Channel and Energy Modeling for Self-Contained Wireless Sensor Networks in Oil Reservoirs

The real-time and in-situ monitoring capability in oil reservoirs is highly desired to increase the current recovery factor of crude oil and natural gas. To this end, the wireless sensor networks (WSNs) are envisioned to be deployed deep inside oil reservoirs to collect and report the physical and chemical information in real time. However, none of the existing wireless communication and networking technologies can support WSNs in oil reservoirs due to the very challenging environment and the extremely small device size. To address the problem, this paper proposes a new self-contained micro wireless sensor network framework based on the Magnetic Induction (MI) technique, which can enable the real-time and in-situ monitoring in oil reservoirs. Rigorous analytical models are developed to characterize the oil reservoir channel for both MI communication and energy transfer, which confirm the feasibility of the proposed self-contained sensor network framework. To enhance the system efficiency and reliability, high-permeability proppants are injected in the hydraulic fracture to increase mutual induction; while the tri-directional MI coil antenna is designed to achieve omnidirectional coverage. The theoretical models and numerical results are validated by the widely used finite element simulation software COMSOL Multiphysics.