Roostaei Morteza, Nouri Alireza, Fattahpour Vahidoddin, Chan Dave
Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Canada.
Pet Sci. 2017;14(4):731-745. doi: 10.1007/s12182-017-0194-x. Epub 2017 Nov 1.
In petroleum engineering, the transport phenomenon of proppants in a fracture caused by hydraulic fracturing is captured by hyperbolic partial differential equations (PDEs). The solution of this kind of PDEs may encounter smooth transitions, or there can be large gradients of the field variables. The numerical challenge posed in a shock situation is that high-order finite difference schemes lead to significant oscillations in the vicinity of shocks despite that such schemes result in higher accuracy in smooth regions. On the other hand, first-order methods provide monotonic solution convergences near the shocks, while giving poorer accuracy in the smooth regions. Accurate numerical simulation of such systems is a challenging task using conventional numerical methods. In this paper, we investigate several shock-capturing schemes. The competency of each scheme was tested against one-dimensional benchmark problems as well as published numerical experiments. The numerical results have shown good performance of high-resolution finite volume methods in capturing shocks by resolving discontinuities while maintaining accuracy in the smooth regions. These methods along with Godunov splitting are applied to model proppant transport in fractures. It is concluded that the proposed scheme produces non-oscillatory and accurate results in obtaining a solution for proppant transport problems.
在石油工程中,水力压裂导致支撑剂在裂缝中的输运现象由双曲型偏微分方程(PDEs)描述。这类偏微分方程的解可能会出现平滑过渡,或者场变量存在较大梯度。在激波情况下,数值计算面临的挑战在于,尽管高阶有限差分格式在平滑区域能提高精度,但在激波附近会导致显著振荡。另一方面,一阶方法在激波附近能提供单调的解收敛,而在平滑区域精度较差。使用传统数值方法对这类系统进行精确数值模拟是一项具有挑战性的任务。在本文中,我们研究了几种激波捕捉格式。每种格式的性能通过一维基准问题以及已发表的数值实验进行了测试。数值结果表明,高分辨率有限体积法在捕捉激波时通过解析不连续性表现出良好性能,同时在平滑区域保持精度。这些方法与戈东诺夫分裂法一起被应用于模拟支撑剂在裂缝中的输运。得出的结论是,所提出的格式在求解支撑剂输运问题时能产生无振荡且准确的结果。