Geotech Drilling recently scored their first ‘hole-in-one’ at Anglo American’s Grasstree Mine site, when our 2,450m lateral well intersected our 408m deep vertical well on the first pass.
This was achieved using Integrated Directional Services’ (IDS) Rotating Magnet Ranging Service (RMRS), which uses the rotation of a magnetic bit sub located directly behind the drill bit to create a time-varying magnetic field that can be detected up to 70 meters away in a second well, in this case the vertical target well which had a receiver on a wire-line.
The RMRS kit consists of a rotating magnet sub that contains stacks of powerful rare earth magnets that create an A/C magnetic field when rotating with the bit. This magnetic field is monitored by a sensor probe and provides a distance and direction from the probe to the drill bit.
Accurate positional information can be acquired at around 70 metres of lateral separation, allowing for significant trajectory correction prior to intersection. Our successful Driller was Divay Kumar, who maintained great consistency of angle and speed throughout the lateral well, so much so that at the 70m mark (from intersection) we were only 1m off target.
The RMRS system then honed in on the vertical target and intersected on the first pass, thus eliminating to need to perform any ‘drive by's’. This ultimately led to a saving on metres drilled of approx. 80-120m. Steering for IDS was their Operations Manager, Steve Wilson. Steve has been in the directional drilling and surveying business for almost 14 years.