Characterization of Porous and Fractured Media

Renard, Philippe; Gómez‐Hernández, J. Jaime; Ezzedine, S. M.

doi:10.1002/0470848944.hsa154

Cited by 7 publications

(6 citation statements)

References 41 publications

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“…An alternative was suggested by Guardiano and Srivastava [1993], with the multiple-point geostatistics (MPS) approach based on the assessment of the conditional probability distribution for a simulated value based on a training image (TI). MPS allows the production of images similar to those found with objectbased models, with the benefit of ease in conditioning to field data, therefore overcoming some of the major difficulties of object-based models [Renard et al, 2006]. The TI provides a conceptual but explicit representation from which high-order statistics [Mustapha and Dimitrakopoulos, 2010] can be extracted.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Earth textures by conditional image quilting

Mahmud

Mariethoz

Caers

et al. 2014

Water Resources Research

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Training image-based approaches for stochastic simulations have recently gained attention in surface and subsurface hydrology. This family of methods allows the creation of multiple realizations of a study domain, with a spatial continuity based on a training image (TI) that contains the variability, connectivity, and structural properties deemed realistic. A major drawback of these methods is their computational and/or memory cost, making certain applications challenging. It was found that similar methods, also based on training images or exemplars, have been proposed in computer graphics. One such method, image quilting (IQ), is introduced in this paper and adapted for hydrogeological applications. The main difficulty is that Image Quilting was originally not designed to produce conditional simulations and was restricted to 2-D images. In this paper, the original method developed in computer graphics has been modified to accommodate conditioning data and 3-D problems. This new conditional image quilting method (CIQ) is patch based, does not require constructing a pattern databases, and can be used with both categorical and continuous training images. The main concept is to optimally cut the patches such that they overlap with minimum discontinuity. The optimal cut is determined using a dynamic programming algorithm. Conditioning is accomplished by prior selection of patches that are compatible with the conditioning data. The performance of CIQ is tested for a variety of hydrogeological test cases. The results, when compared with previous multiplepoint statistics (MPS) methods, indicate an improvement in CPU time by a factor of at least 50.

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Section: Introductionmentioning

confidence: 99%

Simulation of Earth textures by conditional image quilting

Mahmud

Mariethoz

Caers

et al. 2014

Water Resources Research

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“…The objectives of the present investigation were to provide field-scale values of the hydraulic permeability and information about the aquifer configuration and impermeable flow boundaries. We have determined pumping test-derived values and have compared them to core permeabilities, both of which may differ significantly (Hart et al 2006, Urban and Gburek 1988, Worthington 1977, Renard et al 2006). …”

Section: Introductionmentioning

confidence: 99%

Hydraulic characterisation of the Stuttgart formation at the pilot test site for CO2 storage, Ketzin, Germany

Wiese¹,

Böhner²,

Enachescu³

et al. 2010

International Journal of Greenhouse Gas Control

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The paper presents an approach for the interpretation of hydraulic tests of a CO 2 storage reservoir. The sandstone reservoir is characterised by a fluviatile channel structure embedded in a low-permeability matrix. Pumping tests were carried out in three wells, with simultaneous pressure monitoring in each well. The hydraulic parameters (permeability and storativity) and the boundary configurations were calibrated using three different approaches: (i) parameter calibration and type curve interpretation for single-hole tests, (ii) calibration of the entire build-up phase for cross-hole tests, and (iii) calibration of the initial pressure response for cross-hole pumping tests. In addition, the arrival time of the pressure response was determined and provides additional information about the pathways of hydraulic connection. The measured pumping test permeabilities of the formation were much lower than those measured on the cores, which is very unusual. The pumping test permeabilities are mainly between 50 and 100 millidarcy (mD), while core samples show a mean aquifer permeability of 500 to 1,100 mD. Based on this it was concluded that some kind of continuous low permeability structure exists, which was supported by core material. Three possible aquifer configurations were considered. The first and second were derived from traditional pumping test analysis and were conceptualised using flow boundaries. Each of the analyses provides a different result. A method was developed in which these differences were resolved by interpreting the pressure response with respect to its spatial and temporal sensitivity. This solution lead to a third configuration which was mainly based on spatially-variable permeabilities. Taking into account the pumping test results, the geological background and the behaviour of injected CO 2 , we consider only the third configuration to be realistic. The results are in good agreement with modelled CO 2 arrival times and pressure history.

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“…protection zone design, contaminant migration prediction, aquifer remediation, seawater intrusion), has to be inferred on the basis of sparse measurements. In the past decades, a large number of techniques has been developed with the aim of characterizing the spatial variability of aquifer parameters and their uncertainty [11,26,31]. Generally speaking, the characterization of the heterogeneity can be addressed based on direct observations of the physical parameters (direct methods) or on observations of the state variables of the system (inverse methods).…”

Section: Introductionmentioning

confidence: 99%

Issues in characterizing heterogeneity and connectivity in non-multiGaussian media

Kerrou

Renard

Franssen

et al. 2008

Advances in Water Resources

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The performances of kriging, stochastic simulations and sequential self-calibration inversion are assessed when characterizing a nonmultiGaussian synthetic 2D braided channel aquifer. The comparison is based on a series of criteria such as the reproduction of the original reference transmissivity or head fields, but also in terms of accuracy of flow and transport (capture zone) forecasts when the flow conditions are modified. We observe that the errors remain large even for a dense data network. In addition some unexpected behaviours are observed when large transmissivity datasets are used. In particular, we observe an increase of the bias with the number of transmissivity data and an increasing uncertainty with the number of head data. This is interpreted as a consequence of the use of an inadequate multiGaussian stochastic model that is not able to reproduce the connectivity of the original field.

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Characterization of Porous and Fractured Media

Cited by 7 publications

References 41 publications

Simulation of Earth textures by conditional image quilting

Simulation of Earth textures by conditional image quilting

Hydraulic characterisation of the Stuttgart formation at the pilot test site for CO2 storage, Ketzin, Germany

Issues in characterizing heterogeneity and connectivity in non-multiGaussian media

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