Mechanisms for the Generation of Complex Fracture Networks: Observations From Slant Core, Analog Models, and Outcrop

We use observations of hydraulic fractures in core, outcrop attributes natural fractures, and analogue models, to address how fracture networks evolve. A slant core from the Wolfcamp Formation—an unconventional shale hydrocarbon reservoir Permian Basin West Texas—collected within 18 m 30 two hydraulically stimulated horizontal wells, provided an opportunity examine directly. In approximately 183 309 calcite-sealed opening-mode 375 were identified. Many show complex morphology, including twist-hackle segmentation, diversion, bifurcation; these structures most commonly develop at lithological bed boundaries mechanical heterogeneities such as concretions. An bed-parallel pavements Cretaceous Boquillas Formation Texas contains that likely formed by fracturing. Fracture traces provide evidence are typically associated with preexisting stylolites. laboratory study fracturing 33 synthetic blocks gypsum hydrostone revealed steps, diversions, twist hackles, multiple overlapping together information on growth directions. These complexities network dominantly nucleated inclusions used simulate pre-existing a result heterogeneity introduced wellbore perforations. Collectively, our results produced self-sourced strata. Mechanical stratigraphic other enhance complexity through processes bifurcation. create strands, resulting increased number over those initiated, thereby increasing total surface area. Our provides insight into propagation, has applications for evaluation, completion, production, modeling reservoirs.