Deep neural network surrogates for inverse problems

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Abstract/Contents

Abstract
Inverse problems in subsurface flow are generally challenging due to the need for a large number of expensive numerical solutions to partial differential equations (PDEs). Inverse modeling typically consists of generating realizations of the unknown model parameters and matching the corresponding model's prediction to the measurements. Model errors, measurement errors, and data scarcity require one to quantify predictive uncertainty in model predictions, which further exacerbates the computational cost of inverse modeling. The latter can be ameliorated either by devising inversion frameworks that require fewer forward model runs to converge, or by constructing a much more efficient forward surrogate model that replaces the PDE solver. In this dissertation, we pursue these two strategies and apply them to three inverse problems of practical importance in subsurface applications. The common thread in this investigation is the use of deep neural network (DNN) surrogates that accelerate forward modeling by several orders of magnitude. In the three applications, we first present a study on identification of the statistical parameters of a discrete fracture network (DFN); we further focus on a higher-dimensional inverse problem on contaminant source identification; finally, we expand the unknown parameter dimension and tackle a realistic three-dimensional inverse problem, in which both a heterogeneous conductivity field and the contaminant release history are identified from sparse observations.

Description

Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2021; ©2021
Publication date 2021; 2021
Issuance monographic
Language English

Creators/Contributors

Author Zhou, Zitong
Degree supervisor Tartakovsky, Daniel
Thesis advisor Tartakovsky, Daniel
Thesis advisor Horne, Roland N
Thesis advisor Kitanidis, P. K. (Peter K.)
Degree committee member Horne, Roland N
Degree committee member Kitanidis, P. K. (Peter K.)
Associated with Stanford University, Department of Energy Resources Engineering

Subjects

Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Zitong Zhou.
Note Submitted to the Department of Energy Resources Engineering.
Thesis Thesis Ph.D. Stanford University 2021.
Location https://purl.stanford.edu/bb876gs9072

Access conditions

Copyright
© 2021 by Zitong Zhou
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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