Integrated, scalable MBS for flow through porous media

流体在多孔材料中的流动对于理解和预测各种功能和规模的系统的行为至关重要，这些系统包括碳氢化合物储藏层、含水层、分离塔和带有填充床、过滤器、膜分离器甚至催化转化器的反应器单元。近年来，为了改善油藏管理，人们迫切希望在油藏模拟中融入更多的物理知识，并呼吁通过使用高性能计算(HPC)来大幅提高计算能力。随着石油和天然气价格在一年内从过去20年的最低水平波动到最高水平，这一需求变得尤为关键。这个项目的目标是开发一个综合的模拟器，用来模拟非均质多孔材料的流动。目前的方法是使用具有单一物理尺度的模拟。然而，最近在高性能计算方面的进展使得显著增加问题的规模和使用更复杂的方法成为可能。挑战是将单个模拟合并成一个综合的多尺度系统，该系统将能够包括所有物理尺度，并将根据输入数据进行自我调整。重点将放在最终产品的便携性、可伸缩性、效率和可扩展性上。建议的模拟器将是一种改进的油气藏管理预测工具，一旦可用，将准备在集成网格架构上使用。渗流在多孔介质中是一个多尺度现象。基于格子Boltzmann方法的微观尺度模拟将用于直接模拟多孔材料中的流动。利用LatticeBoltzmann方法的灵活性，岩石样品的显微层析数字图像将被用来逼真地表示受流动影响的空间域。在细观尺度上，采用随机方法对岩石结构的微观特征对流场的影响进行系统的隔离和研究。这种碎裂方法也将被用来开发一种岩石性质表征的方法。基于常规有限差分方法的宏观模拟将被用来检验修正后的流动模型对油藏规模油气产量的影响。宏观模拟将包括生产/注水井(在油藏模型中形成奇点)在油藏生命周期内的动态。它还将把渗流与地质力学(取决于孔隙度的渗透率和非达西系数)的耦合结合起来。这项研究将：(I)提高我们对基本渗流机制的理解；(Ii)更新各向异性多孔材料中非达西渗流的模型；(Iii)在模拟中考虑不连续面的存在，如井和裂缝。拟议研究的创新包括：(A)使用不同尺度的最先进的模拟；(B)使用实验测量的量来推断多孔介质的性质并更新流动模型；(C)将一套原型软件的单个组件集成到用于工业用途的无损模拟器中；以及(D)应用共享内存和分布式并行的混合应用，以在各种HPC架构上实现可伸缩性。这项研究项目对研究生的教育经验将是非常有价值的。它的教育方面还将涉及将高性能计算应用纳入三个系的本科课程，并为本科生开发研究经验研究项目。因此，它将使我国的一大批技术人员掌握高性能计算应用程序的有用方面，并与高性能计算基础设施进行互动。

Fluid flow through porous materials is critical for understanding and predicting the behavior of systems as diverse in function and scale as hydrocarbon reservoirs, aquifers, separation tower andreactor units with packed beds, filters, membrane separators and even catalytic converters. Recently, there has been a thrust to incorporate more physics in reservoir simulations, as well as acall for substantial improvements in computational capability through the use of High Performance Computing (HPC), in order to improve reservoir management. This need hasbecome particularly critical as oil and gas prices have fluctuated within one year from the lowestlevel of the past two decades to the highest. The goal of this project is to develop an integratedsimulator for flow through heterogeneous porous materials using a hierarchy of simulations.Current approaches involve the use of simulations having a single physical scale. However,recent advances in HPC have made it possible to increase significantly the problem size and touse more sophisticated approaches. The challenge is to combine the individual simulations into anintegrated multiscale system that will be able to include all physical scales and will self-adjust inaccordance with the input data. Emphasis will be placed on the portability, scalability, efficiencyand extensibility of the final product. The proposed simulator will be an improved prediction toolfor hydrocarbon reservoir management and will be ready for use on integrated grid architectures,as they become available.Flow through porous media is a multi-scale phenomenon. Microscopic scale simulation, based onLattice Boltzmann Methods, will be used for the direct simulation of flow through porous materials. Microtomographic digital images of rock samples will be used to realisticallyrepresent the spatial domain subjected to flow, taking advantage of the flexibility of LatticeBoltzmann Methods. At the mesoscopic scale, stochastic methods will be used for the systematicisolation and study of the effects of microscopic features of rock structure on the flow field. Thestochastic approach will also be used to develop a method for rock property characterization. Amacroscopic simulation, based on conventional finite difference methods, will be used to test theimpact of modified flow models on hydrocarbon production at reservoir scale. The macroscopicsimulation will incorporate the behavior of production/injection wells (which form singularities ina reservoir model) over the life of a reservoir. It will also incorporate coupling of flow withgeomechanics (porosity-dependent permeability and non-Darcy coefficients). The educationeffort resulting from this project will emphasize the training of undergraduate students in the useof HPC resources.This research will: (i) improve our understanding of the fundamental flow mechanisms;(ii) update the model for non-Darcy flow through anisotropic porous materials; and (iii) integratethe presence of discontinuities, such as wells and fractures, in the simulation. The innovations ofthe proposed study include: (a) use of state-of-the-art simulations at different scales; (b) use ofexperimentally measured quantities to deduce the properties of the porous medium and to updateflow models; (c) integration of the individual components of a set of prototype software into aseamless simulator for industrial use; and (d) application of a hybrid of shared-memory anddistributed parallelism to achieve scalability on a variety of HPC architectures. The research project will be extremely valuable for the educational experience of the graduate students involved. Its educational aspect will also involve the incorporation of HPC applications in the undergraduate curricula of three Departments and the development of research projects for Research Experience for Undergraduates. It will, thus, prepare a large group of the technical workforce of our State to the useful aspects of HPC applications and to interact with HPC infrastructure.