Physically-Based Simulation of the Evolution and Flow Characteristics of Natural Fracture Networks

了解天然裂缝网络的几何结构对于准确解释过去的地质情况以及建立有意义的地震波传播和流体在裂缝地层中的流动和输送模型至关重要。此外，能够准确模拟天然裂缝系统几何形状的程度直接影响到我们处理诸如废物隔离、矿床成因、自然资源回收和含水层修复等重要问题的能力。该建议旨在通过将良好建立的物理原理纳入自然裂缝网络生成的模型，增加我们对控制天然裂缝网络几何特征的参数的理解。先前的研究表明，基于物理的裂缝网络模拟器（pbns）可以准确预测实验生成的裂缝集的演化。该建议旨在通过将模拟网络与露头上观察到的网络进行比较，确定控制天然裂缝网络生长的参数的适当值。了解这些生长参数的适当值对于准确模拟天然裂缝网络几何形状至关重要。该建议还寻求将PBNS应用于模拟网络的导电性分析，以识别控制裂缝地层中流体流动的关键几何参数。这些几何参数的识别，与适当的生长参数值相结合，将更准确地解释流体在裂缝地层中的运移。从这项工作中得出的天然裂缝网络模型将提高我们对裂缝系统如何由其他地质特征和过程产生和影响的理解。这种认识将提高我们准确模拟许多重要的地下过程的能力，因此，在地球科学的许多问题上都有应用。这些问题包括但不限于地震反演、自然资源回收、地壳结构力学等。

9316099 Pollard An understanding of the geometry of natural fracture networks is essential for accurate interpretations of the geologic past and for meaningful models of seismic wave propagation and fluid flow and transport through fractured formations. Further, the degree to which the geometry of natural fracture systems can be accurately simulated directly affects our ability to deal with such important problems as waste isolation, ore deposit genesis, natural resource recovery and aquifer remediation. This proposal seeks to increase our understanding of the parameters which control the geometric characteristics of natural fracture networks by incorporating well established physical principles into models for the generation of natural fracture networks. Previous investigations have demonstrated that physically-based fracture network simulators (PBNSs) can accurately predict the evolution of experimentally generated fracture sets. This proposal seeks to identify appropriate values for the parameters which control the growth of natural fracture networks by comparing simulated networks to those observed on outcrops. Knowledge of the appropriate values for these growth parameters is essential for accurate simulation of natural fracture network geometries. This proposal also seeks to apply the PBNS in an analyses of the conductivity of simulated networks in order to discern the critical geometric parameters controlling fluid flow within fractured formations. The identification of these geometric parameters, when combined with the appropriate growth parameter values, will result in more accurate interpretation of, and for, fluid migration through fractured formations. Models for natural fracture networks which result from this work will improve our understanding of how fracture systems are created by, and influence other, geologic features and processes. This understanding will enhance our ability to accurately model many important sub-sur face processes and, as such, has application to many problems in earth science. Such problems include, but are not limited to, seismic inversion, natural resource recovery and structural mechanics of the earth's crust.