Download or read book Comparing Stress Permeability Models for Various Lithologies Through Permeability Compliance Pore Spacing and Bulk Modulus written by Mohammad Al Noaimi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We compare leading models for permeability evolution as a function of changing effective stress for various lithologies. In particular, the permeability compliance model as given in the literature is analyzed and compared to the cubic law, where changing pore aperture is cast in terms of pore spacing, bulk modulus, and changing pore pressure. Using equivalence relationships, it is shown that empirically derived values of permeability compliance for various lithologies can be used to determine the average spacing between pores used in the cubic law and related to the material strength of the rock (Bulk modulus). We derive equations for different rock types to calculate the pore network for each rock. In addition, we use values from the literature for bulk modulus for each lithology to calculate the permeability compliance and find excellent agreement with values for permeability evolution with changing stress found in the literature. The cubic law predicts permeability loss under the same conditions based on the density of pores (number and size per unit volume). If a rock has a denser pore network (small s/b) it will have more pores available to accommodate a given deformation, leading to smaller permeability loss. We find that the term (s/b*1/K) found in the cubic law is proportional to the permeability compliance, where s is the average spacing between pores, b is the average pore diameter, and K is the bulk modulus. Therefore, permeability compliance can be viewed as a description of a rock's ability to resist permeability loss due to the pore network's compression during pressure-driven deformation.
Download or read book THE ROLE OF PORE STRUCTURE IN PERMEABILITY EVOLUTION OBSERVED IN LABORATORY STUDIES OF MARCELLUS AND WOLFCAMP SHALE written by Brandon Schwartz and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We explored the role of pore geometry and stiffness on the distribution of strain around pores for Marcellus and Wolfcamp shales. Relationships exist to model permeability evolution as well as bulk stiffness evolutionhere we find a relationship relating these two variables to each other. Whereas bulk stiffness is determined by bulk mineralogy and initial pore structure, evolving bulk stiffness is determined by the evolution of the pore structure alone. Permeability evolution is also determined by the evolution of the pore structure. We cast the permeability evolution in terms of evolving material properties including the Poisson ratio, the crack density parameter, and the bulk modulusall of which can be measured via acoustic waves. The end result is a method to measure permeability evolution via acoustic waves alone.We modeled the effects of fracture spacing, aspect ratio, and pore stiffness on the permeability evolution of an ellipsoid crack under uniaxial stress and varying pore pressure. We found that rocks undergoing identical compressional strain and pore pressure can undergo significantly different magnitudes of fracture closure or dilation based on these three variables. This is especially important is gas shales, where nano-porosity is challenging to characterize and heterogeneity between basins has led to disparate permeability responses in the field and in the laboratory. We found that the aspect ratio is the most sensitive parameter influencing pore compressibility. The fracture spacing becomes important when external stress is applied, but it has no significant effect when pore pressure is varied is the absence of external stress. To capture effects of mineral distribution around pores, we simulated mismatches between a pores skeletal stiffness and the surrounding matrix and determined that for a given strain soft pores relative to the bulk material experience greater permeability evolution than pores that are stiff relative to the surrounding matrix. While soft pores experience greater closure than stiff pores for a given applied stress, they also experience a greater amount of dilation when pore pressure increases. This highlights that while some shale basins such as the Marcellus can experience large permeability drops relative to other basins given the same production conditions, pressure maintenance may be the most important tool to preserve permeability. We compare the permeability response of Marcellus shale to Wolfcamp shale under changing strain to explore differences in pore structure between them. This work highlights that while magnitude of strain for a given stress is determined predominantly through a shales mineral composition, the response of transport properties to a given strain are dependent on fracture spacing, fracture geometry, and mineral distribution around pores. We dynamically stress samples of Marcellus and Wolfcamp shales and observed levels of compaction, creep, and permeability evolution. We characterize the differences between the two shales using bulk mineralogy, SEM imaging with elemental analysis, and the cubic law for permeability evolution. We find that the Marcellus shale is comprised predominantly of clays that leads to more deformation when stressed than the Wolfcamp shale which is composed predominantly of quartz and calcite. The level of creep and compaction are directly related to the amount of clay in each shale sample. Modifications to the cubic law for fluid flow reveal that Marcellus shale has a lower fracture density than the Wolfcamp shale, that the pore geometry more closely resembles slit-like pores, and that the mineral distribution around the pore space is soft compared to the Wolfcamp shale. These differences cause the Marcellus shale to experience much greater permeability reduction under the same compressive strain than the Wolfcamp. The result of our study is a unique strain-driven model to capture permeability evolution in shale due to differences in pore structure.We show that nitrogen flooding can double matrix permeability of gas shales. In laboratory experiments, nitrogen gas increased permeability in the bedding-parallel and bedding-perpendicular directions by 206% and 234%, respectively. Experiments are performed at constant stress, pore pressure, and temperature. We build a model to show that the permeability enhancement is controlled by the sorptive strain, pore geometry, and the spacing-to-aperture ratio. This work addresses how an organic-poor shale can experience large permeability changes driven by sorption induced strains. We plot methane and helium permeability curves as a function of pore pressure to isolate the portion of permeability evolution controlled by sorption. We independently build strain curves to solve for the sorptive strain and find good agreement between these two methods. This work demonstrates that matrix permeability in gas shales can be doubled, which suggests that ultimate recovery can be improved as well.We explore relationships among bulk modulus, crack density, and permeability through repetitive loading of Marcellus shale. Cumulative cyclic stressing (22-26 MPa with confinement of 24 MPa) is applied at a frequency of 0.05 Hz over 100,000 cycles. Changes in acoustic velocities are used to follow changes in dynamic bulk modulus, Poisson ratio, and crack density and to correlate these with bedding-parallel measurements of methane permeability. The shale is represented as an orthotropic elastic medium containing a dominant, noninteracting fracture set separated by thin laminae. An effective continuum model links permeability evolution to the evolution of the bulk modulus and crack density. Bulk modulus is linearly related to crack density by a scaling parameter representing rock fabric and fracture geometry. The Poisson ratio and bulk modulus of the intact, uncracked shale are deduced from our data. We propose a method for tracking permeability evolution of finely laminated shale using acoustic waves.
