论文标题
用于模拟具有河流沉积结构的异质储层中的二氧化碳毛细管捕获的有效构成关系
Effective Constitutive Relations for Simulating CO2 Capillary Trapping in Heterogeneous Reservoirs with Fluvial Sedimentary Architecture
论文作者
论文摘要
二氧化碳（CO2）储存库通常表现出反映河流沉积的沉积结构。由这种结构引起的岩石物理特性的异质性会影响注射二氧化碳的动力学。我们先前使用了一种地理模型方法来表示这种异质性，包括本构饱和关系中的异质性。在注射期间和注射后研究了河流储层中二氧化碳的动力学。结果表明，小规模（厘米至米）的特征在毛细管捕获过程中起着至关重要的作用，并且对二氧化碳的物理和溶解捕获以及储层中二氧化碳的最终分布产生了主要作用。饱和功能的异质性在该小尺度上起作用增强了毛细管捕获（捕获），创建毛细管固定并增加羽流的表面积。在这里，对这些小规模的捕获过程的理解被用来建立有效的饱和关系，以较大规模地表示这些过程的整体效果。 While it is generally not computationally feasible to represent the small-scale heterogeneity directly in a typical reservoir simulation, the effective saturation relationships for capillary pressure and relative permeability presented here, along with an effective intrinsic permeability, allow better representation of the total physical trapping at the scale of larger model grid cells, as typically used in reservoir simulations, and thus the approach diminishes limits on cell size and decreases simulation储层模拟的时间。
Carbon dioxide (CO2) storage reservoirs commonly exhibit sedimentary architecture that reflects fluvial deposition. The heterogeneity in petrophysical properties arising from this architecture influences the dynamics of injected CO2. We previously used a geocellular modeling approach to represent this heterogeneity, including heterogeneity in constitutive saturation relationships. The dynamics of CO2 plumes in fluvial reservoirs was investigated during and after injection. It was shown that small-scale (centimeter to meter) features play a critical role in capillary trapping processes and have a primary effect on physical- and dissolution-trapping of CO2, and on the ultimate distribution of CO2 in the reservoir. Heterogeneity in saturation functions at that small scale enhances capillary trapping (snap off), creates capillary pinning, and increases the surface area of the plume. The understanding of these small-scale trapping processes from previous work is here used to develop effective saturation relationships that represent, at a larger scale, the integral effect of these processes. While it is generally not computationally feasible to represent the small-scale heterogeneity directly in a typical reservoir simulation, the effective saturation relationships for capillary pressure and relative permeability presented here, along with an effective intrinsic permeability, allow better representation of the total physical trapping at the scale of larger model grid cells, as typically used in reservoir simulations, and thus the approach diminishes limits on cell size and decreases simulation time in reservoir simulations.
