Download or read book Integrated Evaluation of Structural Uncertainty Using History Matching from Seismic Imaging Uncertainty Model written by Satomi Suzuki and published by . This book was released on 2007 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural uncertainty is the first-order uncertainty in reservoir modeling both in terms of (1) the difficulty of structural interpretation due to limited data acquisition/quality and (2) the magnitude of its impact on uncertainty in hydrocarbon in-place and fluid flow performance. Though it is a common practice to consider structural uncertainty in the evaluation of hydrocarbon in-place in the appraisal phase of field developments, structural uncertainty is rarely considered when evaluating future production performance in the production phase. The reason is mainly the difficulty in integrating dynamic data into structural uncertainty modeling. This research aims at developing a method/workflow for structural uncertainty modeling which integrates geophysical and geological data during the process of history matching. This dissertation first proposes a semiautomatic seismic interpretation method using geostatistical pattern simulation. From the resulting multiple structural interpretations, a prior stochastic structural model is built and used as a geological/geophysical constraint for the subsequent history matching. Next, a new history matching method is proposed: numerical models are inverted from dynamic fluid flow response while honoring the previous structural model. The method consists of searching for numerical models that match production history from a large set of prior structural model realizations. To make such a search effective, a parameter space defined with a "similarity distance" is introduced. The inverse solutions are found in this space using a stochastic search method. Synthetic but realistic reservoir examples are presented to demonstrate the proposed workflow/methods.
Download or read book Towards Reducing Structural Interpretation Uncertainties Using Seismic Data written by Modeste Irakarama and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subsurface structural models are routinely used for resource estimation, numerical simulations, and risk management; it is therefore important that subsurface models represent the geometry of geological objects accurately. The first step in building a subsurface model is usually to interpret structural features, such as faults and horizons, from a seismic image; the identified structural features are then used to build a subsurface model using interpolation methods. Subsurface models built this way therefore inherit interpretation uncertainties since a single seismic image often supports multiple structural interpretations. In this manuscript, I study the problem of reducing interpretation uncertainties using seismic data. In particular, I study the problem of using seismic data to determine which structural models are more likely than others in an ensemble of geologically plausible structural models. I refer to this problem as "appraising structural models using seismic data". I introduce and formalize the problem of appraising structural interpretations using seismic data. I propose to solve the problem by generating synthetic data for each structural interpretation and then to compute misfit values for each interpretation; this allows us to rank the different structural interpretations. The main challenge of appraising structural models using seismic data is to propose appropriate data misfit functions. I derive a set of conditions that have to be satisfied by the data misfit function for a successful appraisal of structural models. I argue that since it is not possible to satisfy these conditions using vertical seismic profile (VSP) data, it is not possible to appraise structural interpretations using VSP data in the most general case. The conditions imposed on the data misfit function can in principle be satisfied for surface seismic data. In practice, however, it remains a challenge to propose and compute data misfit functions that satisfy those conditions. I conclude the manuscript by highlighting practical issues of appraising structural interpretations using surface seismic data. I propose a general data misfit function that is made of two main components: (1) a residual operator that computes data residuals, and (2) a projection operator that projects the data residuals from the data-space into the image-domain. This misfit function is therefore localized in space, as it outputs data misfit values in the image-domain. However, I am still unable to propose a practical implementation of this misfit function that satisfies the conditions imposed for a successful appraisal of structural interpretations; this is a subject for further research.
