University of Southern California USC Center for Geothermal Studies The USC Andrew and Erna Viterbi School of Engineering USC

Advanced Seismic Imaging for Geothermal Development

Dr. John N. Louie ( 2:00 -3:00p.m. HED-303)

October 06, 2011 —

In the geothermal fields of the Great Basin physiographic province of  western North America, drilling success or failure often  depends on hitting fault or fracture zones. Advanced seismic reflection imaging has proven to be the only effective geophysical means of accurately targeting geothermal drilling. At target depths of 1 to 2 kilometers, the pay zones are often less than 0.1 km
wide. Surface geological and “integral” (e.g., potential-field, electrical, magnetotelluric, seismic-refraction) geophysical studies have often proven successful at locating new geothermal fields for development. However, surface and integral methods cannot direct exploration or development within a field, and geothermal exploration drilling in the region has had a success rate as small as 10%. Such high risk for costly drilling has long  held back the development of the region’s full geothermal-power potential. The development of advanced seismic imaging techniques by Optim, especially the SeisOpt® technologies, has led to drilling success rates of 80% at some prospects. Advanced seismic imaging, as a “differential” method, is able to focus direct images of steeply
dipping faults as seismic reflectors, allowing  accurate planning of geothermal drill targets. SeisOpt® technology achieves the focusing and accurate location of structure and stratigraphy through thick piles of heterogeneous Tertiary volcanics, below complex surficial basin structure. This capability has allowed researchers at the University of Nevada, Reno, to use these seismic
images to carry out advanced seismic attribute analyses, model testing, and verification of tectonic hypotheses.  Optim and UNR are collaborating on research to further refine these imaging methodologies.

He is a member of the Society of Exploration Geophysicists, the American Association of Petroleum Geologists, the American Geophysical Union, the Geological Society of America, and the Seismological Society of America. Louie has published over fifty peer-reviewed articles in scholarly journals with his students and colleagues, for which over 500 citations have been
published. At the University of Nevada, Louie invented the refraction microtremor technology, which is a commercial success in building-code compliance. The technology was licensed in 2004 by Optim, a company started in 1997 by Louie’s graduates Honjas and Pullammanappallil that specializes in advanced seismic analyses for the energy and geotechnical industries.