An Enriched Approach for Modeling Multiscale Discrete-Fracture/Matrix Interaction for Unconventional-Reservoir Simulations

SPE Journal ◽  
2018 ◽  
Vol 24 (01) ◽  
pp. 349-374 ◽  
Author(s):  
Yang Xia ◽  
Yan Jin ◽  
Mian Chen ◽  
Kang Ping Chen
Keyword(s):  
Case Studies ◽  
Computational Efficiency ◽  
Real Field ◽  
Fracture Networks ◽  
Unconventional Reservoir ◽  
Approximation Space ◽  
Reservoir Simulations ◽  
Matrix Interaction ◽  
Wide Range ◽  
Discrete Fracture

Summary Unconventional reservoirs after formation-stimulation treatments are always characterized by complex fracture networks with a wide range of length scales and topologies. Accurate simulation on multiscale discrete-fracture/matrix interaction during transient productive flows for such reservoirs is challenging but important for reservoir evaluation, optimization, and management. In this paper, we present a new enriched and explicit method for simulation on multiscale discrete-fracture/matrix modeling (EE-DFM) on structured grids to decouple the mesh conformity between the porous media and the fractures. A hybrid structured EE-DFM is first introduced, and enrichments for different scales of fracture segments are proposed to locally enrich the conventional approximation space for representing the pressure solution surrounding multiscale fracture networks. By appropriately selecting an asymptotic function to locally enrich the conventional approximation space, typical behavior of fluid flux around features in fractured media, such as discontinuities and singularities, can be directly captured. Simulation on complex multiscale fracture networks is achieved by using the superposition principle of the enrichments without introducing additional degrees of freedom and while maintaining computational efficiency. We demonstrate the accuracy and flexibility of the method by performing a series of case studies and comparing the results with simple analytical solutions as well as with conventional numerical solutions. The results of long-term well-performance case studies are used to show the good computational efficiency of the proposed method when the complexity of fracture networks is increased. The potential of the proposed method to be incorporated into the multicontinuum concept for solving nonlinear gas transport in a shale reservoir is presented. The present study provides a promising framework for real-field multiscale discrete-fracture models for unconventional-reservoir simulations.

Numerically Simulated Groundwater Age Distributions within Complex Flow Systems and Discrete Fracture Networks

2020 ◽  
Author(s):  
John Molson ◽  
Emil Frind
Keyword(s):  
Groundwater Age ◽  
Fractured Rock ◽  
Vertical Plane ◽  
Geochemical Evolution ◽  
Real Field ◽  
Fracture Networks ◽  
Complex Flow ◽  
Discrete Fracture Networks ◽  
Discrete Fracture ◽  
Flow Systems

<p>Numerical simulations of mean groundwater age are presented for a variety of complex flow systems including heterogeneous aquifers and discretely-fractured porous rock. We apply the finite element models FLONET/TR2 (in the 2D vertical plane) and SALTFLOW (in 3D systems), using the standard advection-dispersion equation with an age source term. The age simulations are applied in a variety of contexts including defining capture zones for pumping wells, characterizing fractured rock aquifers, and for improved understanding of flow systems and geochemical evolution. Applications include real field sites and hypothetical conceptual models. Comparisons are also made with advective particle-tracking derived ages which are much faster to compute but do not include dispersive age mixing. Control of numerical (age) dispersion is critical, especially within discrete fracture networks where high age gradients can develop between the fractures and matrix. The presentation will highlight the broad applications of mean groundwater age simulations and will show how they can be useful for providing insight into hydrogeological systems.</p>

Myths of the Underworld in Contemporary Culture

2019 ◽  
Author(s):  
Judith Fletcher
Keyword(s):  
Short Stories ◽  
Case Studies ◽  
Joseph Conrad ◽  
Ezra Pound ◽  
Border Crossing ◽  
First Century ◽  
Contemporary Culture ◽  
Cinematic Adaptation ◽  
Narrative Tradition ◽  
Wide Range

