UK and Dubai headquartered Meridian Drilling is looking forward to fresh challenges after concluding its four-year involvement with the Allana Potash project in Ethiopia. The project saw Meridian Drilling complete 25,000 m of drilling; operating two Atlas Copco CS14 wireline drilling rigs for 24 hours a day in the harsh and remote Danakil Depression. Starting in 2009, the contract was initially for just 3,000 m of diamond drilling, and Meridian’s Managing Director Jeremy Moore explained he was initially advised not to take it.

“When we first took the contract, everyone thought we were taking a considerable risk,” Moore said. “The problems were obvious – the heat, the remoteness of the location and huge logistical challenges – but I had a hunch, that the project could be extended, and the management and drilling experience that we could gain, would be invaluable.”

Those physical challenges included the fact there were no roads or infrastructure within miles of the proposed drill site, with daytime temperatures often exceeding 50°C. Meanwhile salt, whipped up by strong winds, kept Meridian’s maintenance team busy by causing regular damage to mechanical equipment.

Below ground there were also issues to overcome. “Drilling through differential beds of carnallite, bischofite and other halides led to dissolution if the drilling fluids were not correctly balanced.,” Moore explained.

Meridian Drilling used a full, tri-salt mud system to prevent the dissolution of the potash salts, while casing was driven deep into the ground and concrete drill pads were constructed to stabilize the soft alluvial soils at surface.   

Both PQ and HQ core samples were collected from the potash sequence for analysis with each hole being logged using industry standard down-hole geophysical logging techniques.

The results were positive, giving an estimated 60 million tonnes of recoverable ore within Alana Potash’s mining concession.

“We took a risk in coming to Ethiopia, but the risk paid off,” Moore said. “In the process Meridian has developed a reputation for its ability to deliver professional and reliable drilling services in remote locations.”