Fracturing of shales via in-situ pore fluid pressurization by electromagnetic heating

该研究项目涉及非常规石油开采，重点是新技术，以限制从含有夹层页岩的非均质油砂油藏中就地采油时用水。夹层页岩是散布在油砂储层内的大型侧向粘土状侵入体，其阻碍了SAGD（蒸汽辅助重力泄油）中蒸汽的传播，从而阻碍了石油生产。由于材料的低渗透性，通过蒸汽注入引起页岩的破坏将需要高压和大量的水使用。相反，页岩中的水通过电磁（EM）波的穿透而被热激发，就像在家用微波炉中烹饪食物一样。 该研究的主要目的是开发一种使用电磁原位加热方案压裂页岩和邻近油砂的方法，该方案引起孔隙流体的热加压并释放粘土颗粒中的未结合水。这将通过以下综合方法实现，包括实验室实验，本构和数值建模工作：（1）在宏观、中观和微观三个尺度上理解页岩在电磁波存在下的热-孔隙-力学行为，（2）实验室三轴测试，以再现经由内部探针经受EM波的页岩样品中的原位孔隙流体加压，以及（3）压裂现象的多尺度数值模拟，并将其实施到计算代码中，以在储层尺度上模拟该过程。将使用页岩的颗粒描述，其中纳米级的堆叠粘土片晶形成亚微米粘土聚集体颗粒，这些颗粒通过短程力和长程力相互作用。 拟议的研究将与卡尔加里的几个主要行业合作伙伴密切合作，即计算机建模集团有限公司，帝国石油有限公司，赫斯基能源公司（Husky Energy）和BitCan Inc. CMG油藏模拟基金会也承诺为这一战略项目提供财政支持。

The research project relates to unconventional oil extraction with a focus on new technologies to limit the use of water in the in-situ recovery of oil from heterogeneous oil sand reservoirs containing interbedded shales. Interbedded shales are large lateral clay-like intrusions interspersed within the oil sand reservoir that hinder the propagation of steam in SAGD (Steam Assisted Gravity Drainage), and hence oil production. Inducing the failure of shale by steam injection would require high pressures and considerable water usage because of low permeability of the material. Instead, the water within the shale is thermally excited by penetration of an electromagnetic (EM) wave just as when cooking food in a domestic microwave oven. The main objective of the research is to develop a method for fracturing the shales and adjacent oil sand using an electromagnetic in-situ heating scheme that induces thermal pressurization of the pore fluid and frees up the unbound water from the clay particles. This will be achieved following an integrated approach involving lab experimental, constitutive and numerical modelling works through: (1) Understanding of thermo-poro-mechanical behaviour of shales in the presence of electromagnetic waves at three scales, i.e. macro-, meso- and micro-scales, (2) Lab triaxial testing in order to reproduce the in-situ pore fluid pressurization in a shale sample subjected to EM wave via an internal probe, and (3) Multi-scale numerical modelling of the fracturing phenomenon and implementation into a computational code to model the process at the reservoir scale. A granular description of shale will be used in which stacked clay platelets at the nano-scale form sub-micron clay aggregates grains that interact with each other through both short- and long-range forces. The proposed research will be undertaken in close collaboration with several leading industry partners in Calgary, namely, Computer Modelling Group Ltd., Imperial Oil Ltd., Husky Energy, and BitCan Inc. CMG Reservoir Simulation Foundation has also committed to financially support this strategic project.