Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS
The evolution of flow pattern along a single fracture and its effects on heat production is a fundamental problem in the assessments of engineered geothermal systems (EGS). The channelized flow pattern associated with ubiquitous heterogeneity in fracture aperture distribution causes non-uniform temperature decrease in the rock body, which makes the flow increasingly concentrated into some preferential paths through the action of thermal stress. This mechanism may cause rapid heat production deterioration of EGS reservoirs.
In this study, we investigated the effects of aperture heterogeneity on flow pattern evolution in a single fracture in a low-permeability crystalline formation. We developed a numerical model on the platform of GEOS to simulate the coupled thermo-hydro-mechanical processes in a penny-shaped fracture accessed via an injection well and a production well. We find that aperture heterogeneity generally exacerbates flow channeling and reservoir performance generally decreases with longer correlation length of aperture field. The expected production life is highly variable (5 years to beyond 30 years) when the aperture correlation length is longer than 1/5 of the well distance, whereas a heterogeneous fracture behaves similar to a homogeneous one when the correlation length is much shorter than the well distance. Besides, the mean production life decreases with greater aperture standard deviation only when the correlation length is relatively long. Although flow channeling is inevitable, initial aperture fields and well locations that enable tortuous preferential paths tend to prolong heat production lives.
Citation Formats
TY - DATA
AB - The evolution of flow pattern along a single fracture and its effects on heat production is a fundamental problem in the assessments of engineered geothermal systems (EGS). The channelized flow pattern associated with ubiquitous heterogeneity in fracture aperture distribution causes non-uniform temperature decrease in the rock body, which makes the flow increasingly concentrated into some preferential paths through the action of thermal stress. This mechanism may cause rapid heat production deterioration of EGS reservoirs.
In this study, we investigated the effects of aperture heterogeneity on flow pattern evolution in a single fracture in a low-permeability crystalline formation. We developed a numerical model on the platform of GEOS to simulate the coupled thermo-hydro-mechanical processes in a penny-shaped fracture accessed via an injection well and a production well. We find that aperture heterogeneity generally exacerbates flow channeling and reservoir performance generally decreases with longer correlation length of aperture field. The expected production life is highly variable (5 years to beyond 30 years) when the aperture correlation length is longer than 1/5 of the well distance, whereas a heterogeneous fracture behaves similar to a homogeneous one when the correlation length is much shorter than the well distance. Besides, the mean production life decreases with greater aperture standard deviation only when the correlation length is relatively long. Although flow channeling is inevitable, initial aperture fields and well locations that enable tortuous preferential paths tend to prolong heat production lives.
AU - Guo, Bin
A2 - Fu, Pengcheng
A3 - Hao, Yue
A4 - Peters, Catherine A.
A5 - Carrigan, Charles R.
DB - Open Energy Data Initiative (OEDI)
DP - Open EI | National Renewable Energy Laboratory
DO -
KW - geothermal
KW - thermal drawdown
KW - single fracture system
KW - thermomechanical coupling
KW - flow channeling
KW - reservoir simulation
KW - EGS
KW - engineered geothermal systems
KW - geothermics
KW - heat production
KW - single fracture
KW - thermomechanical
LA - English
DA - 2015/11/15
PY - 2015
PB - Lawrence Livermore National Laboratory
T1 - Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS
UR - https://data.openei.org/submissions/6891
ER -
Guo, Bin, et al. Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS. Lawrence Livermore National Laboratory, 15 November, 2015, GDR. https://gdr.openei.org/submissions/655.
Guo, B., Fu, P., Hao, Y., Peters, C., & Carrigan, C. (2015). Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS. [Data set]. GDR. Lawrence Livermore National Laboratory. https://gdr.openei.org/submissions/655
Guo, Bin, Pengcheng Fu, Yue Hao, Catherine A. Peters, and Charles R. Carrigan. Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS. Lawrence Livermore National Laboratory, November, 15, 2015. Distributed by GDR. https://gdr.openei.org/submissions/655
@misc{OEDI_Dataset_6891,
title = {Thermal Drawdown-Induced Flow Channeling in a Single Fracture in EGS},
author = {Guo, Bin and Fu, Pengcheng and Hao, Yue and Peters, Catherine A. and Carrigan, Charles R.},
abstractNote = {The evolution of flow pattern along a single fracture and its effects on heat production is a fundamental problem in the assessments of engineered geothermal systems (EGS). The channelized flow pattern associated with ubiquitous heterogeneity in fracture aperture distribution causes non-uniform temperature decrease in the rock body, which makes the flow increasingly concentrated into some preferential paths through the action of thermal stress. This mechanism may cause rapid heat production deterioration of EGS reservoirs.
In this study, we investigated the effects of aperture heterogeneity on flow pattern evolution in a single fracture in a low-permeability crystalline formation. We developed a numerical model on the platform of GEOS to simulate the coupled thermo-hydro-mechanical processes in a penny-shaped fracture accessed via an injection well and a production well. We find that aperture heterogeneity generally exacerbates flow channeling and reservoir performance generally decreases with longer correlation length of aperture field. The expected production life is highly variable (5 years to beyond 30 years) when the aperture correlation length is longer than 1/5 of the well distance, whereas a heterogeneous fracture behaves similar to a homogeneous one when the correlation length is much shorter than the well distance. Besides, the mean production life decreases with greater aperture standard deviation only when the correlation length is relatively long. Although flow channeling is inevitable, initial aperture fields and well locations that enable tortuous preferential paths tend to prolong heat production lives.
},
url = {https://gdr.openei.org/submissions/655},
year = {2015},
howpublished = {GDR, Lawrence Livermore National Laboratory, https://gdr.openei.org/submissions/655},
note = {Accessed: 2025-05-04}
}
Details
Data from Nov 15, 2015
Last updated Aug 11, 2017
Submitted Nov 26, 2015
Organization
Lawrence Livermore National Laboratory
Contact
Charles Carrigan
925.422.3941
Authors
Original Source
https://gdr.openei.org/submissions/655Research Areas
Keywords
geothermal, thermal drawdown, single fracture system, thermomechanical coupling, flow channeling, reservoir simulation, EGS, engineered geothermal systems, geothermics, heat production, single fracture, thermomechanicalDOE Project Details
Project Name Validation of EGS Feasibility and Explosive Fracturing Techniques
Project Lead Elisabet Metcalfe
Project Number FY15 AOP 1.3.2.4