Modeling of the Vertical Deformations During Exploitation of the Mutnovsky Geothermal Field, Kamchatka, Russia

Abstract

Vertical deformation ground leveling was conducted annually in Mutnovksy during 2004-2013 using a network of well markers. Three types of deformation areas with different transient vertical deformation regimes were identified on the basis of these measurements. The first type of deformation area is located in the central part of the Dachny site, where some positive (upward) vertical deformation (2 – 5 mm/year) was observed. The second type of deformation area is located in North reinjection site, where there was no significant vertical deformation observed during 2003-2006, wheareas some positive (upward) vertical deformations (6 – 7 mm/year) took place during 2006 – 2008 followed by negative (downward) vertical deformations (5 – 8 mm/year) during 2009-2010. Finally, the third type of vertical deformations is located on Verkhne-Mutnovsky site, where significant subsidence has been taking since 2008 at a rate of 6 – 18 mm/year. Coupled fluid flow and geomechanical simulations with the TOUGH-FLAC simulator were performed using a previously developed TOUGH2 model (Kiryukhin, 2013). THM modeling reasonably explains relative vertical movements during exploitation of the Mutnovsky geothermal field, if considering division of the field by Main Fault into two compartments with different properties for the foot wall block and hanging wall block of the Main Fault.