Dr. Georgios Papavassiliou Dr. Georgios Papavassiliou is Director of Research and Head of the Solid State NMR Laboratory of the Institute of Nanoscience and Nanotechnology at NCSR Demokritos. He is the former director of the Institute of Materials Science (2004-2012) and of the Institute of Advanced Materials Physicochemical Processes Nanotechnology and Microsystems (2012-2013). His research activities are focused in:
(i) The development and implementation of advanced Solid State NMR methods for the study of condensed matter systems. Part of the effort is devoted in the development of NMR methods for oil reservoir characterization.
(ii) Synthesis and characterization of novel nanomaterials in the areas of: (i) Transition metal oxides with complex electronic properties, (ii) Nanofabricated materials for catalysis and oil field applications (such as magnetic nanoparticles for oil-reservoir characterization, self healing oil-well cements, nanoparticles for enhanced oil recovery, etc.).
Nuclear magnetic resonance (NMR) is one of the most powerfool well-logging tools, applied by the petrophysical community to evaluate oil reservoirs: a single-sided permanent magnet and radio frequency (rf) resonator are lowered into a well in order to examine the fluid properties in the formation near the bore. Experiments conducted on such devices are mainly measurements of transverse relaxation time (T2) and self-diffusion coefficient (D), and are limited at a distance of only a few centimeters from the device. In most cases the obtained data are sufficient to distinguish fluid-phases and as the logging tool is drawn up the well, they provide a vertical spatial profile of fluid saturation and porosity [1, 2].
At laboratory-scale, NMR is a very powerful technique that provides critical information on the petrophysical properties of fluid saturated Rock Cores. Specifically, by applying 1H NMR experiments it is possible to acquire information on porosity, pore-size distribution, bound and free fluid, permeability, capillary pressure, and wettability [3]. Besides, by applying Magnetic Resonance Imaging (MRI) methods it is possible to attain structural and fluid flow properties in spatially resolved two dimensionl (2D) and three dimensionl (3D) maps [4]. Understanding multiphase fluid motion in oil recovery processes at laboratory-scale is critical for generating accurate models to predict field scale performance in the reservoir.
Here we present advanced NMR and MRI methodologies in the study of oil-gas-water-rock interactions in Carbonate Rock Cores. Focus will be given on 2D-NMR techniques [5, 6, 7] and the implementation of advanced inversion algorithms we have recently developed, for acquiring important NMR information on multiphase flow and Enhanced Oil Recovery.
References
[1] “Advances in NMR logging”, Freedman R., J. Pet. Tech., 2006, 60-66.
[2] “Fluid Characterization using Nuclear Magnetic Resonance Logging”, Freedman R., and Heaton N., Petrophysics 45, 2004, 241-250.
[3] “Core Analysis by Low Field NMR”, Straley C., Rossini D., Vinegar H., Tutunjian P., and Morris C., Core Analysis by Low Field NMR, Society of Core Analysts paper SCA-9404, 1994, 43-56.
[4] “Using MRI to study in situ oil recovery during CO2 injection in carbonates”, Brautaset A., Ersland G., Graue A., Stevens J., and Howard J., International Symposium of the Society of Core Analysts, 29 October – 2 November 2008, Abu Dhabi, UAE
[5] “Measuring adsorption, diffusion and flow in chemical engineering: applications of magnetic resonance to porous media”, Gladden L. F., Mitchell J., New Journal of Physics 13, 2011, 035001.
[6] “Fluid identification method based on 2D diffusion-relaxation nuclear magnetic resonance (NMR)” Hu F., Zhou C., Li C., Xu H., Zhou F., Si Z., Petroleum Exploration and Development 39, 2012, 591-596.
[7] “T1-T2 Correlation Spectra Obtained Using a Fast Two Dimensional Laplace Inversion”, Hurlimann M. D., Flaum M., Frulla P., and Straley C., Song Y.-Q., Venkataramanan L., J. of Magnetic Resonance 154, 2002, 261-268