论文标题
分析从甲烷水合物中的气体产生以及使用同轴井眼的热刺激时相关的热量和传质的研究
Analytical investigation of gas production from methane hydrates and the associated heat and mass transfer upon thermal stimulation employing a coaxial wellbore
论文作者
论文摘要
在这项研究中，已经开发了一种径向2D分析方法，以融入储层中的井眼加热过程和相关的甲烷水合物解离。假定同时考虑传导和对流热传输的热源。它由内管和外壳，砾石和水泥层的外部结构组成。在储层中，采用分隔离解和未分离的区域的移动边界的相似解决方案用于构建分析解决方案。已经研究了两种不同的水源操作方案：i）内管。 ii）来自Wellbore的环形部分。考虑到各种初始和边界条件以及储层特性的储层中的温度分布，水库中的温度和压力分布，水合离解速率以及能效。这两个不同的操作方案的结果几乎具有相同的结果，而在热水进入环的情况下，气体产生略高，这是与储层直接接触的。增加入口水温或降低井眼压力会增加气体产量。同时应用它们会导致更大的气体产生和能源效率。储层的某些特性，例如孔隙率，热扩散率，导热率和储层厚度，与解离速率直接相关，但是储层的渗透性和气体粘度几乎对这一过程没有影响。井眼参数，例如热水，入口温度和井眼半径之类的流量，除了内管半径外，对井眼的平均温度有直接影响，以及离解过程中的相关结果。
In this study, a radial 2D analytical approach has been developed to couple the wellbore heating process and the associated methane hydrate dissociation in the reservoir. A coaxial wellbore is assumed as the heat source where both conduction and convection heat transfers are considered. It consists of an inner tube and an outer structure of casing, gravel, and cement layers. In the reservoir, a similarity solution employing a moving boundary separating the dissociated and undissociated zones is employed to build the analytical solution. Two different operating schemes for water supply into wellbore heat source have been studied: i) from the inner tube; and ii) from the annulus section of the wellbore. Temperature distribution along the wellbore, temperature and pressure distributions in the reservoir, hydrate dissociation rate, and energy efficiency considering various initial and boundary conditions and reservoir properties are evaluated. The two different operating schemes have almost the same results with slightly higher gas production in the case of hot water entry into annulus, which is in direct contact with the reservoir. Increasing the inlet water temperature or decreasing the wellbore pressure increases gas production. Applying them simultaneously results in a greater gas production and energy efficiency. Some of the reservoir's properties, such as porosity, thermal diffusivity, thermal conductivity, and reservoir thickness, have direct relation with the dissociation rate, but the reservoir's permeability and gas viscosity have almost no impact on the process. The wellbore parameters, such as flow rate of hot water, inlet temperature, and wellbore radius except the inner tube radius, have direct impact on the wellbore mean temperature and the associated results in the dissociation process.
