Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering

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We investigate the flow-channeling phenomenon caused by thermal drawdown in fractured geothermal reservoirs. A discrete fracture network-based, fully coupled thermal "hydrological" mechanical simulator is used to study the interactions between fluid flow, temperature change, and the associated rock deformation. The responses of a number of randomly generated 2D fracture networks that represent a variety of reservoir characteristics are simulated with various injection-production well distances. We find that flow channeling, namely flow concentration in cooled zones, is the inevitable fate of all the scenarios evaluated. We also identify a secondary geomechanical mechanism caused by the anisotropy in thermal stress that counteracts the primary mechanism of flow channeling. This new mechanism tends, to some extent, to result in a more diffuse flow distribution, although it is generally not strong enough to completely reverse flow channeling. We find that fracture intensity substantially affects the overall hydraulic impedance of the reservoir but increasing fracture intensity generally does not improve heat production performance. Increasing the injection-production well separation appears to be an effective means to prolong the production life of a reservoir.

DOI: 10.1007/s00603-015-0776-0.

Citation Formats

Lawrence Livermore National Laboratory. (2015). Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering [data set]. Retrieved from https://gdr.openei.org/submissions/654.
Export Citation to RIS
Fu, Pengcheng, Carrigan, Charles R., Walsh, Stuart D. C., and Hao, Yue. Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering. United States: N.p., 15 Nov, 2015. Web. https://gdr.openei.org/submissions/654.
Fu, Pengcheng, Carrigan, Charles R., Walsh, Stuart D. C., & Hao, Yue. Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering. United States. https://gdr.openei.org/submissions/654
Fu, Pengcheng, Carrigan, Charles R., Walsh, Stuart D. C., and Hao, Yue. 2015. "Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering". United States. https://gdr.openei.org/submissions/654.
@div{oedi_654, title = {Thermal Drawdown Induced Flow Channeling in Fractured Geothermal Reservoirs: Rock Mechanics and Rock Engineering}, author = {Fu, Pengcheng, Carrigan, Charles R., Walsh, Stuart D. C., and Hao, Yue.}, abstractNote = {We investigate the flow-channeling phenomenon caused by thermal drawdown in fractured geothermal reservoirs. A discrete fracture network-based, fully coupled thermal "hydrological" mechanical simulator is used to study the interactions between fluid flow, temperature change, and the associated rock deformation. The responses of a number of randomly generated 2D fracture networks that represent a variety of reservoir characteristics are simulated with various injection-production well distances. We find that flow channeling, namely flow concentration in cooled zones, is the inevitable fate of all the scenarios evaluated. We also identify a secondary geomechanical mechanism caused by the anisotropy in thermal stress that counteracts the primary mechanism of flow channeling. This new mechanism tends, to some extent, to result in a more diffuse flow distribution, although it is generally not strong enough to completely reverse flow channeling. We find that fracture intensity substantially affects the overall hydraulic impedance of the reservoir but increasing fracture intensity generally does not improve heat production performance. Increasing the injection-production well separation appears to be an effective means to prolong the production life of a reservoir.

DOI: 10.1007/s00603-015-0776-0.
}, doi = {}, url = {https://gdr.openei.org/submissions/654}, journal = {}, number = , volume = , place = {United States}, year = {2015}, month = {11}}

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

Pengcheng Fu

Lawrence Livermore National Laboratory

Charles R. Carrigan

Lawrence Livermore National Laboratory

Stuart D. C. Walsh

Lawrence Livermore National Laboratory

Yue Hao

Lawrence Livermore National Laboratory

DOE Project Details

Project Name Validation of EGS Feasibility and Explosive Fracturing Techniques

Project Lead Elisabet Metcalfe

Project Number FY15 AOP 1.3.2.4

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