Analysis Of The Deformation Of Saturated Porous Rocks In Compression

An investigation of the mechanical influence of interstitial fluids on the deformation process of saturated rocks has been conducted to determine the domain of validity of previously published theories. Equilibrium equations for fluid saturated materials in which the fluid is at rest or flows according to DARCY's law were derived. For this purpose, a new characterization of porosity has been proposed for analyzing porosity variation within a rock mass. This derivation indicates that the bulk material (solid plus fluid) can be represented by an equivalent homogeneous continuum for which the mass density and the stress tensor at any point depend upon average stresses and average densities of both the solid matrix and the saturating fluid as well as upon the surface and the volume porosity.

Mechanics of Fluid Saturated Rocks presents a current and comprehensive report on this emerging field that bridges the areas of geology and mechanics. It is of direct interest to a wide spectrum of earth scientists and engineers who are concerned with upper-crust mechanics and fluid movements, the most important fluids being oil and water. This authoritative book is the result of a collaborative effort between scientists in academic institutions and industry. It examines important issues such as subsidence, geological fault formation, earthquake faulting, hydraulic fracturing, transport of fluids, and natural and direct applications. Mechanics of Fluid Saturated Rocks provides a unique interdisciplinary viewpoint, as well as case studies, conclusions, and recommendations for further research. Covers the physical, chemical, and mechanical analysis of porous saturated rock deformation on both large and small scales Discusses the latest developments of importance to engineers and geologists Examines natural and direct applications Includes extensive bibliographies for each chapter

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.

Porous Rock Failure Mechanics: Hydraulic Fracturing, Drilling and Structural Engineering focuses on the fracture mechanics of porous rocks and modern simulation techniques for progressive quasi-static and dynamic fractures. The topics covered in this volume include a wide range of academic and industrial applications, including petroleum, mining, and civil engineering. Chapters focus on advanced topics in the field of rock’s fracture mechanics and address theoretical concepts, experimental characterization, numerical simulation techniques, and their applications as appropriate. Each chapter reflects the current state-of-the-art in terms of the modern use of fracture simulation in industrial and academic sectors. Some of the major contributions in this volume include, but are not limited to: anisotropic elasto-plastic deformation mechanisms in fluid saturated porous rocks, dynamics of fluids transport in fractured rocks and simulation techniques, fracture mechanics and simulation techniques in porous rocks, fluid-structure interaction in hydraulic driven fractures, advanced numerical techniques for simulation of progressive fracture, including multiscale modeling, and micromechanical approaches for porous rocks, and quasi-static versus dynamic fractures in porous rocks. This book will serve as an important resource for petroleum, geomechanics, drilling and structural engineers, R&D managers in industry and academia. Includes a strong editorial team and quality experts as chapter authors Presents topics identified for individual chapters are current, relevant, and interesting Focuses on advanced topics, such as fluid coupled fractures, rock’s continuum damage mechanics, and multiscale modeling Provides a ‘one-stop’ advanced-level reference for a graduate course focusing on rock’s mechanics

Analysis and Design Methods

This monograph deals with the part of the field of ex-' perimental rock deformation that is dominated by the phenomena of brittle fracture on one scale or another. Thus a distinction has been drawn between the fields of brittle und ductile behaviour in rock, corresponding more or less to a distinction between the phenomena of fracture and flow. It is hoped eventually to present a survey of the ductile field in a separate volume. The last chapter of this volume deals with the transition between the two fields. The scope of this survey has been limited to the mec.hanical properties of rock viewed as a material on the laboratory scale. Thus, the topic and approach is of a "materials science" kind rather than of a "structures" kind. We are dealing with only one part of the wider field of rock mechanics, which also includes structural or boundary value problems, for example, those of the stability of slopes, the collapse of mine openings, earth quakes, the folding of stratified rock, and the convec tive motion of the earth's mantle. One topic thus ex cluded is the role of jointing, which it is commonly necessary to take into account in applications in engi neering and mining, and probably often in geology too.