Planning and Results of Well Drilling Based on the Interpretation of Geological Structure in the Hatchbaru Geothermal Area

Abstract

For the Hatchobaru geothermal area, the planning of well drilling is done based upon a conceptual model of the geothermal area which is periodically updated using the latest geological information obtained from the latest drillings and from the results of updated reservoir simulations. Actual experiences of recent years show that the drilling plans made using this methodology have been effective.

Production well H-37 was designed to tap the NE4 fault at a depth of 2,750 m and the Komatsuike sub-fault at a depth of 7,800 m. According to the results of drilling, the presence of feed points was confirmed at 2,177 m and 1,790 m. The pmduction test of this well rendered an output equivalent to 6,140 kW. These results confirm the adequateness of the geothermal conceptual model constructed for the Hatchobaru geothermal area.