Numerical Simulation of Pore-scale Heterogeneity and Its Effects on Elastic, Electrical and Transport Properties

Numerical Simulation of Pore-scale Heterogeneity and Its Effects on Elastic, Electrical and Transport Properties
Author: Ratnanabha Sain
Publisher: Stanford University
Total Pages: 224
Release: 2010
Genre:
ISBN:

This dissertation describes numerical experiments quantifying the influence of pore-scale heterogeneities and their evolution on macroscopic elastic, electrical and transport properties of porous media. We design, implement and test a computational recipe to construct granular packs and consolidated microstructures replicating geological processes and to estimate the link between process-to-property trends. This computational recipe includes five constructors: a Granular Dynamics (GD) simulation, an Event Driven Molecular Dynamics (EDMD) simulation and three computational diagenetic schemes; and four property estimators based on GD for elastic, finite-elements (FE) for elastic and electrical conductivity, and Lattice-Boltzmann method (LBM) for flow property simulations. Our implementation of GD simulation is capable of constructing realistic, frictional, jammed sphere packs under isotropic and uniaxial stress states. The link between microstructural properties in these packs, like porosity and coordination number (average number of contacts per grain), and stress states (due to compaction) is non-unique and depends on assemblage process and inter-granular friction. Stable jammed packs having similar internal stress and coordination number (CN) can exist at a range of porosities (38-42%) based on how fast they are assembled or compressed. Similarly, lower inter-grain friction during assemblage creates packs with higher coordination number and lower porosity at the same stress. Further, the heterogeneities in coordination number, spatial arrangement of contacts, the contact forces and internal stresses evolve with compaction non-linearly. These pore-scale heterogeneities impact effective elastic moduli, calculated by using infinitesimal perturbation method. Simulated stress-strain relationships and pressure-dependent elastic moduli for random granular packs show excellent match with laboratory experiments, unlike theoretical models based on Effective Medium Theory (EMT). We elaborately discuss the reasons why Effective Medium Theory (EMT) fails to correctly predict pressure-dependent elastic moduli, stress-strain relationships and stress-ratios (in uniaxial compaction) of granular packs or unconsolidated sediments. We specifically show that the unrealistic assumption of homogeneity in disordered packs and subsequent use of continuum elasticity-based homogeneous strain theory creates non-physical packs, which is why EMT fails. In the absence of a rigorous theory which can quantitatively account for heterogeneity in random granular packs, we propose relaxation corrections to amend EMT elastic moduli predictions. These pressure-dependent and compaction-dependent (isotropic or uniaxial) correction factors are rigorously estimated using GD simulation without non-physical approximations. Further, these correction factors heuristically represent the pressure-dependent heterogeneity and are also applicable for amending predictions of theoretical cementation models, which are conventionally used for granular packs. For predicting stress-ratios in uniaxial compaction scenario, we show the inappropriateness of linear elasticity-based equations, which use elastic constants only and do not account for dissipative losses like grain sliding. We further implement and test a computational recipe to construct consolidated microstructures based on different geological scenarios, like sorting, compaction, cementation types and cement materials. Our diagenetic trends of elastic, electrical and transport properties show excellent match with laboratory experiments on core plugs. This shows the feasibility of implementing a full-scale computational-rock-physics-based laboratory to construct and estimate properties based on geological processes. However, the elastic property estimator (FE simulation) shows limitations of finite resolution while computing elastic properties of unconsolidated sediments and fluid-saturated microstructures.

The Rock Physics Handbook

The Rock Physics Handbook
Author: Gary Mavko
Publisher: Cambridge University Press
Total Pages: 741
Release: 2020-01-09
Genre: Business & Economics
ISBN: 1108420265

Brings together widely scattered theoretical and laboratory rock physics relations critical for modelling and interpretation of geophysical data.

