Preliminary results and status report of the Hawaiian Scientific Observation Hole Program

Abstract

The Hawaii Natural Energy Institute (HNEI), an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa has drilled three Scientific Observation Holes (SOH) in the Kilauea East Rift Zone to assess the geothermal potential of the Big Island of Hawaii, and to stimulate private development of the resource. The first hole drilled, SOH-4, reached a depth of 2,000 meters and recorded a bottom hole temperature of 306°C. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole, SOH-1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1°C and effectively defined the northern limit of the Hawaii Geothermal Project-Abbott - Puna Geothermal Venture (HGP-A/PGV) reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5°C and has sufficient indicated permeability to be designated as a potential "discovery". The SOH program was also highly successful in developing slim hole drilling techniques and establishing subsurface geological conditions.