| Abstract |
In the Hatchobaru geothermal field, the reservoirs are controlled by two main fracture systems: one trending W-SE, and the other NE-SW. The fractures trending M-SE is, from north to south, the Komatsuike Fault, the Komatsuike Subfault and the Hatchobaru Fault, and they function as conduits through which the geothermal fluid flows. This paper shows that it is becoming clearer that the fracture trending NE-SW is as permeable as the W-SE trending ones for the deep-seated hot water, based on considerations about the geothermal structure derived from the following recent data. 1) Results of the aero-photo and satellite image analysis. 2) Gravity, Magnetotelluric and CS4MT survey results. 3) Well data such as loss of circulation zones, and PTS logging data. 4) A comprehensive analysis of the existing information and of the above data. |