Seismology

Using pre-existing or customised single mode or multimode fibre optic cables, Silixa offers continuous, real-time monitoring of seismic activity to map the Earth’s subsurface and fault zones with unprecedented detail.

This enables us to understand seismic hazards and the associated risks, which is a great step forward in protecting people and the environment.

Silixa’s iDAS, the intelligent Distributed Acoustic Sensor, converts an optical fibre to an array of seismic sensors, allowing to leverage pre-existing fibre networks, including submarine telecommunication cables, for dense seismic monitoring at a relatively low cost.

iDAS can be deployed to monitor natural or induced seismicity and be used to image the Earth in a wide range of applications and sectors.

Microseismic event recorded on a vertical borehole cable at the FORGE, Utah geothermal experiment.

  • Earthquake seismology
  • Volcanology
  • Glaciology
  • Hydraulic fracturing
  • Enhanced Geothermal Systems (EGS)
  • Mining
  • Carbon Capture and Storage (CCS)

The broadband sensitivity of the iDAS (1mHz to 50kHz) makes it suitable for large earthquake and microseismic event detection. The dense spatial and temporal sampling provided by instrument captures the full wavefield giving data ideal for imaging and full-waveform studies.

Data can be recorded on single-mode or multi-mode fibre using cables constructed to suit the environment or on so-called dark fibres, pre-existing telecommunications networks.

Fibre-optic cables are suitable for harsh environments and high/low temperature deployments. iDAS has been successfully used to monitor EGS projects, image fault zones, understand ice sheet movement and deformation, understand magma and gas movement in volcanoes and inform hydraulic fracturing operations.

Reliable monitoring to protect people and the environment

Understanding seismic hazards and the associated risks helps protect people and the environment. Dense spatial sampling over long distances enables detailed monitoring and imaging with large-aperture arrays.

Unlike traditional point sensors, Silixa’s iDAS permits seismic monitoring over a wide area with only one recording device (one interrogator). Existing fibre networks can be used, providing a high-density array with minimal deployment effort and maintenance.

Silixa’s monitoring solution captures the entire wavefield offering unprecedented data quality

The dense spatial and temporal sampling provided by the system captures the full wavefield giving data with unprecedented detail and ideal for imaging and full-waveform studies.

Flexibility in deployment possibilities enable the use of iDAS in harsh, high/low temperature and remote environments

Fibre-optic cables can be designed for high-temperature environments or harsh environments (e.g., geothermal settings). Cables can be deployed on the surface or in boreholes where they can be cemented behind casing, strapped to tubing or deployed by wireline. Installations can be permanent or temporary.

Fibres can be deployed along cased active wells, removing the need for a dedicated monitoring well. The same fibre-optic cable installation can be used for on-demand repeat measurements for many years.

Remote operation of data collection facilitates time-lapse surveys on-demand

iDAS data collection can be performed remotely once the interrogator is installed. This allows time-lapse monitoring or instant survey capability following an event of interest. The remote data collection enables seismic surveys with a low environmental footprint in environmentally sensitive areas.

Multiple measurements possible with one cable

Using the same fibre-optic cable seismic (DAS) measurements can be combined with strain (DSS) and temperature (DTS) measurements to facilitate integrated interpretation and provide greater insight into links between seismic events and fluid flow and ground deformation.

Significant cost-savings are ensured by leveraging pre-existing fibre networks

iDAS data can be recorded using pre-existing fibre networks, including submarine telecommunication cables, so-called dark fibres. iDAS works equally well on both SM and MM fibres. This provides dense seismic monitoring at a relatively low cost.

Extra wide broadband sensitivity enables the full range of seismic measurements.

Silixa’s iDAS has a broadband frequency response, from 0.001 Hz to 50 kHz, making the technology applicable to the full range of seismic measurements, from teleseismic earthquake to microseismic event detection.