Details
| Original language | English |
|---|---|
| Article number | 105306 |
| Journal | Engineering Geology |
| Volume | 266 |
| Early online date | 29 Nov 2019 |
| Publication status | Published - 5 Mar 2020 |
Abstract
In the hydraulic fracturing of natural rocks, understanding and predicting crack penetrations into the neighboring layers is crucial and relevant in terms of cost-efficiency in engineering and environmental protection. This study constitutes a phase field framework to examine hydraulic fracture propagation in naturally-layered porous media. Biot's poroelasticity theory is used to couple the displacement and flow field, while a phase field method helps characterize fracture growth behavior. Additional fracture criteria are not required and fracture propagation is governed by the equation of phase field evolution. Thus, penetration criteria are not required when hydraulic fractures reach the material interfaces. The phase field method is implemented within a staggered scheme that sequentially solves the displacement, phase field, and fluid pressure. We consider the soft-to-stiff and the stiff-to-soft configurations, where the layer interface exhibits different inclination angles θ. Penetration, singly-deflected, and doubly-deflected fracture scenarios can be predicted by our simulations. In the soft-to-stiff configuration, θ=0° exhibits penetration or symmetrical doubly-deflected scenarios, and θ=15° exhibits singly-deflected or asymmetric doubly-deflected scenarios. Only the singly-deflected scenario is obtained for θ=30°. In the stiff-to-soft configuration, only the penetration scenario is obtained with widening fractures when hydraulic fractures penetrate into the soft layer.
Keywords
- Cap layer, Hydraulic fracturing, Numerical simulation, Phase field, Reservoir layer, Staggered scheme
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geotechnical Engineering and Engineering Geology
- Earth and Planetary Sciences(all)
- Geology
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In: Engineering Geology, Vol. 266, 105306, 05.03.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - On the hydraulic fracturing in naturally-layered porous media using the phase field method
AU - Zhuang, Xiaoying
AU - Zhou, Shuwei
AU - Sheng, Mao
AU - Li, Gengsheng
N1 - Funding Information: The authors gratefully acknowledge the financial support provided by the Natural Science Foundation of China (51474157), and the RISE-project BESTOFRAC (734370).
PY - 2020/3/5
Y1 - 2020/3/5
N2 - In the hydraulic fracturing of natural rocks, understanding and predicting crack penetrations into the neighboring layers is crucial and relevant in terms of cost-efficiency in engineering and environmental protection. This study constitutes a phase field framework to examine hydraulic fracture propagation in naturally-layered porous media. Biot's poroelasticity theory is used to couple the displacement and flow field, while a phase field method helps characterize fracture growth behavior. Additional fracture criteria are not required and fracture propagation is governed by the equation of phase field evolution. Thus, penetration criteria are not required when hydraulic fractures reach the material interfaces. The phase field method is implemented within a staggered scheme that sequentially solves the displacement, phase field, and fluid pressure. We consider the soft-to-stiff and the stiff-to-soft configurations, where the layer interface exhibits different inclination angles θ. Penetration, singly-deflected, and doubly-deflected fracture scenarios can be predicted by our simulations. In the soft-to-stiff configuration, θ=0° exhibits penetration or symmetrical doubly-deflected scenarios, and θ=15° exhibits singly-deflected or asymmetric doubly-deflected scenarios. Only the singly-deflected scenario is obtained for θ=30°. In the stiff-to-soft configuration, only the penetration scenario is obtained with widening fractures when hydraulic fractures penetrate into the soft layer.
AB - In the hydraulic fracturing of natural rocks, understanding and predicting crack penetrations into the neighboring layers is crucial and relevant in terms of cost-efficiency in engineering and environmental protection. This study constitutes a phase field framework to examine hydraulic fracture propagation in naturally-layered porous media. Biot's poroelasticity theory is used to couple the displacement and flow field, while a phase field method helps characterize fracture growth behavior. Additional fracture criteria are not required and fracture propagation is governed by the equation of phase field evolution. Thus, penetration criteria are not required when hydraulic fractures reach the material interfaces. The phase field method is implemented within a staggered scheme that sequentially solves the displacement, phase field, and fluid pressure. We consider the soft-to-stiff and the stiff-to-soft configurations, where the layer interface exhibits different inclination angles θ. Penetration, singly-deflected, and doubly-deflected fracture scenarios can be predicted by our simulations. In the soft-to-stiff configuration, θ=0° exhibits penetration or symmetrical doubly-deflected scenarios, and θ=15° exhibits singly-deflected or asymmetric doubly-deflected scenarios. Only the singly-deflected scenario is obtained for θ=30°. In the stiff-to-soft configuration, only the penetration scenario is obtained with widening fractures when hydraulic fractures penetrate into the soft layer.
KW - Cap layer
KW - Hydraulic fracturing
KW - Numerical simulation
KW - Phase field
KW - Reservoir layer
KW - Staggered scheme
UR - http://www.scopus.com/inward/record.url?scp=85076472636&partnerID=8YFLogxK
U2 - 10.1016/j.enggeo.2019.105306
DO - 10.1016/j.enggeo.2019.105306
M3 - Article
AN - SCOPUS:85076472636
VL - 266
JO - Engineering Geology
JF - Engineering Geology
SN - 0013-7952
M1 - 105306
ER -