Abstract

This presentation is a continuation of an Energen study comparing the fracture system dynamics of 3 horizontal wellbores from 3 horizons (Spraberry, Upper and Middle Wolfcamp) in the Midland Basin. In this presentation, we integrate geomechanical properties with detailed characteristics of the natural fracture and bedding features acquired from borehole image logs. This data integration is used to identify change in rock properties and determine which fractures in each lateral are prone to shear failure, i.e. critically stressed under the present-day stress field. Changes in minerology, clay content and the amount of deformed bedding influences the stiffness of the rock units and these variations can influence variations in natural fracture observed in the image log data. Meanwhile, critically stressed fractures are more flow-conductive and hence, readily reactivated upon application of hydraulic stimulation pressure. As critically stressed fractures are controlled by stress anisotropy, their location and intensity directly impacts dispersal of the fracking treatment in the vicinity of the borehole, the pressure transmission along the vertical direction (i.e. frack-growth), and ultimately, the Stimulated Reservoir Volume profile. Therefore, knowing where the different fracture types are and the geomechanical characteristics along the lateral can improve completion design and well spacing decision.