Exploration drilling on the Sintoukola potash project wasn’t without its challenges for Meridian Drilling. Elemental Minerals’ ongoing project, in the Kouilou Province in the south west corner of the Republic of Congo is a high grade potash deposit of global significance.

However, the nature of deposits at the site meant that it was not a straightforward drilling operation.

In addition to the technical difficulties of core drilling in soluble potash salts, significant challenges had to be overcome when drilling the loose sand, clay and dolomitic limestone forming the overburden. It was Meridian’s experience with potash that led Elemental to first call on their assistance in May 2011.

With their experience and expertise, Meridian’s drillers were able to meet the challenge, operating three rigs on the project. These include two top drive rotary rigs – one Superock S5000 rotary, and one Gemsa MP1200H multi-purpose rig – for large diameter mud drilling in the top hole section and running / cementing casing; and a diamond core rig (Coretech YDXL) for coring the evaporite sequence.

Andrew Pedley of Elemental Minerals explained the challenge: “No two projects are the same from a driller’s perspective. Meridian was keen to learn and adapt to the challenges of drilling at Kola.” “It’s not easy drilling, a very poorly consolidated sequence to 200 m then salt to the end of hole at 350 – 450 m, which of course needs a special set of skills to maintain excellent recovery. Meridian managed to get it right.”

The Sintoukola Project comprises an exclusive exploration permit, for potash and associated salts, which covers an area of 1,436.5 km2 along the northern part of the coastline in the west of the country.

Meridian operates a fleet of nine rigs maintained to the highest standards and has built a reputation for being able to work in harsh and remote environments, with extensive experience in potash, precious and base minerals and water well drilling.

For the Sintoukola Project Meridian Drilling also invested heavily in large mud pumps to allow top holes to be drilled through overlying sands and laterites. Meridian have been drilling using annular blow out preventers to guard against the possibility of shallow gas being encountered, using full tri-salt mud system to prevent dissolution of potash salts.

Andrew explained why Meridian stood out from other drilling companies when Elemental were looking to further the project and how the two companies have been able to work together so successfully: “Meridian has always been able to remain flexible, to find the best solution for the Company, both technically and in management.

Open and honest communication between Meridian and EML has benefited the project.” “Meridian have been able to keep rigs turning with very little time down due to breakages or spare; a reflection of the skills and professionalism of the team.”

The importance of the project for Elemental meant that they needed a drilling company that were reliable and would adapt to their specific needs. They found this with Meridian.

With Meridian currently working on Phase 2 of the project, Andrew added, that Elemental would certainly call on their services again in the future. “I appreciate their open and flexible approach, obviously backed up with the technical ability and resources,” he said.