Research Article
Mechanisms of Crack Initiation and Propagation in Dense Linear Multihole Directional Hydraulic Fracturing
Figure 12
Crack initiation and propagation modes of directional hydraulic fracturing controlled by dense linear multihole drilling. (a) Three modes of crack initiation of directional hydraulic fracturing controlled by dense linear multihole drilling. (A) Initiation along the borehole line. (B) Bidirectional initiation. (C) Initiation perpendicular to σ3. (b) Five modes of crack propagation of directional hydraulic fracturing controlled by dense linear multihole drilling. (A) Propagation along borehole line. (B) Propagation forming ladder pattern. (C) Propagation forming S-shaped pattern. (D) Bidirectional propagation. (E) Propagation perpendicular to σ3.
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