SP2 Model MM2 for deep mine monitoring, without the need for bore holes.

The range from each sensor is up to 1km horizontally and in depth. This offers a significant saving to installation costs.

The unique ability of SP2 to predict and, therefore, to provide advanced warning of an imminent or longer term collapse due to mine or tunnelling activities is a revolutionary step towards providing greater mine safety, and maximising output from a mine. In addition, SP2 detects the potential impact and threat of liquids, including moving water and shifting oil deposits.  Voids may be detected by careful analysis of travel paths and event arrival timing.

SP2 uses sensors located on the surface above the mine, a 3D cubic model of microseismic events gives instant visual warning of a potential collapse in real time. Each event is located on the plan of the mine with a 360 degree rotating view.

SP2 gives potential for greater mine productivity by, for example, reducing the need for large pillars within a “room and pillar” mine tunnel.

With the unique ability to filter out extraneous sounds and ‘see through’ the noise of the working mine it is able to detect and locate events within a fully working mine.

Onscreen 3-dimensional rotating cube displays events as they develop, in real time.

This image can also be accessed and viewed via any web browser over an IP connection.

The events trigger a user selectable alarm, to give unattended automatic advanced warning of significant event clustering, potentially leading to a failure.

For ease of use, the 3D image clearly identifies location, direction and severity of microseismic events by coloured discs which are aligned with the seismic events and increase in colour depth with event magnitude.

The image in the middle is an actual extract of data recorded in a working long wall coal mine, where 18 weeks advance warning was able to be given. The subsequent failure happened as predicted and is documented in the case study below by the University of Liverpool, Department of Earth Sciences under the direction of Professor Peter Styles.

(18 weeks warning given to a working long wall coal mine in Leicestershire, UK.)

SureWave’s technology SP2, marketed at the time by the inventor Philip Shaw as an SP1 system, was installed on the surface and subsequently detected microseismic events at 23 weeks prior to the incident. This mine was already being monitored using conventional microseismic technology which failed to detect any events right up to the collapse. At 18 weeks before the event, exact timing and magnitude was able to be given by the SP1 technology.

On the day forecast, the mine was cleared of personnel as a precaution and it failed as predicted.  This seam was subsequently lost.

The significance of the detected events and subsequent failure and the impact this would have on the mine owners, justified independent monitoring and analysis by the Department of Earth Sciences, University of Liverpool, UK.

A full independent report was produced and is available detailing the monitoring and the techniques used to accurately predict the eventual roof collapse.