SDI | Engineering and Geophysics
An impediment to progress in predicting the effects of natural fractures or controlling their behavior in engineering operations is the considerable uncertainty in measuring or accurately predicting their attributes. Sampling is problematic at best, and for key parameters—open fracture length and height for example—impossible. Outcrop analogs are vital for understanding fracture attributes but they may be misleading if not used with great care.
All this means that seismic and other indirect methods for fracture evaluation are also hard to validate and that interpreting engineering results is fraught with uncertainty.
Building better predictive models that take the relevant physical processes into account is essential, as is comparing model results with structural petrologic reconstructions of actual fracture growth histories from the subsurface and from good outcrop analogs at each step in model development. Laboratory experiments on fracture growth in chemically reactive environments are also needed to really understand what’s going on.
This is the central effort of the Structural Diagenesis Initiative.
Engineering tests and geophysical probes are useful for comparison with initiative results.
On the engineering side, investigating how fracture sizes, patterns, and diagensis affect fluid flow is an objective that is of interest. Tests of predictive models in subsurface zones where engineering/production experiments are being carried out are useful for validating seismic probes of fracture attributes and for verifying that models are accurately predicting key aspects of the fracture pattern.
The Initiative aims to foster these kinds of tests although they are not a central facet of the Initiative research agenda.
A key step in advancing seismic methods is rigorous validation accomplished by fracture characterization, modeling, and engineering tests carried out in the seismic volume.
Some engineering tests are conducted with researchers from the Department of Petroleum & Geosystems Engineering.
Our primary liaison for collaborative work on geophysics is with Sergey Fomel’s group at the Bureau of Economic Geology.
Fomel
Fomel is a Professor in the Jackson School of Geosciences, University of Texas at Austin, with a joint appointment between the Bureau of Economic Geology and the Department of Geological Sciences.
Sergey received a Ph.D. in Geophysics from Stanford University in 2001 and worked previously at the Russian Institute of Geophysics and the Lawrence Berkeley National Laboratory. He received the J. Clarence Karcher Award from the Society of Exploration Geophysicists (SEG) in 2001, Best SEG Poster Presentation Award in 2007, Conrad Schlumberger Award from the European Association of Geoscientists and Engineers (EAGE) in 2011.
Some results of the collaboration include:
- Fomel, S., Eichhubl, P., Klokov, A., Olson, J., Sheibani, F., Laubach, S.E., T. Weisenberger, T., Hooker, J. N., Fall, A., 2014, Multiazimuth Seismic Diffraction Imaging for Fracture Characterization in Low-Permeability Gas Formations, Report, 08122.53, Research Partnership to Secure Energy for America, 168 p. | Report
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Burnett, W. A., Klokov, A., Fomel, S., Bansal, R., Liu, E., & Jenkinson, T., 2014. Seismic diffraction interpretation at Piceance Creek. Interpretation, 3(1), SF1-SF14.
- Marrett, R., Laubach, S.E. Olson, J.E., 2007, Anisotropy and beyond: geologic perspectives on geophysical prospecting for natural fractures. The Leading Edge, 26/9, 1106-1111. | view | view at GSW Reprinted in Fractured reservoirs: A compendium of influential papers (2008), AAPG.
Structural Diagenesis Initiative Main Page
Engineering and Geomechanical Modeling Research at Petroleum & Geosystems Engineering