New non-magnetic survey instrument

“Having had 20 years experience in the directional surveying industry, I consider the DeviFlex to be the easiest to use, most rugged non magnetic survey instrument on the market, designed by drillers for drillers”, said Mike Ayris, managing director of Downhole Surveys.
“There is no time limitation between survey stations, no Gyros, fast download via a cable, rugged waterproof PDA and data transfer to USB stick.”
The DeviFlex is run In and Out of the drill string, either on wire line or conventional, in the same way a core barrel is run, stopping briefly (five seconds) to take a reading at a three-metre or four-metre interval. A typical 250-metre conventional In and Out run survey takes less than one and a half hours to complete - a saving of one hour compared to MEMS Gyros per survey or approximately $250.00 per rig hour.
In addition, the DeviFlex download time takes only two minutes with results available at the rig and copied to a USB stick that can then be handed to the site geologist or supervisor.
The DeviFlex tool consists of two independent “non gyro”, measuring systems; three accelerometers and four strain gauges that are used to calculate inclination and change in azimuth per three- or four-meter station. In addition, the DeviFlex records and stores the gravity vector used for quality control, temperature, to its onboard memory.
Another fantastic feature of the DeviFlex is its incredible battery life, capable of 100 hours survey time before recharging.
A collar reference direction is required and can be entered before or after the survey. The DeviFlex is synchronised with a PDA through a cable. Once initialised the two x two-metre long sections are screwed together and placed inside the drill rods and fed either conventionally or pumped to the end of hole. If fed conventionally, an In run survey and an Out run is conducted, rotating the rod string approximately 90 degrees every station. A pump down survey records an Out run, measuring depth either on a Downhole Depth Encoder (DDE) or by pulling rods and surveying at three-metre intervals.
The results can be viewed on the PDA screen in the field once the data is downloaded from the tool, usually in less than one minute. The data is transferred to a USB stick and handed to geological staff for uploading directly to mine planning or other software.
Downhole Surveys are currently developing a highly accurate GPS-based true north finding device that will allow the drillers to input the starting reference azimuth relative to true north at better than 0.5 degrees.
This inexpensive device will also allow the driller to align their drill rig to a predetermined starting azimuth, eliminating the need for land surveyors to mark out tape lines on which the drill rig must try to align to.

For more information visit: www.downhole.com.au