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Fracture mapping tool designed

Journal Article · · Geotherm. Hot Line; (United States)
OSTI ID:6874626

Researchers at Sandia National Laboratories have designed and successfully tested a high-power, high-resolution tool. The tool can help exploration engineers recover more energy from geothermal, oil, and gas reservoirs by locating deeply buried rock fractures. A prototype of the tool, built by Southwest Research Institute of San Antonio, Texas, has been successfully demonstrated at a special granite quarry test facility south of Albuquerque, New Mexico. During field tests, the tool has detected simulated fractures that were more than 30 feet away from a test borehole. No other mapping tool has this directional capability. The tool, which fits in a typical uncased borehole, emits pulses, each of which lasts just eight billionths of a second. The frequency spectrum of the pulses ranges up to the VHF band. Fracture direction is determined by transmitting powerful, highly directional radar pulses in a known direction from a borehole. Discontinuities in the rock will interrupt and reflect radar signals; therefore, signals that return to the tool's receiving antenna indicate the presence of fractures. The return signal's time delay translates into distances from the borehole. The transmitter and receiver rotate in place, permitting the tool to scan for fractures in all directions from the borehole.

OSTI ID:
6874626
Journal Information:
Geotherm. Hot Line; (United States), Journal Name: Geotherm. Hot Line; (United States) Vol. 17:1; ISSN GHLID
Country of Publication:
United States
Language:
English