Horn River Basin: A Study of the Behavior of Frac Barriers in a Thick Shale Package Using the Integration of Microseismic, Geomechanics and LogAnalysis

摘要

Horn River Group (HRG) shales are prime exploration targets. The shales form a 200m thickpackage of over-pressured, organic rich, siliceous mudrocks found at drilling depths between2400-2700m. The gross thickness of the shale interval and the observed frac barriers within theshale package present a challenge for maximizing the stimulated rock volume when completingwells. Within Devon Canada, an exploration program was designed to evaluate reservoircomplexity and heterogeneity, the ultimate goal being to optimize horizontal, vertical and lateralwell placement while balancing recovery factor and capital costs.Core and log data from vertical wells were analyzed to target optimal horizontal drilling zonesfor hydraulic fracture initiation and ease of drilling. Geomechanical log analysis supports theobservation made from microseismic data that frac height growth through the frac barriers in theshale package happens preferentially depending upon the direction from which the fracture wasinitiated.