Hydraulic Fracturing Experiment at Akinohiya. Akita. Japan (PART 2)

Abstract

It is indispensable for the Hot Dry Rock geothermal energy extraction system to create a man-made fracture system as a heat exchanger in hot rock. Hydraulic fracturing operations with using open-hole packers have been conducted so far to make the system. Ilowever. as the depth of the fracturing increased, the operations were often failed because of packer damaged at high temperature and high pressure (Franke et.al. 1984). We developed a new hydraulic fracturing method (named' casing reamer and sand plug method, ) without using open-hole packers to avoid the packer problems. Casing reamer is a tool which cuts a casing pipe set in a well. Sand plug is used to prevent the injected water leaking into pre-existing fractures. The method was applied to a well of 400m depth and demonstrated to be practical.