This Small Business Innovation Research (SBIR) Phase I project will develop a new tool for determining the microstructure of porous materials including oil and natural gas reservoir rock. This is a critical step in the recovery of oil and natural gas from many reservoirs around the world. Methods exist for the determination of rock porosity and the distribution of pore sizes, but the determination of permeability, although central to oil and gas recovery, has remained a difficult problem. Phase I will demonstrate the determination of rock microstructure using low-field nuclear magnetic resonance (NMR) spectroscopy of hyperpolarized noble-gases. Recent research indicates that certain isotopes of helium (3He) and xenon (129Xe) can be given a large non-equilibrium "hyperpolarization" using laser optical pumping. This gives them an NMR signal two to three orders of magnitude larger than is found in standard proton NMR. Furthermore, the laser-induced non-equilibrium polarization of 3He is independent of applied magnetic fields, thus allowing a reduced system cost, lower susceptibility effects, and better imaging of partially conductive media. Phase I will include NMR measurements with 3He and 129Xe within reservoir rock as well as models of porous media. A low-field imaging apparatus will be designed and built for experiments in Phase II. This technology is expected to have many applications in materials development and characterization as well as in oil and natural gas recovery.