Download or read book Excitation Model and Analysis Uncertainties in Seismic Assessment of Bridges written by Mohammad Reza Falamarz Sheikhabadi and published by . This book was released on 2017 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: In seismic assessments, structural engineers must visualize the structure and its environment. As a matter of fact, the visualized system is obviously not the actual one, and, hence, the numerical simulation of structural systems possess some inherent uncertainties associated with the simplification/abstraction. The uncertainty sources affecting the seismic assessment of structures are often characterized as either aleatoric or epistemic in nature. Aleatoric uncertainty refers to randomness, i.e. stems from the unpredictable nature of events, and epistemic uncertainty refers to the lack of knowledge, i.e. stems from incomplete data, ignorance, or modeling assumptions. The main objective of this dissertation is to examine the current strategy in seismic design/assessment of bridges by considering the effect of various sources of uncertainty. This research effort investigates the impact of three main sources of uncertainty in seismic assessments, i.e. excitation scenario, system modeling strategy, and analysis methodology, on the reliability of the computational prediction of the seismic behavior of bridges. Analytical considerations and numerical results of the present study highlight the difficulties with the conventional procedures proposed by codes in the seismic design/assessment of bridges, and provide practice-oriented recommendations for: (1) increasing the reliability of the numerical results, and (2) decreasing the dispersion of the structural response.
Download or read book Quantifying Uncertainty in Subsurface Systems written by Céline Scheidt and published by John Wiley & Sons. This book was released on 2018-04-27 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under the Earth’s surface is a rich array of geological resources, many with potential use to humankind. However, extracting and harnessing them comes with enormous uncertainties, high costs, and considerable risks. The valuation of subsurface resources involves assessing discordant factors to produce a decision model that is functional and sustainable. This volume provides real-world examples relating to oilfields, geothermal systems, contaminated sites, and aquifer recharge. Volume highlights include: • A multi-disciplinary treatment of uncertainty quantification • Case studies with actual data that will appeal to methodology developers • A Bayesian evidential learning framework that reduces computation and modeling time Quantifying Uncertainty in Subsurface Systems is a multidisciplinary volume that brings together five major fields: information science, decision science, geosciences, data science and computer science. It will appeal to both students and practitioners, and be a valuable resource for geoscientists, engineers and applied mathematicians. Read the Editors’ Vox: https://eos.org/editors-vox/quantifying-uncertainty-about-earths-resources
Download or read book Abstracts Volume written by and published by . This book was released on 2004 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Reliability Assessment of Structures Incorporating Modeling Uncertainty and Implications for Seismic Collapse Safety written by Beliz Ugurhan Gokkaya and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Advancements in nonlinear dynamic simulation, seismic hazard analysis, and performance-based earthquake engineering are enabling more scientific assessment of structural collapse risk and how the risk is controlled by building code design requirements. Although current collapse assessment methods carefully account for the nonlinear response of structures, most of these analyses do not explicitly capture model uncertainties associated with variability in the structural properties and response characteristics of components. Instead, modeling uncertainties are typically considered through simplified assumptions and techniques. This dissertation focuses on modeling uncertainty in seismic performance assessment and implications on seismic collapse safety of structures. A statistical framework assessing model parameter correlations from component tests is proposed for characterizing the modeling parameters that define dynamic response at a component level and the interactions of multiple uncertain components in structural systems. The framework is illustrated using a dataset that is composed of over two-hundred tests of reinforced concrete columns. Statistics of the model parameters are established including the correlation structure of the inelastic model parameters, both within a component and between different components. The analyses show that model parameters within structural components tend to be only mildly correlated, whereas there are strong correlations between like parameters of different components within a building. Uncertainty propagation methods, including Monte-Carlo simulation-based, moment-based and surrogate (response surface and neural network) methods, are assessed for probabilistic assessment of collapse risk. To reduce computational demand of collapse risk assessment, a Bayesian approach is proposed and demonstrated using a reinforced concrete archetype building. The results emphasize the sensitivity of collapse response to modeling uncertainties and the challenges of balancing of computational efficiency and robust uncertainty characterization. Impacts of modeling uncertainty are evaluated for fragility functions and mean annual exceedance rates for drift limits and collapse for thirty-three reinforced concrete archetype building configurations. Modeling uncertainty is shown to have considerable impacts on collapse risk. Inclusion of modeling uncertainty is shown to increase the mean annual frequency of collapse by about 1.7 times, as compared to analyses based on median model parameters, for a high-seismic site in California. Modeling uncertainty has a smaller effect on drift demands at levels usually considered in building codes. A novel method is introduced to relate drift demands to collapse safety through a joint distribution of deformation demand and capacity, taking into account simulated instances of collapse and no-collapse. This method enables linking seismic performance goals specified in building codes to drift limits and other acceptance criteria. The distributions of drift demand at maximum considered earthquake level and drift capacity of case study structures are compared with drift limits as specified in the proposed seismic criteria for the next edition (2016) of ASCE 7.
