Bit selection is key to performance

The economic downturn has undoubtedly made its mark on the coal and potash industries. Despite the plummeting prices of most commodities, coal and potash remained viable throughout most of 2009, and in some sectors even increased by a small percentage, primarily due to long-term contracts that were initiated during the previous commodity boom. This led many drilling companies that specialized in other mineral commodities toward coal and potash exploration projects — flooding the market with new operations. With an increased number of players in the market and fewer investment dollars to go around, coal and potash drillers have become more cost-focused as they have been faced with unprecedented downward pressure on their margins.

Productivity has become more important than ever before.

While margins have improved for many drilling contractors in 2010, some experts are saying that full recovery will be slow. In addition to a new, more competitive market and lower contract margins, drilling contractors are still faced with many traditional challenges. Coal and potash can be found in highly varied ground conditions throughout the globe and even with a high degree of specialization, these varied conditions lead to difficulty for drill crews.

While challenges vary tremendously from region to region, it is common for surface exploration crews worldwide to encounter hard seams when drilling in soft ground. When this is the case, the bit being used to drill the borehole becomes even more critical to productivity.

“These hard lenses invariably tear up traditional surface set drill bits,” says Monika Portman, corporate communications manager for Boart Longyear. “The crew then has to trip out the rod string to replace the bit — this causes costly downtime, and can have a significant impact on the profitability of an operation.”

Surface set coring bits that are traditionally used in these applications often don’t hold up to the difficult drilling involved in these types of formations. They are typically composed of a hard matrix with a single layer of natural diamonds on the surface. This single layer of natural diamonds struggles to perform when faced with a hard seam or other abrupt change in ground conditions. Where drillers were getting 457.2 m on average, technology now exists that can reliably double or triple this productivity, saving downtime associated with ruining bits and tripping rods out of the hole.