By Peter Malin, SMU Adjunct Faculty
Peter Malin, an Adjunct Faculty in the SMU Huffington Department of Earth Sciences provided this update on the st1 Deep Heat project in Espoo, Finland. Peter’s company Advanced Seismic Instrumentation & Research (ASIR) is providing seismic monitoring for the project.
The drilling phase of the st1 Deep Heat project has ended with OTN-III drilled to a measured depth of 6.4 km by the end of April, 2018. Following drilling, this well was logged, with wireline methods unable to get to TD, so a drill pipe system was brought on site. Logging was complete today, 17 May, and placement of packers for the stimulation phase is to be determined by tomorrow. Stimulation will be approached in a slow and carefully monitored fashion, beginning with low pressure and flow on the 1st stage of the 5 stage packer and sleeve system.
A monitoring network has been established to detect any micro-seismic activity associated with stimulation. The monitoring network consists of 13 vibration monitoring stations called the Surface Network, all located in critical ground level facilities, and 12 borehole seismograph stations called the Satellite Network, located in 350 to 1200 m boreholes. In addition, a ten-level vertical array of 3-C seismometers has been installed in the OTN-II borehole, between 2.2 and 2.7 km depth.
These monitoring stations are linked to a Traffic Light System (TLS) where protocols are in place to continuously monitor and respond to any seismic events. Thresholds and responses have been established and are in place.
Baseline monitoring prior to stimulation began in January 2018 (6 months of required reporting before licensing), with staged TLS Amber and Red alert exercises in April. Monitoring will continue throughout stimulation, and beyond the end of the stimulation period.
Stimulation is scheduled to begin at the end of May 2018. Stay tuned – you will be among the first to know how it all goes!