Book Description
During the acid treatment of a subeconomic well at the Beowawe Geothermal Field, numerous seismic events were detected of which 22 could be located. The events occurred following a first stage of the acid treatment and generally define a trend paralleling the surface trace of the Malpais fault. No seismic signals were detected following a second stage of the acid treatment, despite the injection of almost twice as much additional fluid. It is postulated that the cause of seismic events following the first stage was due to shear failure of chemically weakened cemented fracturs or joints in the reservoir. Presumably reservoir strain was sufficiently reduced to preclude further rock failure during the second day of treatment.
