conductivity and thermal diffusivity along with the rise of temperature, the values increase of specific heat along with the rise of temperature;. The quartz sand particle size is smaller, the greater the thermal conductivity of THF hydrates bearing quartz sand; the temperature dependence of thermal conductivity is related to particle size of quartz sand and the porosity of porous media, the values drop of thermal diffusivity along with the rise of temperature, the values increase of specific heat along with the rise of temperature. The thermal conductivity and specific heat increase of THF hydrate bearing natural sand along with the rise of temperature, thermal diffusivity drop along with the rise of temperature.