Stories of a visit to the realm of the dead and a return to the upper world are among the oldest narratives in European literature, beginning with Homer’s Odyssey and extending to contemporary culture. This volume examines a series of fictional works by twentieth- and twenty-first century authors, such Toni Morrison and Elena Ferrante, which deal in various ways with the descent to Hades. Myths of the Underworld in Contemporary Culture surveys a wide range of genres, including novels, short stories, comics, a cinematic adaptation, poetry, and juvenile fiction. It examines not only those texts that feature a literal catabasis, such as Neil Gaiman’s Sandman series, but also those where the descent to the underworld is evoked in more metaphorical ways as a kind of border crossing, for instance Salman Rushdie’s use of the Orpheus myth to signify the trauma of migration. The analyses examine how these retellings relate to earlier versions of the mythical theme, including their ancient precedents by Homer and Vergil, but also to post-classical receptions of underworld narratives by authors such as Dante, Ezra Pound, and Joseph Conrad. Arguing that the underworld has come to connote a cultural archive of narrative tradition, the book offers a series of case studies that examine the adaptation of underworld myths in contemporary culture in relation to the discourses of postmodernism, feminism, and postcolonialism.

Explanation Beyond Causation

2018 ◽  
Keyword(s):  
Philosophy Of Science ◽  
Case Studies ◽  
Philosophical Study ◽  
Accurate Information ◽  
Contemporary Philosophy ◽  
Causal Information ◽  
Causal Explanations ◽  
Turn On ◽  
Detailed Case ◽  
Wide Range

Explanations are very important to us in many contexts: in science, mathematics, philosophy, and also in everyday and juridical contexts. But what is an explanation? In the philosophical study of explanation, there is long-standing, influential tradition that links explanation intimately to causation: we often explain by providing accurate information about the causes of the phenomenon to be explained. Such causal accounts have been the received view of the nature of explanation, particularly in philosophy of science, since the 1980s. However, philosophers have recently begun to break with this causal tradition by shifting their focus to kinds of explanation that do not turn on causal information. The increasing recognition of the importance of such non-causal explanations in the sciences and elsewhere raises pressing questions for philosophers of explanation. What is the nature of non-causal explanations—and which theory best captures it? How do non-causal explanations relate to causal ones? How are non-causal explanations in the sciences related to those in mathematics and metaphysics? This volume of new essays explores answers to these and other questions at the heart of contemporary philosophy of explanation. The essays address these questions from a variety of perspectives, including general accounts of non-causal and causal explanations, as well as a wide range of detailed case studies of non-causal explanations from the sciences, mathematics and metaphysics.

scholarly journals Ocean Emission Effects on Aerosol-Cloud Interactions: Insights from Two Case Studies

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Armin Sorooshian ◽  
Hanh T. Duong
Keyword(s):  
Case Studies ◽  
Field Experiments ◽  
Remote Sensing Data ◽  
Anthropogenic Pollution ◽  
Cloud Microphysics ◽  
Marine Aerosols ◽  
Aerosol Cloud ◽  
First Case ◽  
Wide Range ◽  
Aerosol Cloud Interactions

Two case studies are discussed that evaluate the effect of ocean emissions on aerosol-cloud interactions. A review of the first case study from the eastern Pacific Ocean shows that simultaneous aircraft and space-borne observations are valuable in detecting links between ocean biota emissions and marine aerosols, but that the effect of the former on cloud microphysics is less clear owing to interference from background anthropogenic pollution and the difficulty with field experiments in obtaining a wide range of aerosol conditions to robustly quantify ocean effects on aerosol-cloud interactions. To address these limitations, a second case was investigated using remote sensing data over the less polluted Southern Ocean region. The results indicate that cloud drop size is reduced more for a fixed increase in aerosol particles during periods of higher ocean chlorophyll A. Potential biases in the results owing to statistical issues in the data analysis are discussed.

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