Fracture Sustainability Test, Pre- and Post-Test Photomicrographs
The primary objective of this research is to understand how different rock types, mineral and fluid compositions, and fracture surface textures determine the longevity of fracture apertures, so that selection of reservoir rock can be economically optimized to reduce future refracturing. We are performing laboratory tests to study this in a custom apparatus at conditions relevant to EGS, with temperatures up to 250 degrees C (design maximum 300 degrees C). Our approach is to perform a number of long term (up to several months) laboratory experiments using relevant rock samples with different mineralogies to explore fracture sustainability under EGS conditions. We use an apparatus that allows direct application of a normal force on the fracture faces of a single fracture in a sample having a sheared, tensile fracture. We flow brine of a specified composition through the aperture, and simultaneously measure the fracture permeability and closure. We collect the effluent water for chemical and isotopic analysis. We are numerically modeling our tests and comparing experimental and numerical results.
This submission includes photomicrographs of pre-test (unreacted) and post-test (reacted) samples from Brady well BCH-03 at various depths, Desert Peak well DP 35-13, and samples of Stripa granite. The photomicrographs are provided using uncrossed and crossed polarized light (xpl). UN is uncrossed nicols, CN and xpl are crossed nicols (crossed polars). The magnification listed is just referring to the objective lens that was used, not the total magnification of the images. With a 5x objective, the bottom dimension of an image is 1.75 mm. With 10x the bottom dimension of an image is 0.875 mm, and with 2x the bottom dimension of an image is 4.375 mm.
Citation Formats
TY - DATA
AB - The primary objective of this research is to understand how different rock types, mineral and fluid compositions, and fracture surface textures determine the longevity of fracture apertures, so that selection of reservoir rock can be economically optimized to reduce future refracturing. We are performing laboratory tests to study this in a custom apparatus at conditions relevant to EGS, with temperatures up to 250 degrees C (design maximum 300 degrees C). Our approach is to perform a number of long term (up to several months) laboratory experiments using relevant rock samples with different mineralogies to explore fracture sustainability under EGS conditions. We use an apparatus that allows direct application of a normal force on the fracture faces of a single fracture in a sample having a sheared, tensile fracture. We flow brine of a specified composition through the aperture, and simultaneously measure the fracture permeability and closure. We collect the effluent water for chemical and isotopic analysis. We are numerically modeling our tests and comparing experimental and numerical results.
This submission includes photomicrographs of pre-test (unreacted) and post-test (reacted) samples from Brady well BCH-03 at various depths, Desert Peak well DP 35-13, and samples of Stripa granite. The photomicrographs are provided using uncrossed and crossed polarized light (xpl). UN is uncrossed nicols, CN and xpl are crossed nicols (crossed polars). The magnification listed is just referring to the objective lens that was used, not the total magnification of the images. With a 5x objective, the bottom dimension of an image is 1.75 mm. With 10x the bottom dimension of an image is 0.875 mm, and with 2x the bottom dimension of an image is 4.375 mm.
AU - Dobson, Pat
A2 - Nakagawa, Seiji
A3 - Kneafsey, Tim
DB - Geothermal Data Repository
DP - Open EI | National Renewable Energy Laboratory
DO - 10.15121/1666365
KW - geothermal
KW - energy
KW - fracture
KW - sustainability
KW - photomicrograph
KW - Brady well
KW - Desert Peak
KW - BCH-03
KW - DP 35-13
KW - xpl
KW - well data
KW - pre-test
KW - post-test
KW - shear-induced
KW - permeability
KW - EGS
KW - reservoir
KW - stripa granite
KW - aperture
KW - geology
KW - temperature
KW - brine
KW - shear
LA - English
DA - 2016/09/26
PY - 2016
PB - Lawrence Berkeley National Laboratory
T1 - Fracture Sustainability Test, Pre- and Post-Test Photomicrographs
UR - https://doi.org/10.15121/1666365
ER -
Dobson, Pat, et al. Fracture Sustainability Test, Pre- and Post-Test Photomicrographs. Lawrence Berkeley National Laboratory, 26 September, 2016, Geothermal Data Repository. https://doi.org/10.15121/1666365.
Dobson, P., Nakagawa, S., & Kneafsey, T. (2016). Fracture Sustainability Test, Pre- and Post-Test Photomicrographs. [Data set]. Geothermal Data Repository. Lawrence Berkeley National Laboratory. https://doi.org/10.15121/1666365
Dobson, Pat, Seiji Nakagawa, and Tim Kneafsey. Fracture Sustainability Test, Pre- and Post-Test Photomicrographs. Lawrence Berkeley National Laboratory, September, 26, 2016. Distributed by Geothermal Data Repository. https://doi.org/10.15121/1666365
@misc{GDR_Dataset_1234,
title = {Fracture Sustainability Test, Pre- and Post-Test Photomicrographs},
author = {Dobson, Pat and Nakagawa, Seiji and Kneafsey, Tim},
abstractNote = {The primary objective of this research is to understand how different rock types, mineral and fluid compositions, and fracture surface textures determine the longevity of fracture apertures, so that selection of reservoir rock can be economically optimized to reduce future refracturing. We are performing laboratory tests to study this in a custom apparatus at conditions relevant to EGS, with temperatures up to 250 degrees C (design maximum 300 degrees C). Our approach is to perform a number of long term (up to several months) laboratory experiments using relevant rock samples with different mineralogies to explore fracture sustainability under EGS conditions. We use an apparatus that allows direct application of a normal force on the fracture faces of a single fracture in a sample having a sheared, tensile fracture. We flow brine of a specified composition through the aperture, and simultaneously measure the fracture permeability and closure. We collect the effluent water for chemical and isotopic analysis. We are numerically modeling our tests and comparing experimental and numerical results.
This submission includes photomicrographs of pre-test (unreacted) and post-test (reacted) samples from Brady well BCH-03 at various depths, Desert Peak well DP 35-13, and samples of Stripa granite. The photomicrographs are provided using uncrossed and crossed polarized light (xpl). UN is uncrossed nicols, CN and xpl are crossed nicols (crossed polars). The magnification listed is just referring to the objective lens that was used, not the total magnification of the images. With a 5x objective, the bottom dimension of an image is 1.75 mm. With 10x the bottom dimension of an image is 0.875 mm, and with 2x the bottom dimension of an image is 4.375 mm.},
url = {https://gdr.openei.org/submissions/1234},
year = {2016},
howpublished = {Geothermal Data Repository, Lawrence Berkeley National Laboratory, https://doi.org/10.15121/1666365},
note = {Accessed: 2025-04-25},
doi = {10.15121/1666365}
}
https://dx.doi.org/10.15121/1666365
Details
Data from Sep 26, 2016
Last updated May 17, 2021
Submitted Sep 7, 2020
Organization
Lawrence Berkeley National Laboratory
Contact
Tim Kneafsey
510.486.4414
Authors
Keywords
geothermal, energy, fracture, sustainability, photomicrograph, Brady well, Desert Peak, BCH-03, DP 35-13, xpl, well data, pre-test, post-test, shear-induced, permeability, EGS, reservoir, stripa granite, aperture, geology, temperature, brine, shearDOE Project Details
Project Name Sustainability of Shear-Induced Permeability for EGS Reservoirs
Project Lead Lauren Boyd
Project Number FY13 AOP 5.1