Rocks with parallel single-direction fractures have faster rock velocities parallel to the fracture direction versus a slower velocity in a perpendicular direction 'across' the fractures. The slowness depends on the fracture density, fracture aperture, and the fluid content within the fracture. Knowing where you have single-direction fractures and their orientation enables you to plan where to place your horizontal wells and in which orientation they should be drilled.
Dual-direction fractures will usually result in the highest producing wells because of the fracture connectivity. The anisotropic behavior of this type of fracture is more complicated to discriminate because the signature of these fractures approaches the isotropic rock case.
ION has extensive experience in fracture detection in tight sands, shale plays, and carbonate reservoirs throughout the world. Experienced use of P-wave AZIM technology and shear-wave splitting techniques from full-wave data can provide optimal fracture detection tools to optimize drilling plans.