Download or read book Quantifying the Effects of Modeling Uncertainty on the Seismic Performance Assessment of a Non ductile Reinforced Concrete Masonry infilled Frame Structure written by Mathias Haindl and published by . This book was released on 2020 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantifying and propagating aleatory and epistemic uncertainty in nonlinear structural response simulation is key to robust performance-based seismic assessments. In this thesis, the focus is on the probabilistic seismic performance assessment of a non-ductile three-story reinforced concrete infilled frame building. The uncertainty in ground motion records and the uncertainty embedded in structural model parameters are explicitly considered. An equivalent strut model is used for the masonry infill walls, where the six constitutive parameters that define its backbone curve are treated as random variables. The variability in these parameters is characterized by developing correlated and uncorrelated distributions of the deduced-to-predicted ratios using data from 113 experimental tests. The uncertainties are propagated using Latin hypercube sampling to generate randomized structural model realizations. Multiple stripe analysis is performed with hazard-consistent ground motions. The effect of considering modeling uncertainty is investigated in terms of the distributions of maximum story drift ratios and drift based fragility functions. It is shown that the inclusion of modeling uncertainty has significant effects on the seismic performance of the case study building. The dispersion in the response and the mean annual frequency of exceeding the drift-based limit states are increased when modeling uncertainty is included. The initial stiffness of the infill walls is observed to have the most significant contribution to the performance of the building.
Download or read book SPE Formation Evaluation written by and published by . This book was released on 1996 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Identification of an Appropriate Data Assimilation Approach in Seismic History Matching and Its Effect on Prediction Uncertainty written by Nureddin R. Edris and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Joining Statistics and Geophysics for Assessment and Uncertainty Quantification of Three dimensional Seismic Earth Models written by Carène Larmat and published by . This book was released on 2017 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic inversions produce seismic models, which are 3-dimensional (3D) images of wave velocity of the entire planet retrieved by fitting seismic measurements made on records of past earthquakes or other seismic events. Computing power of the TeraFlop era, along with the dataflow from new, very dense, seismic arrays, has led to a new generation of 3D seismic Earth models with an unprecedented level of resolution. Here we compare two recent models of western United States from the Dynamic North America (DNA) seismic imaging effort. The two models only differ in the wave propagation that was used for their inversion: one is based on ray theory (RT), and the other on finite frequency (FF). We evaluate the two models using an independent numerical method and statistical tests. We show that they differ in how they produce seismic signals from a subset of earthquakes that were used in the original inversion and were recorded on the US array. This is especially true for measurements done in the Yellowstone area which has a large negative seismic anomaly. This result is of importance for seismologists who have been debating on the practical benefit of using FF in ill-posed Earth inversions. Model evaluation, such as the one reported here, represents an opportunity for collaboration between geophysical and statistical communities. More opportunities should arise with the upcoming Exascale era, which will provide enough computational power to explore together several sources of errors in models with thousands of parameters, opening the way of uncertainty quantification of seismic models.
Download or read book Fundamental Controls on Fluid Flow in Carbonates written by S.M. Agar and published by Geological Society of London. This book was released on 2015-02-02 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights key challenges for fluid-flow prediction in carbonate reservoirs, the approaches currently employed to address these challenges and developments in fundamental science and technology. The papers span methods and case studies that highlight workflows and emerging technologies in the fields of geology, geophysics, petrophysics, reservoir modelling and computer science. Topics include: detailed pore-scale studies that explore fundamental processes and applications of imaging and flow modelling at the pore scale; case studies of diagenetic processes with complementary perspectives from reactive transport modelling; novel methods for rock typing; petrophysical studies that investigate the impact of diagenesis and fault-rock properties on acoustic signatures; mechanical modelling and seismic imaging of faults in carbonate rocks; modelling geological influences on seismic anisotropy; novel approaches to geological modelling; methods to represent key geological details in reservoir simulations and advances in computer visualization, analytics and interactions for geoscience and engineering.
