Mechanical stress interference, or stress shadowing, refers to the change in stresses that occurs in the vicinity of hydraulic fractures. Because stress shadowing is ubiquitous in unconventional reservoirs, it greatly impacts completion design and field development strategies. Since it relates directly to the physical characteristics of the induced fracture network, it carries tremendous potential for fracture diagnostics.
Through the integrated interpretation of shut-in pressure escalation during multi-stage frac operations and offset-well poroelastic responses in two field cases, we illustrate the simplicity and affordability of novel stress-shadowing diagnostic methods to characterize induced-fracture dimensions and to inform important aspects of unconventional field development design. The key advantages compared to more intrusive diagnostic methods is the ability to scale up and test a large subset of wells and the reduction of the time to insight. Indeed, we were able to identify under-stimulated regions of the reservoir and to recommend a reduction in well spacing shortly after completion operations.