Tag: Seismicity Monitoring

Modeling and Simulation Forum #9 Recording

Utah FORGE Modeling & Simulation Forum #9

"Microseismic monitoring and risk mitigation plan for the first Utah FORGE stimulations at the toe of 16A-32"

Presented by: Ben Dyer, Falko Bethmann (Geo-Energie Suisse)

August 18, 2021 at 11 am MDT

The injection well 16A-32, drilled at the Utah FORGE site towards the end of 2020 has a lateral section of ~4000ft that dips at around 30° and terminates at 8500ft at a temperature of ~240°C. Planned for later this year, a small number of stimulation tests at the toe of 16A-32 and will be monitored in real time by a deep microseismic network and large surface array. This forum will present the design of the deep monitoring network, the anticipated network performance and mitigation of seismic risks.

The deep network will consist of three established high temperature geophone strings and realtime processing software to derive event hypocentres and magnitude estimates. This primary network will be supplemented by behind casing and wireline DAS in the same monitoring hole together with a three level, 3 component fibre optic sensor string to evaluate the relative seismic performance of these less established systems. The aim is to process all of the data from the deep 3C geophone and fibre optic 3C sensor strings together with a subset of the DAS data in real time in order to monitor the data quality and synchronisation of these separate sensor systems, which will be a challenge due to large data volumes, different file formats and remote acquisition locations. For mitigation of seismic risk, processed data will be fed into a 'classical' traffic light system and an advanced traffic light scheme that incorporates lessons that have been learned from geothermal stimulations in Basel, Pohang and most recently from the Bedretto underground lab.

This is the 9th forum of the series and is intended to have an open format to present modeling and simulation, both completed and planned, as well as activities being conducted by the Utah FORGE Team.

This webinar has been recorded and is now available for viewing.

To follow along with the slides, the pdf of the presentation is available for download HERE

For previous forums and for the upcoming schedule check out the Modeling and Simulation FORUM page

Partner Spotlight – UUSS

University of Utah Seismograph Stations - UUSS

Reducing the risk from earthquakes in Utah through research, education, and public service.

The University of Utah Seismograph Stations (UUSS) maintains and operates a combined urban and regional seismic network throughout the State of Utah and a regional seismic network in Yellowstone National Park. UUSS monitors seismicity in these regions by providing earthquake locations and magnitudes. The monitoring in Utah is part of a state-federal partnership with the U. S. Geological Survey Advanced National Seismic System. Monitoring in Yellowstone is done as part of the U. S. Geological Survey Yellowstone Volcano Observatory.

In addition to regional monitoring, UUSS is building, maintaining, and operating a seismic network local to Utah FORGE. The primary goal of this network is seismic hazard monitoring. The complete network will consist of six stations located on the surface in carefully designed vaults, six stations in shallow boreholes, one deeper borehole, and three accelerometers located close to structures. Data from these instruments are sent back to UUSS in real-time. Once all stations are installed, over 2 GB of data will be collected and processed each day.

This data feeds into an automatic processing system that detects and locates earthquakes. For larger earthquakes, maps of ground shaking are generated, and alarms are sent for rapid review to seismologists who are on call 24 hours a day. All earthquakes are reviewed by seismic analysts and posted to the web.

To complement the local network, UUSS has deployed dense arrays of temporary geophones at times of stimulation to help better constrain the background seismicity and seismic velocity structure. The data from these deployments contributes to special studies. In one study, UUSS mapped the shallow shear-wave velocity structure of Utah FORGE and the surrounding area, and in another study, new algorithms were developed for detecting very small magnitude events from the stimulation process.

 

Find out more about other Utah FORGE team and partners HERE