It is probably just an artist's impression of what running cracks might look like, based erroneously on lightning in the atmosphere.miraboreasu said:
The branching at the end of a fracture in fracking occurs due to the heterogeneous nature of the rock formation. Variations in rock properties, such as density, porosity, and pre-existing fractures, cause the main fracture to split into multiple branches as it propagates.
Fluid pressure plays a critical role in fracture branching. High-pressure fluid injection can cause the fracture to propagate more rapidly and with greater force, leading to increased likelihood of branching. The pressure differential at the fracture tip can cause the rock to split in multiple directions.
Natural fractures and faults within the rock formation can significantly influence fracture branching. When a hydraulic fracture intersects these natural discontinuities, the path of least resistance may change, causing the fracture to branch out along these pre-existing weaknesses.
The type of rock greatly affects fracture branching. Rocks with high brittleness, such as shale, are more likely to exhibit branching due to their tendency to crack under stress. Conversely, more ductile rocks may show less branching because they can deform more before fracturing.
While it is challenging to fully control or predict fracture branching, advanced modeling techniques and real-time monitoring can help anticipate fracture behavior. By understanding the geological conditions and using precise fluid injection techniques, engineers can better manage and influence the fracture network.