不同因素对天然气水合物稳定带厚度的影响

天然气水合物在未来能源、自然环境和灾害等方面具有重要的研究意义，天然气水合物稳定带厚度用来表示水合物发育与分布的可能范围，与地温梯度、海水深度和海底温度等参数密切相关。根据Dickens和Quinby相平衡公式，定量计算了不同地温梯度、海水深度和海底温度参数下的水合物稳定带厚度。在保证其中2个参数不变的情况下，天然气水合物稳定带厚度随地温梯度增加而有规律的递减，随海水深度增加不断增加，随海底温度增加水合物稳定带厚度降低并且呈良好的线性关系。海底温度不变条件下，水合物稳定带厚度从地温梯度大、水深浅的区域，向地温梯JP2]度小、水深较深的区域不断增大。海底深度不变时，从地温梯度大、海底温度高的区域到地温梯度小、海底温度低的区域，水合物稳定带厚度不断增大。此外，讨论了基于Dickens和Quinby、Brown及Peltzer和Brewer等3种相平衡公式计算水合物稳定带厚度的差异，根据Dickens和Quinby相平衡公式计算的水合物稳定带厚度最大，其他相平衡公式计算的水合物稳定带厚度相对较小。

Different Factors on the Thickness of Gas Hydrate Stability Zone

Gas hydrate has important research significances in future energy, natural environment and disaster. The thickness of gas hydrate stability zone (GHSZ) shows the possible range of hydrate development and distribution. It is greatly related with geothermal gradient, sea bottom temperature and water depth. Based on hydrate phase equilibrium formula of Dickens and Quinby, we quantitatively calculated the thickness of GHSZ in different conditions of geothermal gradient, water depth and sea bottom temperature. When the two parameters in three parameters are assumed unchanged, the thickness of GHSZ decreases with the increase of geothermal gradient regularly, the thickness of GHSZ increase with water depth, and the thickness of GHSZ decrease with increasing of sea bottom temperature as a good liner relationship. If the temperature of the sea bottom is a constant, the thickness of GHSZ will increase gradually from the regions with the larger geothermal gradient and shallower water depth to the smaller geothermal gradient and deeper water depth. If the water depth is unchanged, the thickness of GHSZ will increase gradually from the region with the larger geothermal gradient and higher sea bottom temperature to the smaller geothermal gradient and lower temperature. In addition, we also discussed the differences among the three hydrate phase equilibrium formulas for calculating the thickness of GHSZ. The maximize result of GHSZ thickness was gotten by Dickens-Quinby′s phase equilibrium formula gets, and the smaller values was done by the two others.