Download or read book Unconventional Reservoir Geomechanics written by Mark D. Zoback and published by Cambridge University Press. This book was released on 2019-05-16 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive overview of the key geologic, geomechanical and engineering principles that govern the development of unconventional oil and gas reservoirs. Covering hydrocarbon-bearing formations, horizontal drilling, reservoir seismology and environmental impacts, this is an invaluable resource for geologists, geophysicists and reservoir engineers.
Download or read book Effects of Stress Pore Pressure and Pore Fluids on Bulk Strain Velocity and Permeability in Rocks written by Karl B. Coyner and published by . This book was released on 1984 with total page 722 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Analysis of Geopressure for Geoscientists and Engineers written by Nader C. Dutta and published by Cambridge University Press. This book was released on 2021-03-11 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geopressure, or pore pressure in subsurface rock formations impacts hydrocarbon resource estimation, drilling, and drilling safety in operations. This book provides a comprehensive overview of geopressure analysis bringing together rock physics, seismic technology, quantitative basin modeling and geomechanics. It provides a fundamental physical and geological basis for understanding geopressure by explaining the coupled mechanical and thermal processes. It also brings together state-of-the-art tools and technologies for analysis and detection of geopressure, along with the associated uncertainty. Prediction and detection of shallow geohazards and gas hydrates is also discussed and field examples are used to illustrate how models can be practically applied. With supplementary MATLAB® codes and exercises available online, this is an ideal resource for students, researchers and industry professionals in geoscience and petroleum engineering looking to understand and analyse subsurface formation pressure.
Download or read book The Rock Physics Handbook written by Gary Mavko and published by Cambridge University Press. This book was released on 2009-04-30 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: A significantly expanded new edition of this practical guide to rock physics and geophysical interpretation for reservoir geophysicists and engineers.
Download or read book The Rock Physics Handbook written by Gary Mavko and published by Cambridge University Press. This book was released on 2020-01-09 with total page 741 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brings together widely scattered theoretical and laboratory rock physics relations critical for modelling and interpretation of geophysical data.
Download or read book Physical Properties of Rocks and Minerals written by Yeram Sarkis Touloukian and published by McGraw-Hill Companies. This book was released on 1981 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Engineering Geology for Underground Rocks written by Suping Peng and published by Springer Science & Business Media. This book was released on 2007-10-14 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professionals and students in any geology-related field will find this an essential reference. It clearly and systematically explains underground engineering geology principles, methods, theories and case studies. The authors lay out engineering problems in underground rock engineering and how to study and solve them. The book specially emphasizes mechanical and hydraulic couplings in rock engineering for wellbore stability, mining near aquifers and other underground structures where inflow is a problem.
