Fluid flow tomography of reinjection well by the vertical electric profiling method in Kazuno area, Akita prefecture, Japan

The Vertical Electric Profiling (VEP) methods were carried out for the exploration of fractures for the reinjection purposes in Kazuno area. The first field survey was conducted in 1985 by using a casing pipe of K-1 well and the drill site of K-5 was determined from the interpreted results. The K-5 reinjection well have met a good lost circulation zone of 135 t/h at the depth of 684 m. The second VEP survey was conducted in 1990 by using a casing pipe of K-5 well before and during the injection operations of the separated hotwater. The injected fluid was continuously monitored with 30 stations surrounding the well by the digital recording system controlled by a personal computer on the site. The distribution of fractures estimated from the detected flow paths show good agreements with the geometry of the major fractures obtained by the borehole imaging data by Schlumberger Wireline Service Inc.,.