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沉积物与流体流动的性质是影响水合物形成和聚集的两个重要因素,为研究水合物在沉积地层中的赋存机制必须探明高压环境下含水合物沉积物在非饱和渗流条件下的相互影响关系。以逸度差为水合物反应驱动力,反应动力学常数为Arrhenius类型,建立了包括非饱和流体流动-沉积物特征-水合物形成动力学耦合的二维模型,从理论上研究了多孔介质内流体与沉积物参数如含水率、去饱和系数、水力分布和水合物饱和度等在孔隙内的相互影响规律。结果表明,在设定的条件下,随着反应的进行孔隙水压力随时间逐渐大,在相同条件下水合物饱和度与温度增加导致孔隙水压力变大,其中水合物饱和度的影响较小,而沉积物基质吸力、去饱和系数与本征动力学常数则与孔隙水压力成反向变化,其中本征动力学常数的影响较大。
The nature of sediment and fluid flow are two important factors that affect the formation and accumulation of hydrates. To study the mechanism of hydrate formation in sedimentary formations, it is necessary to find out whether the hydrate-bearing sediments under high pressure conditions are under unsaturated seepage conditions Interactions. Taking the fugacity difference as the driving force of hydrate reaction and the reaction kinetic constant as Arrhenius type, a two-dimensional model including the formation of fluid-sediment features-hydrate formation in unsaturated fluid was established. Fluid and sediment parameters such as moisture content, desaturation coefficient, hydraulic distribution and hydrate saturation in the pore interaction law. The results show that under the set conditions, the pore water pressure gradually increases with time as the reaction progresses. Under the same conditions, the increase of hydrate saturation and temperature leads to the increase of pore water pressure. The effect of hydrate saturation is smaller , While the sediment substrate suction, desaturation coefficient and intrinsic kinetic constant are inversely proportional to the pore water pressure, of which intrinsic kinetic constants have a greater influence.