High-resolution microseismic monitoring for water injection in Okuaizu Geothermal Field, Japan
K. Okamoto, Li Yi, Hiroshi Asanuma, T. Okabe, Y. Abe and M. Tsuzuki
Event name: The 22nd International Symposium on Recent Advances in Exploration Geophysics (RAEG 2018)
Publication date: 24 May 2018
Info: Extended abstract, PDF ( 676.74Kb )
A continuous water injection test was conducted to halt the reduction of steam production in the Okuaizu Geothermal Field, Japan. Understanding the spatiotemporal behavior of water flow within the reservoir associated with the water injection is essential to ensuring effective steam production. We conducted a high-resolution hypocenter determination using the double-difference method. In this method, relative hypocenter locations are corrected by using time difference in P-wave onsets of seismic event pairs. We found three characteristic seismic clusters associated with the water injection using this method. The creation of microseismic clusters seems to have a qualitative relationship with the distribution of well head pressures in this field, suggesting that microseismic monitoring could be a method for understanding fluid behavior in the reservoir.