Geotechnical

ESG offers complete microseismic monitoring solutions for a variety of geotechnical applications including underground storage facilities (LPG sites and nuclear waste repositories), vibration thresholds and blasting and monitoring of structures such as dams, high speed rail tracks, bridges and tunnels.

Underground Storage

Our underground storage systems incorporate microseismic, temperature and pressure data into one fully integrated monitoring platform.  This complete system is customized to include everything from integrated acquisition through to visualization based on client needs.

Underground Gas Storage (LPG and LNG)

Microseismic monitoring systems have been installed at many underground LPG and LNG storage sites to ensure containment integrity. Typically ESG’s Portable Paladin™ and seismic accelerometers are installed from the water curtain galleries to provide high resolution seismic coverage of the caverns, providing operators with real time 3D event location display of any seismic activity occurring within the site.

Peizometers are also installed at various locations around the cavern to monitor the hydrostatic pressure around the water jacket, and correlate any associated fluid escape with seismicity that may be occurring within the cavern. Pressure data is automatically collected by the system, and presented graphically to the operators.

Nuclear Waste Repository Storage

ESG is actively involved in using microseismic monitoring to study the long-term integrity of the underground structures used to store nuclear waste.  ESG’s monitoring systems characterize the stress distribution around the storage caverns and can identify and characterize micro-fracture development and rock properties. Our systems can be employed in a laboratory environment or in-situ during underground tests. The data obtained from these monitoring programs are then used to calibrate geotechnical models and understand the rock mass response to excavation. Tests have also been completed to include data from heating or pressurizing the rock.

Rockfall and Rail Monitoring

In conjunction with our partner Alstom Signaling, ESG has developed an innovative solution for monitoring railway tracks and detecting dangerous hazards such as rock slides, collisions with elevated structures, derailments and other conditions.

The microseismic railway monitoring system can be set to ignore non-threatening smaller rock falls, while automatically notifying railway operators of major events that could pose significant risk.  For more information, please see this following resources:

Case Study: Microseismic railway monitoring system successfully detects rockfall events

Publication: Real time detection of rock fall events using a microseismic railway monitoring system

 

Dam Monitoring

ESG‘s microseismic monitoring systems can be deployed to monitor dam structures and water reservoirs.

During the initial filling of dam reservoirs, changes in pressures and loads can cause considerable stress redistributions within the surrounding rockmass. Seismic events that occur around the reservoir basin or at the dam/rock interface can be recorded, located and visualized on a 3D map of the area, providing a continuous evaluation of structural integrity.

Other dam monitoring applications include:

  • Abutment monitoring—Abutments are traditionally the weaker points of the dam structure. Microseismic systems can monitor these areas for abnormal seismicity, and ensure that the proper conditions are maintained to avoid weakening or collapse.
  • Design threshold monitoring—In the event of an earthquake or other large scale seismic event, a microseismic monitoring program can indicate if vibration levels (including PPA and PPV) have exceeded the design thresholds of the dam. Additional cracking that might indicate internal structural problems can be recorded and located by the system.
  • Optimize water reservoir levels—Seasonal water level uplift and decreases can have adverse effects on the elasticity of the rockmass in large reservoirs. Exceeding elastic limitations can result in micro-fractures within the rockmass, which could lead to disastrous occurrences. Dams can use detected seismicity to regulate their water levels and determine an optimal range of upper and lower limits.

Tailings Dam Monitoring

ESG’s tailings dam monitoring system provides users with information that is critical to tailings dam operations and helps to mitigate operating risk while improving safety for employees, the facility and the surrounding environment. 

Features of ESG’s tailings dam solution include continuous monitoring, data processing and reporting services and alarm options to notify operators of seismicity exceeding pre-determined thresholds.

ESG’s Tailings Dam monitoring solution evaluates seismicity at the dam site, and integrates other forms of geotechnical monitoring which may provide insight into the structural integrity of the dam and surrounding area, in one complete system.  Options may include:

  • Geophones
  • Accelerometers
  • Vibrating wire piezometers
  • Crack meters
  • Tilt sensors 
  • Inclinometer sensors

Vibration and Blast Monitoring

ESG has developed a complete system to simultaneously monitor multiple frequencies that have the potential to exceed human tolerance to vibration. 

ESG’s Vibration Monitoring Solutions and real-time monitoring of specific UHRS (Uniform Hazard Response Spectra) help operators ensure that vibrations do not exceed the design and engineering thresholds of foundations and structural members in question.

Geothermal

Microseismic monitoring adds value to geothermal projects by mapping the fracture volume in the rock formation following hydraulic fracture stimulation while providing feedback on generation of any larger magnitude induced seismicity. 

Real-time monitoring of event distributions enables operators to observe the behaviour of the formation during stimulation and identify properties of the reservoir which could affect geothermal operations.  Integration of near-surface instrumentation provides feedback on induced seismicity and may be used to implement traffic-light systems based on detection of larger magnitude events.  Microseismic mapping also identifies potential by-passed zones which were not sufficiently fractured during the simulation, enabling operators to adjust stimulation treatments to maximize fracture coverage.

ESG has a full range of temporary and permanent downhole and surface monitoring equipment available for microseismic monitoring of geothermal applications.  Our extensive experience in real-time hydraulic fracture monitoring means that clients can have ultimate confidence in the microseismic data and interpretation provided by our trained team of geophysicists and engineers.

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