Download or read book Earthquake and Volcano Deformation written by Paul Segall and published by Princeton University Press. This book was released on 2010-01-04 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake and Volcano Deformation is the first textbook to present the mechanical models of earthquake and volcanic processes, emphasizing earth-surface deformations that can be compared with observations from Global Positioning System (GPS) receivers, Interferometric Radar (InSAR), and borehole strain- and tiltmeters. Paul Segall provides the physical and mathematical fundamentals for the models used to interpret deformation measurements near active faults and volcanic centers. Segall highlights analytical methods of continuum mechanics applied to problems of active crustal deformation. Topics include elastic dislocation theory in homogeneous and layered half-spaces, crack models of faults and planar intrusions, elastic fields due to pressurized spherical and ellipsoidal magma chambers, time-dependent deformation resulting from faulting in an elastic layer overlying a viscoelastic half-space and related earthquake cycle models, poroelastic effects due to faulting and magma chamber inflation in a fluid-saturated crust, and the effects of gravity on deformation. He also explains changes in the gravitational field due to faulting and magmatic intrusion, effects of irregular surface topography and earth curvature, and modern concepts in rate- and state-dependent fault friction. This textbook presents sample calculations and compares model predictions against field data from seismic and volcanic settings from around the world. Earthquake and Volcano Deformation requires working knowledge of stress and strain, and advanced calculus. It is appropriate for advanced undergraduates and graduate students in geophysics, geology, and engineering. Professors: A supplementary Instructor's Manual is available for this book. It is restricted to teachers using the text in courses. For information on how to obtain a copy, refer to: http://press.princeton.edu/class_use/solutions.html
Download or read book Compressibility of Sandstones written by R.W. Zimmerman and published by Elsevier. This book was released on 1990-11-19 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a comprehensive treatment of the elastic volumetric response of sandstones to variations in stress. The theory and data presented apply to the deformations that occur, for example, due to withdrawal of fluid from a reservoir, or due to the redistribution of stresses caused by the drilling of a borehole. Although the emphasis is on reservoir-type sandstones, results and methods discussed are also applicable to other porous rocks. Part One concerns the effect of stress on deformation and discusses porous rock compressibility coefficients. Elasticity theory is used to derive relationships between the porous rock compressibility coefficients, the porosity, and the mineral grain compressibility. Theoretical bounds on the compressibility coefficients are derived. The concept of effective stress coefficients is examined, as is the integrated form of the stress-strain relationships. Undrained compression and induced pore pressures are treated within the same general framework. Part One is concluded with a brief, elementary introduction to Biot's theory of poroelasticity. All the results in Part One are illustrated and verified with extensive references to published compressibility data. Part Two deals with the relationship between pore structure and compressibility, and presents methods that permit quantitative prediction of the compressibility coefficients. Two- and three-dimensional models of tubular pores, spheroidal pores, and crack-like "grain boundary" voids are analyzed. A critical review is made of various methods that have been proposed to relate the effective elastic moduli (bulk and shear) of a porous material to its pore structure. Methods for extracting pore aspect ratio distributions from stress-strain data or from acoustic measurements are presented, along with applications to actual sandstone data. Part Three is a brief summary of experimental techniques that are used to measure porous rock compressibilities in the laboratory. The information contained in this volume is of interest to petroleum engineers, specifically those involved with reservoir modeling, petroleum geologists, geotechnical engineers, hydrologists and geophysicists.
Download or read book Geologic Fracture Mechanics written by Richard A. Schultz and published by Cambridge University Press. This book was released on 2019-08-08 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to geologic fracture mechanics covering geologic structural discontinuities from theoretical and field-based perspectives.
Download or read book Physical Properties of Rocks written by Jürgen Schön and published by Elsevier. This book was released on 2011-08-02 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: A symbiosis of a brief description of physical fundamentals of the rock properties (based on typical experimental results and relevant theories and models) with a guide for practical use of different theoretical concepts.
Download or read book Volcanic Unrest written by Joachim Gottsmann and published by Springer. This book was released on 2018-12-18 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book summarizes the findings of the VUELCO project, a multi-disciplinary and cross-boundary research funded by the European Commission's 7th framework program. It comprises four broad topics: 1. The global significance of volcanic unrest 2. Geophysical and geochemical fingerprints of unrest and precursory activity 3. Magma dynamics leading to unrest phenomena 4. Bridging the gap between science and decision-making Volcanic unrest is a complex multi-hazard phenomenon. The fact that unrest may, or may not lead to an imminent eruption contributes significant uncertainty to short-term volcanic hazard and risk assessment. Although it is reasonable to assume that all eruptions are associated with precursory activity of some sort, the understanding of the causative links between subsurface processes, resulting unrest signals and imminent eruption is incomplete. When a volcano evolves from dormancy into a phase of unrest, important scientific, political and social questions need to be addressed. This book is aimed at graduate students, researchers of volcanic phenomena, professionals in volcanic hazard and risk assessment, observatory personnel, as well as emergency managers who wish to learn about the complex nature of volcanic unrest and how to utilize new findings to deal with unrest phenomena at scientific and emergency managing levels. This book is open access under a CC BY license.
Download or read book Introduction to Permanent Plug and Abandonment of Wells written by Mahmoud Khalifeh and published by Springer Nature. This book was released on 2020-01-27 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book offers a timely guide to challenges and current practices to permanently plug and abandon hydrocarbon wells. With a focus on offshore North Sea, it analyzes the process of plug and abandonment of hydrocarbon wells through the establishment of permanent well barriers. It provides the reader with extensive knowledge on the type of barriers, their functioning and verification. It then discusses plug and abandonment methodologies, analyzing different types of permanent plugging materials. Last, it describes some tests for verifying the integrity and functionality of installed permanent barriers. The book offers a comprehensive reference guide to well plugging and abandonment (P&A) and well integrity testing. The book also presents new technologies that have been proposed to be used in plugging and abandoning of wells, which might be game-changing technologies, but they are still in laboratory or testing level. Given its scope, it addresses students and researchers in both academia and industry. It also provides information for engineers who work in petroleum industry and should be familiarized with P&A of hydrocarbon wells to reduce the time of P&A by considering it during well planning and construction.
Download or read book Rock Fractures and Fluid Flow written by National Research Council and published by National Academies Press. This book was released on 1996-08-27 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding of fluid flow in rock fracturesâ€"a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storageâ€"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.
Download or read book Characterization Modeling Monitoring and Remediation of Fractured Rock written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2021-01-29 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.
