Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Initiation Pressure and Fracture Path of Near-Field Symmetric Pre-cut Hydraulic Fracturing
To reduce the use of explosives in the metal-mining process, a pre-cut hydraulic fracturing technology has been proposed for directional pretreatment of rock strata, in which the initiation pressure and the fracture propagation path are crucial aspects of the fracturing pretreatment. In this study, the stress distribution in the near-field metal ore body of the upward horizontal filling mining method was calculated. At mining workface l = 0, σy > σx = 0, as the horizontal distance l increases from the workface and σx first increases and then decreases, causing σy to gradually decrease. In addition, l0 exists such that 0 < l < l0 and σy > σx, indicating that the vertical stress is greater than the horizontal stress. Based on the stress distribution environment, a symmetrical pre-cut hydraulic fracturing mechanical model was established, and a method for calculating the initiation pressure was provided. The correctness of the initiation pressure calculation method was verified through physical experiments and the experimental and calculated values are similar. Numerical simulations of fracture propagation paths in pre-cut hydraulic fracturing were conducted using the lattice method, which demonstrated that hydraulic fractures initiate along the pre-cut fractures and then differentiate into two hyperbolic-shaped major fractures symmetrically along the pre-cut fractures. Secondary fractures connect between the major fractures. As the angle between the pre-cut fractures and the minimum horizontal principal stress increases, the curvature of the main fractures decreases, and their extent of propagation along the pre-cut fractures increases, indicating better directional effects. Moreover, the number of secondary fractures increases, forming a more complex network of fractures, which is conducive to densely fracturing the target rock layer in a directional manner, enhancing permeability, and reducing the mechanical properties of the rock strata. With the increase in the maximum horizontal principal stress, the major fractures extending along the pre-cut fractures are suppressed and become shorter. The curvature of the hyperbolic-shaped major fractures decreases, and the number of secondary fractures is reduced, resulting in a less effective modification of the rock strata through pre-cut hydraulic fracturing.
Propose the use of Pre-cut hydraulic fracturing to replace explosive blasting in the mining of hard metal ore bodies.
Obtain a stress distribution model ahead of the working face in ore body mining and identify the stress distribution patterns.
Based on the stress distribution patterns, propose a calculation model for the initiation pressure with pre-cut hydraulic fracturing.
Based on the calculation model for the initiation pressure, determine the influence patterns with various parameters.
Utilize the lattice method to obtain the fracture propagation paths and influencing patterns under pre-cut hydraulic fracturing.
Initiation Pressure and Fracture Path of Near-Field Symmetric Pre-cut Hydraulic Fracturing
To reduce the use of explosives in the metal-mining process, a pre-cut hydraulic fracturing technology has been proposed for directional pretreatment of rock strata, in which the initiation pressure and the fracture propagation path are crucial aspects of the fracturing pretreatment. In this study, the stress distribution in the near-field metal ore body of the upward horizontal filling mining method was calculated. At mining workface l = 0, σy > σx = 0, as the horizontal distance l increases from the workface and σx first increases and then decreases, causing σy to gradually decrease. In addition, l0 exists such that 0 < l < l0 and σy > σx, indicating that the vertical stress is greater than the horizontal stress. Based on the stress distribution environment, a symmetrical pre-cut hydraulic fracturing mechanical model was established, and a method for calculating the initiation pressure was provided. The correctness of the initiation pressure calculation method was verified through physical experiments and the experimental and calculated values are similar. Numerical simulations of fracture propagation paths in pre-cut hydraulic fracturing were conducted using the lattice method, which demonstrated that hydraulic fractures initiate along the pre-cut fractures and then differentiate into two hyperbolic-shaped major fractures symmetrically along the pre-cut fractures. Secondary fractures connect between the major fractures. As the angle between the pre-cut fractures and the minimum horizontal principal stress increases, the curvature of the main fractures decreases, and their extent of propagation along the pre-cut fractures increases, indicating better directional effects. Moreover, the number of secondary fractures increases, forming a more complex network of fractures, which is conducive to densely fracturing the target rock layer in a directional manner, enhancing permeability, and reducing the mechanical properties of the rock strata. With the increase in the maximum horizontal principal stress, the major fractures extending along the pre-cut fractures are suppressed and become shorter. The curvature of the hyperbolic-shaped major fractures decreases, and the number of secondary fractures is reduced, resulting in a less effective modification of the rock strata through pre-cut hydraulic fracturing.
Propose the use of Pre-cut hydraulic fracturing to replace explosive blasting in the mining of hard metal ore bodies.
Obtain a stress distribution model ahead of the working face in ore body mining and identify the stress distribution patterns.
Based on the stress distribution patterns, propose a calculation model for the initiation pressure with pre-cut hydraulic fracturing.
Based on the calculation model for the initiation pressure, determine the influence patterns with various parameters.
Utilize the lattice method to obtain the fracture propagation paths and influencing patterns under pre-cut hydraulic fracturing.
Initiation Pressure and Fracture Path of Near-Field Symmetric Pre-cut Hydraulic Fracturing
Rock Mech Rock Eng
Yu, Qian (Autor:in) / Zhao, Yuemao (Autor:in) / Zhao, Xingdong (Autor:in) / Liu, Shuyuan (Autor:in) / Cong, Yu (Autor:in) / Li, Huaibin (Autor:in) / Zhu, Hongmo (Autor:in) / Jiang, Tianqi (Autor:in) / Cao, Juncai (Autor:in) / Zhang, Song (Autor:in)
Rock Mechanics and Rock Engineering ; 58 ; 1003-1020
01.01.2025
18 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Initiation Pressure and Fracture Path of Near-Field Symmetric Pre-cut Hydraulic Fracturing
| Springer Verlag | 2025
Hydraulic fracturing initiation in granite
| British Library Conference Proceedings | 1996
Fracture initiation and propagation in soft hydraulic fracturing of hot dry rock
| DOAJ | 2024
Hydraulic fracturing : a fracture mechanics approach
| TIBKAT | 1980
Hydraulic fracture orientation and pressure response during fracturing of producing wells
| British Library Conference Proceedings | 1994