Fractured reservoirs, fault hydraulic behavior and mechanical instability

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All natural subsurface reservoirs are characterized by faults and natural fractures that influence fluid circulation. Depending on the tectonic evolution of a sedimentary basin, the state of stress and prevailing pressure, faults and fractures may be sealing or leaking. Because reservoir fluids may contain hydrocarbons and can transport heat and hazardous chemicals, the transmissivity of faults and fractures have important consequences for petroleum exploration, geothermal energy, CO2 storage and waste-disposal. Additionally, fault instability during depletion or injection operations may result in induced seismicity and topseal breaching.    I propose to investigate the influence of natural and hydraulic fractures and faults on the distribution and state of stresses, pressure regimes, and permeability of flow units. The fault architecture, sealing capacity and shear slip potential of faults will be analyzed, and the significance of fault relay zones and fracture sets examined. Research will involve structural studies of outcrops, interpretation of geophysical data and coupled reservoir geomechanical numerical simulations. HQP will be provided with the opportunity to undertake field- and laboratory-based geological and geophysical investigations. My goal is to build predictive models for faults as barriers or channels in subsurface reservoirs and for fault reactivation potential under the in situ stress and pore pressure changes. Realization of the proposed research will be applied to sedimentary basins at different tectonic settings (extensional, strike-slip and compressional regime), including the conventional Volve oil field (North Sea) and unconventional plays of the McCully gas field (New Brunswick), Fox Creek area (West-central Alberta) and Horn River Basin (NE British Columbia).    Developing expertise in fault and fracture detection, fault hydraulic behavior and mechanical instability in the subsurface is important both for increasing efficiency of hydrocarbon exploration and extraction and for safety of hydraulic fracturing operations in unconventional reservoirs. Potential upward fluid migration to shallow aquifers and risk of induced seismicity related to unconventional resource development in the McCully field, Fox Creek area and Horn River Basin represent major environmental concerns for these regions. The proposed coupled reservoir-geomechanical modeling and sensitivity analysis on the relationship of fault transmissivity and mechanical instability caused by injection operations will help to mitigate potential environmental impacts of hydrocarbon development in active production areas.