Geological Carbon Storage

Geological Carbon Storage
Author: Stéphanie Vialle
Publisher: John Wiley & Sons
Total Pages: 372
Release: 2018-11-15
Genre: Science
ISBN: 1119118670

Geological Carbon Storage Subsurface Seals and Caprock Integrity Seals and caprocks are an essential component of subsurface hydrogeological systems, guiding the movement and entrapment of hydrocarbon and other fluids. Geological Carbon Storage: Subsurface Seals and Caprock Integrity offers a survey of the wealth of recent scientific work on caprock integrity with a focus on the geological controls of permanent and safe carbon dioxide storage, and the commercial deployment of geological carbon storage. Volume highlights include: Low-permeability rock characterization from the pore scale to the core scale Flow and transport properties of low-permeability rocks Fundamentals of fracture generation, self-healing, and permeability Coupled geochemical, transport and geomechanical processes in caprock Analysis of caprock behavior from natural analogues Geochemical and geophysical monitoring techniques of caprock failure and integrity Potential environmental impacts of carbon dioxide migration on groundwater resources Carbon dioxide leakage mitigation and remediation techniques Geological Carbon Storage: Subsurface Seals and Caprock Integrity is an invaluable resource for geoscientists from academic and research institutions with interests in energy and environment-related problems, as well as professionals in the field.

Current Trends and Future Developments on (Bio-) Membranes

Current Trends and Future Developments on (Bio-) Membranes
Author: Angelo Basile
Publisher: Elsevier
Total Pages: 376
Release: 2023-09-14
Genre: Technology & Engineering
ISBN: 0323906737

Current Trends and Future Developments on (Bio-) Membranes: Recent Achievements for Ion-Exchange Membranes focuses on introducing and analyzing ion-exchange membranes performance and overviewing recent achievements in the structural development of ion-exchange membranes in various applications. Hence, this book is a key reference text for R&D managers in who are interested in the development of ion-exchange membrane technologies as well as academic researchers and postgraduate students working in the wider area of strategic treatments, separation and purification processes. - Reviews the ion exchange membranes, including fundamentals and processes - Provides thorough coverage of transport aspects and fundamentals of various ion-exchange membranes systems, such as fuel cells, electrodialysis, and more - Describes the two main categories of ion exchange membranes, inorganic and organic - Covers numerous new applications of ion exchange membranes

Quantitative Seismic Interpretation

Quantitative Seismic Interpretation
Author: Per Avseth
Publisher: Cambridge University Press
Total Pages: 524
Release: 2010-06-10
Genre: Science
ISBN: 1107320275

Quantitative Seismic Interpretation demonstrates how rock physics can be applied to predict reservoir parameters, such as lithologies and pore fluids, from seismically derived attributes. The authors provide an integrated methodology and practical tools for quantitative interpretation, uncertainty assessment, and characterization of subsurface reservoirs using well-log and seismic data. They illustrate the advantages of these new methodologies, while providing advice about limitations of the methods and traditional pitfalls. This book is aimed at graduate students, academics and industry professionals working in the areas of petroleum geoscience and exploration seismology. It will also interest environmental geophysicists seeking a quantitative subsurface characterization from shallow seismic data. The book includes problem sets and a case-study, for which seismic and well-log data, and MATLAB® codes are provided on a website (http://www.cambridge.org/9780521151351). These resources will allow readers to gain a hands-on understanding of the methodologies.

An Introduction to Reservoir Simulation Using MATLAB/GNU Octave

An Introduction to Reservoir Simulation Using MATLAB/GNU Octave
Author: Knut-Andreas Lie
Publisher: Cambridge University Press
Total Pages: 677
Release: 2019-08-08
Genre: Business & Economics
ISBN: 1108492436

Presents numerical methods for reservoir simulation, with efficient implementation and examples using widely-used online open-source code, for researchers, professionals and advanced students. This title is also available as Open Access on Cambridge Core.

Rock Fractures and Fluid Flow

Rock Fractures and Fluid Flow
Author: Committee on Fracture Characterization and Fluid Flow
Publisher: National Academies Press
Total Pages: 568
Release: 1996-09-10
Genre: Science
ISBN: 0309563488

Scientific understanding of fluid flow in rock fractures--a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storage--has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.