Tiny AEC sensors are now sophisticated enough to report downhole temperatures and pressures under real-world conditions. Three different millimeter-scale microfabricated sensor platforms have been developed to collect time stamped critical data (pressure, temperature, pH, etc.) in harsh environments (e.g. 7,500 psi and 125C). Applications include flow assurance, wellbore integrity, hydraulic fracture and reservoir characterization, and pipeline surveillance. They can report back using wireless and/or optical data transfer methods, and their battery life has been extended exponentially to one week. One member company reported that it is testing AEC sensors to report data from within flowlines, both while attached to pipeline pigs and flowing with product as a buoyant sphere. Another member is recording downhole temperatures before cementing well casing, and is also testing their use in determining downhole cement integrity. A third member organization hopes to eventually create a network of these sensors underground, using them to report broad subsurface conditions in real time.
AEC’s microsensor platforms
AEC contrast agents help to map fracture patterns, fluid flow, and reservoir extent. Contrast Agents (passive, tracer-like molecules or nanoparticles having augmented electromagnetic, acoustic, or other discernible properties) are being deployed to create precise reservoir imaging of hydraulic fracture networks. Nano-scale electromagnetic proppants were recently validated as effective at mapping the extent of a hydraulic fracturing operation during a field test at the AEC’s Intermediate Scale Field Test Lab near Devine, Texas. The AEC is currently testing the use of contrast agents to track subsurface physiochemical properties using external and remote monitoring stations. Another member is testing contrast agents for use in fracture visualization, and plans to place electromagnetic sensors in casing collars to receive data from downhole contrast agents.
AEC payload delivery systems have been developed to transport various chemicals within tiny capsules that open and release their cargoes under pre-determined conditions, such as higher temperatures. The AEC has developed a number of novel core-shell payload delivery systems. These are applicable to many cargo types, both for deep reservoir and near wellbore apps, including: encapsulation of viscosifiers (polymers and cross linkers) for permeability control for enhanced oil recovery (EOR), and acid encapsulation to reduce damage to wellbore during acid stimulation and for wellbore remediation. One AEC member continues extensive testing of AEC payload delivery nano-capsules to transport acid deep into a well. Another application would be to use the acid-carrying capsules to remove mudcake from sidewalls. The company continues its experimentation with the nano-capsules as it moves closer to developing the technology to the point of commercialization.
The founding members’ vision for the Advanced Energy Consortium (AEC) was to develop micro- and nano-scale sensors that could collect higher-resolution data at distances farther than existing technologies in order to map the physical, chemical, and spatial characteristics of the rocks, minerals, faults, and fluids in the wellbore and interwell space. Given the heterogeneous nature of oilfield rocks and fluids, and the harshness of the environment—including high temperatures, high pressures, small pore spaces (30 nm to 10 µm), high salinity, and varied pH conditions—this vision is challenging and exciting.
In the decade since its inception, the Advanced Energy Consortium (AEC) has progressed nanotechnology from fundamental to applied research and is now targeting commercial applications such as precise reservoir imaging of hydraulic fracture networks using electromagnetic contrast agents; microsensor data logging in wellbores, pipelines, and other infrastructure; and targeted payload deliveries in a host of environments.
The AEC and its members are currently advancing plans for multiple field-scale demonstrations of the current nanotechnologies and prioritizing near-term research. With the commitment of members to recruit additional partners for commercial prototype testing, excitement is building regarding the upcoming commercial availability of AEC technology. Recently, an invitation-only event was conducted to invite suppliers and service companies to evaluate and participate in this lucrative commercial opportunity - the foundation for creating the AEC’s future research strategy, which has potential applications in diverse fields such as conventional and unconventional oil and gas, geothermal energy, energy resource and waste storage, and environmental monitoring.
Guest organizations at the recent AEC meeting were thoroughly impressed with the level of nanotechnology innovation presented, and there was keen interest in joining the consortium. It was stressed during discussions that AEC applications are being considered outside of the oil and gas industry, and include potential use of the nano-technology in geothermal systems, to map aquifers, in mining operations, and in waste disposal monitoring, among other concepts. Membership is open to any organization with an interest in pursuing this fascinating research and development.
AEC program leader and principal investigator