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Friday, August 28, 2015

USA: Wyoming: How Seismic Imaging Improves Geothermal Drilling Success

Lecture: Advanced seismic imaging of geothermal reservoirs- is there a geothermal seismic signature?

Dr. John N. Louie, Nevada Seismological Laboratory, University of Nevada, Reno

12-1pm, Friday, September 4, University of Wyoming’s School of Energy Resources, Energy Innovation Center, Laramie, WY 82071

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 2km, the pay zones are often less than 0.1 km wide.

The development of advanced seismic imaging techniques has led to drilling success rates of 80% at some prospects. Advanced imaging is able to focus direct images of steeply dipping faults as seismic reflectors, allowing accurate planning of geothermal drill targets. The 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 is allowing researchers to use these seismic images to carry out advanced seismic attribute analyses, model testing, and verification of tectonic hypotheses. We are further refining the imaging methodologies, conducting joint inversions of seismic along with other geophysical measurements, and inspecting the amplitude-versus-offset (AVO) characteristics of geothermal reservoirs in Nevada.