Both the beauty and interest of fractures and fracture networks are easy to grasp, since they are abundant in nature. An example is the road from Digne to Nice in the south of France, with an impressive number and variety of such structures: the road for the most part, goes through narrow valleys with fast running streams penetrating the rock faces; erosion is favored by the Mediterranean climate, so that rocks are barely covered by meager vegetation. In this inhospitable and sterile landscape, the visitor can im mediately discover innumerable fractures in great masses which have been distorted by slow, yet powerful movements. This phenomenon can be seen for about 100 kilometers; all kinds of shapes and combinations are repre sented and can be observed either in the mountain itself or in the man-made cliffs and excavations, resulting from improvements made to the road. In the same region, close to the Turini Pass, a real large scale hydrody namic experiment is taking place -a source which is situated on the flank on the mountain, has been equiped with a tap; if the tap is open, water flows through the tap only, but when it is closed, then the side of the mountain releases water in a matter of seconds. Other outlets are also influenced by this tap, such as a water basin situated a few hundred meters away.

This book presents and describes an innovative method to simulate the growth of natural fractural networks in different geological environments, based on their geological history and fundamental geomechanical principles. The book develops techniques to simulate the growth and interaction of large populations of layer-bound fracture directly, based on linear elastic fracture mechanics and subcritical propagation theory. It demonstrates how to use these techniques to model the nucleation, propagation and interaction of layer-bound fractures in different orientations around large scale geological structures, based on the geological history of the structures. It also explains how to use these techniques to build more accurate discrete fracture network (DFN) models at a reasonable computational cost. These models can explain many of the properties of natural fracture networks observed in outcrops, using actual outcrop examples. Finally, the book demonstrates how it can be incorporated into flow modelling workflows using subsurface examples from the hydrocarbon and geothermal industries. Modelling the Evolution of Natural Fracture Networks will be of interest to anyone curious about understanding and predicting the evolution of complex natural fracture networks across large geological structures. It will be helpful to those modelling fluid flow through fractures, or the geomechanical impact of fracture networks, in the hydrocarbon, geothermal, CO2 sequestration, groundwater and engineering industries.

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.

Discrete Fracture Network Modeling of Hydraulic Stimulation describes the development and testing of a model that couples fluid-flow, deformation, friction weakening, and permeability evolution in large, complex two-dimensional discrete fracture networks. The model can be used to explore the behavior of hydraulic stimulation in settings where matrix permeability is low and preexisting fractures play an important role, such as Enhanced Geothermal Systems and gas shale. Used also to describe pure shear stimulation, mixed-mechanism stimulation, or pure opening-mode stimulation. A variety of novel techniques to ensure efficiency and realistic model behavior are implemented, and tested. The simulation methodology can also be used as an efficient method for directly solving quasistatic fracture contact problems. Results show how stresses induced by fracture deformation during stimulation directly impact the mechanism of propagation and the resulting fracture network.

This book provides a systematic treatment of the geometrical and transport properties of fractures, fracture networks, and fractured porous media. It is divided into two major parts. The first part deals with geometry of individual fractures and of fracture networks. The use of the dimensionless density rationalizes the results for the percolation threshold of the networks. It presents the crucial advantage of grouping the numerical data for various fracture shapes. The second part deals mainly with permeability under steady conditions of fractures, fracture networks, and fractured porous media. Again the results for various types of networks can be rationalized by means of the dimensionless density. A chapter is dedicated to two phase flow in fractured porous media.

In this standard reference of the field, theoretical and experimental approaches to flow, hydrodynamic dispersion, and miscible displacements in porous media and fractured rock are considered. Two different approaches are discussed and contrasted with each other. The first approach is based on the classical equations of flow and transport, called 'continuum models'. The second approach is based on modern methods of statistical physics of disordered media; that is, on 'discrete models', which have become increasingly popular over the past 15 years. The book is unique in its scope, since (1) there is currently no book that compares the two approaches, and covers all important aspects of porous media problems; and (2) includes discussion of fractured rocks, which so far has been treated as a separate subject. Portions of the book would be suitable for an advanced undergraduate course. The book will be ideal for graduate courses on the subject, and can be used by chemical, petroleum, civil, environmental engineers, and geologists, as well as physicists, applied physicist and allied scientists that deal with various porous media problems.

The development of naturally fractured reservoirs, especially shale gas and tight oil reservoirs, exploded in recent years due to advanced drilling and fracturing techniques. However, complex fracture geometries such as irregular fracture networks and non-planar fractures are often generated, especially in the presence of natural fractures. Accurate modelling of production from reservoirs with such geometries is challenging. Therefore, Embedded Discrete Fracture Modeling and Application in Reservoir Simulation demonstrates how production from reservoirs with complex fracture geometries can be modelled efficiently and effectively. This volume presents a conventional numerical model to handle simple and complex fractures using local grid refinement (LGR) and unstructured gridding. Moreover, it introduces an Embedded Discrete Fracture Model (EDFM) to efficiently deal with complex fractures by dividing the fractures into segments using matrix cell boundaries and creating non-neighboring connections (NNCs). A basic EDFM approach using Cartesian grids and advanced EDFM approach using Corner point and unstructured grids will be covered. Embedded Discrete Fracture Modeling and Application in Reservoir Simulation is an essential reference for anyone interested in performing reservoir simulation of conventional and unconventional fractured reservoirs. - Highlights the current state-of-the-art in reservoir simulation of unconventional reservoirs - Offers understanding of the impacts of key reservoir properties and complex fractures on well performance - Provides case studies to show how to use the EDFM method for different needs