The geomechanics associated with oil and gas reservoirs has always been an issue even in vertical wells. However, now that seventy percent of all wells and nearly one hundred percent of wells in unconventional reservoirs are drilled horizontally it has become an even more important issue. After all, horizontal wells have become the industry standard for unconventional and tight formation oil and gas reservoirs. Why are the geomechanics and stress state important? How does the geomechanics impact the well completion and stimulation? What role does geomechanics play with regard to the creation of complexity? How can an understanding of the geomechanics be used to increase the profitability of an unconventional resource? These are just a few questions to be addressed during this presentation.
This presentation will focus on some of the key elements of the reservoir such as geomechanics and permeability and how they apply to horizontal well completions and stimulation practices. The stress state will be addressed to understand the effect of hoop stresses on breakdown pressures and determine the impact on completion and stimulation staging. It will be used to assess reservoir complexity and completion practices such as simul-frac’s, zipper frac’s, bashing, and natural fissure behavior. Optimization studies will be shown and used to highlight the importance of lateral length, number of fractures, inter-fracture distance, fracture half-length, and fracture conductivity. These results will be used to discuss the various completion choices such as cased and cemented, open hole with external casing packers, and open hole “pump and pray” techniques.