Giovanni Grasselli

University of Toronto

Adding value to the energy industry through laboratory testing

The Montney Formation, a stratigraphic unit of Lower Triassic age in the Western Canadian Sedimentary Basin, is a major unconventional gas play in North America. The presence of bedding planes in the Montney makes the formation intrinsically anisotropic, with rock laminations strongly correlated to changes in hydrocarbon production. Understanding the geometry of the stimulated rock volume (SRV) created during hydraulic fracturing operations is fundamental in assessing their effectiveness and forecasting the production curve. Hydraulic fracturing experiments realized in the laboratory under reservoir stress conditions show that the majority of the SRV, approximately 90%, is comprised of parted bedding planes and reactivated natural fractures, and not by newly created bi-wing cracks as commonly assumed. In simpler words, bedding plane parting dominates SRV geometry, thus, it directly ties to how and from where the reservoir produces. Understanding the SRV geometry and estimating the strength of parted bedding planes can also help to explain processes such as casing deformation, induced seismicity, and frac hits (parent-child interactions).