TY - JOUR
T1 - Numerical simulation of stress field reorientation in multi-fractures
AU - Deng, Yan
AU - Mu, Shuxing
AU - Liu, Yuxuan
AU - Mu, Na
AU - Guo, Jianchun
AU - Zeng, Jie
AU - Yu, Hao
N1 - Funding Information:
This study was financially supported by the National Natural Science Foundation of China (Nos. U23B6004 and 52004225).
Publisher Copyright:
© 2024, The Author(s).
PY - 2024/12
Y1 - 2024/12
N2 - Understanding the stress state caused by a subsequent failure is crucial for successful refracturing. However, there are many differences between the stress reorientation phenomena of a multi-fracture horizontal well and that of a single fracture in a vertical well, including the interaction of multi-fractures. These factors can lead to a change in the stress field of multiple fractures, which is more complex than that of a single fracture. In this paper, based on the elastic theory of porous media and the mechanism of fluid–structure interaction, a finite element numerical model of multi-fracture stress fields is established. The net pressure loaded on the fracture wall was corrected using the fracture line model, which was solved using the separated coupling method with a staggered strategy, and a full coupling simulation of fluid flow and rock deformation was achieved. The results showed that with an increase in production time, the stress reorientation area around the fracture and at both ends first increased at a faster rate, then slowly decreased, and finally disappeared,indicating an optimal refracturing time window. This suggests that the greater the number of fractures, the greater the fracture inclination and fracture bending degree, and the more unfavorable it is for the formation and maintenance of the stress reorientation area near the fracture and at both ends of the fracture. The reorientation of the stress field between horizontal wells may lead to the fracture of the infill wells, causing bending and propagation towards the pressure-depletion area, thus reducing productivity.
AB - Understanding the stress state caused by a subsequent failure is crucial for successful refracturing. However, there are many differences between the stress reorientation phenomena of a multi-fracture horizontal well and that of a single fracture in a vertical well, including the interaction of multi-fractures. These factors can lead to a change in the stress field of multiple fractures, which is more complex than that of a single fracture. In this paper, based on the elastic theory of porous media and the mechanism of fluid–structure interaction, a finite element numerical model of multi-fracture stress fields is established. The net pressure loaded on the fracture wall was corrected using the fracture line model, which was solved using the separated coupling method with a staggered strategy, and a full coupling simulation of fluid flow and rock deformation was achieved. The results showed that with an increase in production time, the stress reorientation area around the fracture and at both ends first increased at a faster rate, then slowly decreased, and finally disappeared,indicating an optimal refracturing time window. This suggests that the greater the number of fractures, the greater the fracture inclination and fracture bending degree, and the more unfavorable it is for the formation and maintenance of the stress reorientation area near the fracture and at both ends of the fracture. The reorientation of the stress field between horizontal wells may lead to the fracture of the infill wells, causing bending and propagation towards the pressure-depletion area, thus reducing productivity.
KW - Fluid–structure interaction
KW - Horizontal well
KW - Refracturing
KW - Staggered strategy
KW - Stress reorientation
UR - http://www.scopus.com/inward/record.url?scp=85183594089&partnerID=8YFLogxK
U2 - 10.1007/s40948-024-00745-1
DO - 10.1007/s40948-024-00745-1
M3 - Article
AN - SCOPUS:85183594089
SN - 2363-8419
VL - 10
JO - Geomechanics and Geophysics for Geo-Energy and Geo-Resources
JF - Geomechanics and Geophysics for Geo-Energy and Geo-Resources
IS - 1
M1 - 36
ER -