Download or read book Petroleum Geology of NW Europe written by B. Levell and published by Geological Society of London. This book was released on 2018-02-15 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the Geological Society on behalf of PGC Ltd. (1 hardback volume in slipcase). The 8th Conference on the Petroleum Geology of NW Europe was held in September 2015 and marked the 50th anniversary of the first commercial discovery offshore in the North Sea (West Sole, in September 1965). Its focus was ‘50 Years of Learning – a Platform for Present Value and Future Success’ and its objective was to provide an update on discoveries, developments, technologies and geological concepts from the region. The 39 extensively illustrated technical papers cover the full width of recent activity and are divided into the following sections: Plays and fairways; Play assessment; Recent successes and learnings from failures; Infrastructure-led exploration and development; Late-life fields, re-development and the ‘next life’; Onshore exploration and development. The proceedings volume follows the format of many of the previous conferences since the first in 1974. Collectively these provide a unique documentation of the discovery and development of several NW European hydrocarbon provinces. The volume will be of interest to all geoscientists involved in exploration and development in NW Europe. It provides a fascinating overview of how creativity can continue to reveal hidden resources in an area that has been called ‘mature’ for at least the last 20 of its 50-year history.
Download or read book Geostatistics Tr ia 92 written by A.O. Soares and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1097 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contributions in this book were presented at the Fourth International Geostatistics Congress held in Tróia, Portugal, in September 1992. They provide a comprehensive account of the current state of the art of geostatistics, including recent theoretical developments and new applications. In particular, readers will find descriptions and applications of the more recent methods of stochastic simulation together with data integration techniques applied to the modelling of hydrocabon reservoirs. In other fields there are stationary and non-stationary geostatistical applications to geology, climatology, pollution control, soil science, hydrology and human sciences. The papers also provide an insight into new trends in geostatistics particularly the increasing interaction with many other scientific disciplines. This book is a significant reference work for practitioners of geostatistics both in academia and industry.
Download or read book Handbook of Mathematical Geosciences written by B.S. Daya Sagar and published by Springer. This book was released on 2018-06-25 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Open Access handbook published at the IAMG's 50th anniversary, presents a compilation of invited path-breaking research contributions by award-winning geoscientists who have been instrumental in shaping the IAMG. It contains 45 chapters that are categorized broadly into five parts (i) theory, (ii) general applications, (iii) exploration and resource estimation, (iv) reviews, and (v) reminiscences covering related topics like mathematical geosciences, mathematical morphology, geostatistics, fractals and multifractals, spatial statistics, multipoint geostatistics, compositional data analysis, informatics, geocomputation, numerical methods, and chaos theory in the geosciences.
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 Leading Edge written by and published by . This book was released on 2006 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Uncertainty in the Earth Sciences written by Jef Caers and published by John Wiley & Sons. This book was released on 2011-05-25 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modeling Uncertainty in the Earth Sciences highlights the various issues, techniques and practical modeling tools available for modeling the uncertainty of complex Earth systems and the impact that it has on practical situations. The aim of the book is to provide an introductory overview which covers a broad range of tried-and-tested tools. Descriptions of concepts, philosophies, challenges, methodologies and workflows give the reader an understanding of the best way to make decisions under uncertainty for Earth Science problems. The book covers key issues such as: Spatial and time aspect; large complexity and dimensionality; computation power; costs of 'engineering' the Earth; uncertainty in the modeling and decision process. Focusing on reliable and practical methods this book provides an invaluable primer for the complex area of decision making with uncertainty in the Earth Sciences.
