Discrete Fracture Network (DFN) Analysis to Quantify the Reliability of Borehole-Derived Volumetric Fracture Intensity
department or school: Applied Science, Faculty of
department or school: Non UBC
department or school: Mining Engineering, Keevil Institute of
data provider: DSpace
identifier citation: Ojeda, P.; Elmo, D.; Rogers, S.; Brzovic, A. Discrete Fracture Network (DFN) Analysis to Quantify the Reliability of Borehole-Derived Volumetric Fracture Intensity. Geosciences 2023, 13, 187.
creator: Ojeda, Pedro
creator: Elmo, Davide
creator: Rogers, Steve
creator: Brzovic, Andres
issued: 2023-08-30T19:48:58Z
issued: 2023-06-18
description: Volumetric fracture intensity (P32) is a parameter that plays a major role in the mechanical and hydraulic behaviour of rock masses. While methods such as Ground Penetrating Radar (GPR) are available to map the 3D geometrical characteristics of the fractures, the direct measurement of P32 at a resolution compatible with geotechnical applications is not yet possible. As a result, P32 can be estimated from the borehole and surface data using either simulation or analytical solutions. In this paper, we use Discrete Fracture Network (DFN) models to address the problem of estimating P32 using information from boreholes (1D data). When calculating P32 based on Terzaghi Weighting, it is common practice to use drill run lengths and limit the minimum angle between the borehole and the intersected fractures. The analysis presented in this paper indicated that limiting the minimum angle of intersection would result in an underestimation of the calculated P32. Additionally, the size of the interval has a significant impact on the variability of the calculated P32. We propose a methodology to calculate P32 using variable lengths, depending on the angle between the fractures and the borehole. This methodology allows the capture of the spatial variation in intensity and simultaneously avoids artificially increasing or decreasing the intensity sampled along borehole intervals. Additionally, this work has addressed the impact of boundary effects in DFN models and proposes a methodology to mitigate them.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/85698
note: Citation: Ojeda, P.; Elmo, D.; Rogers,S.; Brzovic, A. Discrete FractureNetwork (DFN) Analysis to Quantifythe Reliability of Borehole-DerivedVolumetric Fracture Intensity.Geosciences 2023, 13, 187. https://doi.org/10.3390/geosciences13060187Academic Editors: Jesús Martínez-Frías and Hongyuan LiuReceived: 26 April 2023Revised: 13 June 2023Accepted: 15 June 2023Published: 18 June 2023Copyright: © 2023 by the authors.Licensee MDPI, Basel, Switzerland.This article is an open access articledistributed under the terms andconditions of the Creative CommonsAttribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).geosciencesArticleDiscrete Fracture Network (DFN) Analysis to Quantify theReliability of Borehole-Derived Volumetric Fracture IntensityPedro Ojeda 1, Davide Elmo 2,*, Steve Rogers 1 and Andres Brzovic 11 WSP, Vancouver, BC V6Z 2M1, Canada; pedro.ojeda@wsp.com (P.O.); steve.rogers2@wsp.com (S.R.);andres.brzovic@wsp.com (A.B.)2 NBK Institute of Mining Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada* Correspondence: davide.elmo@ubc.caAbstract: Volumetric fracture intensity (P32) is a parameter that plays a major role in the mechanicaland hydraulic behaviour of rock masses. While methods such as Ground Penetrating Radar (GPR)are available to map the 3D geometrical characteristics of the fractures, the direct measurement of P32at a resolution compatible with geotechnical applications is not yet possible. As a result, P32 can beestimated from the borehole and surface data using either simulation or analytical solutions. In thispaper, we use Discrete Fracture Network (DFN) models to address the problem of estimating P32using information from boreholes (1D data). When calculating P32 based on Terzaghi Weighting, it iscommon practice to use drill run lengths and limit the minimum angle between the borehole and theintersected fractures. The analysis presented in this paper indicated that limiting the minimum angleof intersection wou…
has type: Article
is shown at: 10.14288/1.0435648
language: eng
peer review status: Reviewed
provider: Vancouver : University of British Columbia Library
publisher: Multidisciplinary Digital Publishing Institute
publisher DOI: 10.3390/geosciences13060187
rights: CC BY 4.0
rights URI: https://creativecommons.org/licenses/by/4.0/
scholar level: Faculty
scholar level: Researcher
scholar level: Other
subject: volumetric fracture intensity
subject: discrete fracture network
subject: borehole data
subject: boundary effects
type: Text
identifier URI: http://hdl.handle.net/2429/85698