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.