Development of a new fast proxy model for transport in multi-scale heterogeneous porous media based on random walk techniques

基于随机游走技术的多尺度异质多孔介质传输的新型快速代理模型的开发

• 批准号: 402433-2011
• 负责人: Leung, Juliana
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=573280
• 关键词: Development; new; fast; proxy; model

A major challenge in petroleum engineering is the assessment of heterogeneity and its impacts on reservoir performance. Since modeling of geologic formations is always carried out with insufficient data and heterogeneity tends to occur over a wide range of length scales, significant uncertainty in rock properties exists at many scales and introduces uncertainty in the ensuing recovery behavior. Fast proxy models can be used as efficient alternatives to time-consuming finite difference computations to model transport in porous media, allowing tasks associated with uncertainty assessment to be reliably accomplished. A new particle-tracking algorithm based on random walk techniques is proposed. Transport behavior is modeled numerically by launching many particles at the inlet, allowing them to hop between sites based on a pre-defined transition probability function, and tracking the time counter associated with each particle. The main novel idea proposed in this work is that transitions of concentrations, instead of individual particles, will be tracked. Results from flow simulations performed at the sub-grid domain will be used to calibrate these probability functions. Previous works focus mostly on single-phase systems and ignore effects of heterogeneity occurring at sub-grid scales. The proposed research objectives are to: (1) devise a new modeling strategy that accounts for multi-scale heterogeneities; (2) develop improved techniques for obtaining the transition probability functions that accurately represent transport physics tailored to different recovery processes. An immediate application is found in the miscible solvent injection for enhanced heavy oil recovery. The modeling technique will take into account the viscosity differences between injected and in-situ fluids. The method will be extended to immiscible flow systems by advancing saturation (instead of concentration) along streamlines, allowing a probabilistic treatment of the multi-scale heterogeneity with potential applications in modeling of geologic storage of CO2.

石油工程的一个主要挑战是评估非均质性及其对储层性能的影响。由于地质构造的建模总是在数据不足的情况下进行，并且在大范围的长度尺度上往往会出现异质性，因此在许多尺度上都存在岩石性质的显着不确定性，并给随后的恢复行为带来了不确定性。快速代理模型可以用作耗时的有限差分计算的有效替代方案，以模拟多孔介质中的传输，从而可靠地完成与不确定性评估相关的任务。 提出了一种基于随机游走技术的新粒子跟踪算法。通过在入口处发射许多粒子，允许它们根据预定义的转移概率函数在站点之间跳跃，并跟踪与每个粒子相关的时间计数器，对传输行为进行数字建模。这项工作提出的主要新颖想法是，将跟踪浓度的转变，而不是单个粒子。在子网格域执行的流动模拟的结果将用于校准这些概率函数。以前的工作主要关注单相系统，而忽略了子电网尺度上发生的异质性的影响。拟议的研究目标是：（1）设计一种新的建模策略来解释多尺度异质性； (2) 开发改进的技术来获得转移概率函数，该函数准确地表示适合不同恢复过程的输运物理。 直接应用在用于提高重油采收率的混溶溶剂注入中。建模技术将考虑注入流体和原位流体之间的粘度差异。该方法将通过沿流线推进饱和度（而不是浓度）扩展到不混溶流系统，从而允许对多尺度异质性进行概率处理，并在二氧化碳地质封存建模中具有潜在应用。