Despite the past year’s increased volatility of oil prices, collapse of credit markets, and global economic downturn, 10 of the world’s leading oil and gas industry companies believe there is value in conducting shared precompetitive research on nanotechnologies for the oil and gas industry.

This image shows a graphene membrane surface characterization. (All images courtesy of AEC)

The Advanced Energy Consortium (AEC), managed by the Bureau of Economic Geology (BEG) at The University of Texas at Austin, is now completing its first year of work on 21 research programs. Formed in January 2008, the US $30 million consortium is directed by Scott W. Tinker and managed by a small bureau team including Jay Kipper, Sean Murphy, David Chapman, Carla Thomas, and retired Shell reservoir chemist Robert McNeil. AEC members, including BP America Inc., Baker Hughes Inc., ConocoPhillips, Halliburton Energy Services Inc., Marathon Oil Corp., Occidental Oil and Gas, Petrobras, Schlumberger, Shell, and Total, are researching micro- and nanotechnology applications for oil and gas E&P with an initial emphasis on the development of subsurface sensors. The founding members’ vision for AEC is to develop micro- and nanoscale sensors that can be injected into oil and gas well bores, migrate through the fractures and pores in the reservoir, and collect real-time instantaneous data regarding the physical, chemical, and spatial characteristics of the rocks, minerals, faults, and fluids from the interwell space, thereby “illuminating the reservoir.”

Over the course of the last two years, AEC member companies have evaluated more than 150 proposals, resulting in 34 funded research projects that encompass more than 25 North American, South American, and European research institutions and universities. Twenty-one of these research projects were launched in the first year of AEC’s formation, with an additional 13 recently funded.

Research programs

AEC’s research programs focus on four technology disciplines.

On the left side is an optical microscope image of three microchannels from a microfluidic chip. At right, the distance the particle is pulled from the center of the optical tweezer laser spot (“extension”) is shown as a function of time.

Contrast enhancing nanoagents are nanoparticle-based threshold-level detecting sensors that are specifically designed to have an affinity for a desired target and are imaged remotely. Exploiting the unique chemical and physical properties that some compounds exhibit at the nanoscale, these contrast agents show promise for enhancing the response and/or improving the resolution of existing remote sensing technologies for oil and gas such as seismic or electromagnetic sensors. This is an exciting area which may have near-term practical applications.

Nanomaterial sensors are molecular and material-based sensors, most of which require retrieval and interrogation, which exhibit a detectable state change when exposed to discrete or threshold level variations in reservoir physical or chemical conditions.

Micro/nano electronic devices measure reservoir properties, store or communicate data back to the well bore, and can demonstrate a path toward further miniaturization.

Fundamental research on nanomaterial transport and fluid flows enables transport within the reservoir of all three types of sensors and/or transport of nanoreagents for physical and chemical modification.

Current projects

Below is a tiny snapshot from a very dynamic and continually evolving state-of-the-art research portfolio that illustrates the breadth of research being undertaken and the creativity resulting when world-class multidisciplinary research teams attack challenging technical problems outside their normal field of study.

The graph on the right shows the defection of the AFM tip due to the force exerted on the nanoparticle as it approaches a rock sample in two locations as marked on the image of the rock on the left, Mineral #1 and Mineral #2.

James Tour’s team at Rice University, including Michael Wong and Mason Tomson, is designing nanoreporters — nanomaterial sensors based on carbon (hydrophilic carbon clusters — HCCs) and silica nanomaterials; this project illustrates the second type of sensor (nanomaterials, which are retrieved and interrogated). Nanoreporters are nanoparticles that can sense and record the local environmental conditions to which they are subjected. These nanoreporters may have the ability to sequester chemical, radioactive, or isotag tracers and change the concentration of these sequestered tracers on the basis of the time, temperature, and fluid (aqueous or hydrocarbon) parameters to which they are exposed, thereby providing a profile of the inter-well reservoir environment.

Boston University’s Bennett Goldberg and UT-Austin’s Rod Ruoff are collaborating to develop nanomaterial pressure-threshold sensors that are based on graphene membranes. Graphene is a single-layer carbon materal that is impermeable to gas-phase leakage. Graphene films can be tuned to deform at different pressure-threshold levels and are stable optically, electrically, and mechanically in caustic environments.

Yogesh Gianchandani’s team at the University of Michigan is using another approach to accurately measure oil and gas reservoir pressures. Their microelectro-mechanical system design measures changes in the spatial current distribution of pulsed DC microdischarges in a sealed microcavity that can be correlated to pressure. The system is sealed to permit operation in harsh multiphase reservoir environments.

In addition to the targeted nanosensor research, there are a number of projects seeking to better explain the fundamental behavior of fluids, nanoparticles, and their interactions as they are transported through complex semipermeable reservoir environments. Kenneth Crozier at Harvard University’s School of Engineering and Applied Sciences is trapping micro- and nanoparticles with a commercially available optical-tweezer system and then scanning the particles across open and closed micro-sized pores generated by optical and e-beam lithography on micro-fluidic chips. The 2-D chips are created to mimic pore throats and dead-end pores in rock.

Karsten Thompson at Louisiana State University’s Department of Chemical Engineering is the lead investigator, collaborating with Clint Willson and Dimitris Nikitopoulos, on a project using micro-particle image velocimetry based on total internal reflection fluorescence microscopy to measure and model the flow of fluorescent nanoparticles through micromachined “2.5-D” microfluidic chips. The chips being generated can have pore widths of 25 nm to 1 mm on several vertical layers. CT and X-ray microtomography scans of real rock are being used to try to generate vertically and horizontally adjacent “pores” that mimic reservoir micro-channels. Initially, artificial 2.5-D micro-fluidic chips based on a design courtesy of D. Crandall of NETL are used to simulate porous media in the laboratory. A combination of micromilling and hot embossing technologies are used to fabricate these test beds.

Another AEC research project, being conducted by Farzam Javadpour at the University of Texas, Bureau of Economic Geology, in cooperation with the University of Calgary (School of Medicine and School of Engineering)?and the Alberta Research Council, is using atomic force microscopy, in addition to some microfluidic chip and core-flood experiments, to measure the force realized by a nanoparticle as the particle is moved toward?interfaces?typically found in the reservoir (oil-water, water-mineral, oil-gas). The forces are then used as input along with other parameters into?2-D and 3-D transport models to predict the movement and retention of nano-particles in the reservoir.

AEC’s broad interdisciplinary research portfolio, composed of world-class researchers —many of whom are applying their creativity and intellect to the oil industry’s E&P problems for the first time — will redefine the scope and scale of data that is recoverable from subsurface reservoirs, revolutionizing modeling and simulation by providing high-resolution, real-time data streams from the interwell space. AEC’s research holds the promise of locating, imaging, and explaining why oil is trapped at the nanoscale, greatly improving efficiencies and reducing the 50 to 70% of today’s discovered resources that remain in place, and extending the useful life of hydrocarbons to support the world’s energy needs. AEC nanosensor research will have a broad impact on sensor needs in similar fields such as geothermal power, nuclear waste storage, and water resource management and in disparate fields such as medicine, pharmaceuticals, and clean energy. There is a huge potential impact that could be realized from “getting small.”

In summary, the AEC’s novel research approach is geared up and thus far is producing novel and exciting, though very preliminary, results. In the coming year, with 13 newly added projects (34 total), the consortium will begin to define the nanotechnology landscape and, collaboratively with its members, look into the future at the supporting technologies needed to develop sensor prototypes of varying size, distance, and data-collection capabilities for specific reservoir applications.

For more information, visit www.beg.utexas.edu/aec.