Fractured reservoirs, fault hydraulic behavior and mechanical instability

所有天然地下油藏都以影响流体循环的断层和天然裂缝为特征。根据沉积盆地的构造演化、应力状态和当时的压力，断层和裂缝可能是封闭的或泄漏的。由于储层流体可能含有碳氢化合物，并可以输送热量和危险化学品，因此断层和裂缝的传导性对石油勘探、地热能、二氧化碳储存和废物处理具有重要影响。此外，衰竭或注水作业过程中的断层不稳定性可能导致诱发地震活动和顶盖破裂。我建议调查天然和水力裂缝和断层对流动单元的应力分布和状态、压力状况和渗透率的影响。将分析断层结构、断层封闭性和断层的剪切滑移潜力，并研究断层继电器带和断裂组的意义。研究将涉及露头构造研究、地球物理数据解释和油藏地质力学数值模拟耦合。总部基地将有机会进行实地和实验室的地质和地球物理调查。我的目标是建立地下储集层中断层作为屏障或通道的预测模型，以及地应力和孔隙压力变化下的断层再激活潜力的预测模型。拟议研究的实现将应用于不同构造环境(伸展、走滑和挤压体制)的沉积盆地，包括常规Volve油田(北海)和McCully气田(新不伦瑞克)、Fox Creek地区(艾伯塔省中西部)和Horn River盆地(不列颠哥伦比亚省东北部)的非常规盆地。除了发展断层和裂缝检测方面的专业知识外，地下断层的水力行为和机械不稳定性对于提高油气勘探和开采的效率以及非常规油藏水力压裂作业的安全都是重要的。麦卡利油田、福克斯克里克地区和霍恩河流域的非常规资源开发可能导致流体向上向浅含水层迁移，以及诱发地震活动的风险，这些都是这些地区的主要环境问题。建立油藏-地质力学耦合模型，对注水作业引起的断层导水率与力学不稳定性的关系进行敏感性分析，将有助于缓解活跃产区油气开发对环境的潜在影响。

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.