At First Bauxite’s massive refractory bauxite properties in Guyana, South America, the weather conditions and terrain – to say nothing of the snakes – make for unique challenges. Headquartered in Vancouver, British Columbia, First Bauxite is well on its way to its near-term goal of becoming a medium-sized producer and supplier of high-quality calcined bauxite. The company’s Bonasika and Waratilla-Cartwright properties are part of Guyana’s historical coastal bauxite belt that was first drilled in the 1940s by Alcan.
With two rainy seasons (May to mid-August and mid-November to mid-January), flash floods are a constant threat. The terrain is alternately hilly and swampy, at times making movement of drilling rigs and other vehicles dangerous. And, under the thin layer holding up the jungle carpet, the overburden of silica sand often is too porous for traditional mud-rotary drills.
It’s the main reason why First Bauxite purchased a Sonic Drill Corp. rig for its exploration and mining operations. Developed in British Columbia by company founder Ray Roussy, the sonic drill uses vibration combined with rotary motion to advance the drill stem, along with air or water as a lubricant, rather than the traditional drilling mud.
This combination causes less friction on the drill bit, meaning a smaller engine can be used, greenhouse gases can be reduced and fuel costs lowered. Even more important, the sonic can drill three times to five times faster and produce continuous core samples with virtually no contamination.
“You just run your casing and that’s your wall; you don’t have to spend days mixing mud, and you don’t have friction in your hole,” explains full-time drilling consultant Randy Pruden, who was hired to train Guyanese operators on the sonic drill. “In Guyana, the overburden is mostly silica sand. We just blow that out through a 5-inch pipe and then, afterwards, we get a 3-inch core to the bottom of the bauxite. With the casing in place, no sand can contaminate it. It’s so fast, we can just shoot it to the zone we’re looking for, and then do a continuous casing to the bauxite and that seals off that zone. We never have to worry about silica sand in the assays.”
Pruden, who travels the world concentrating on interesting and unique drilling jobs, says, “As far as I’m concerned, Ray Roussy has developed the best sonic drill head in the world right now. The improvements done on that head are phenomenal. He’s constantly putting his rigs into new fields for new applications and, when he finds out what the limitations are, he corrects them. On any new job, he likes to get feedback on the problems and solve them, whether it’s the equipment or drilling procedure,” says Pruden.
In the past 4 months, using the newest rig from the Sonic Drill Corp., a custom-built 550 series crawler, Pruden says that he has had very few problems, despite the less-than-ideal conditions. Operating 24 hours per day, his crew has put in 620 hours on the rig in February 2010, alone, with only 28 hours of downtime (mainly because his living quarters are about 2 hours from where the machine is working).
“With the terrain we work on in Guyana, the 550 series crawler is ideal,” says Pruden. “The bauxite seems to be located in the lower-lying areas. Guyana means ‘land of waters,’ so that should give some idea of what we’re facing.”
With the overburden being mostly silica sand, a rubber-tired drill rig would never get any traction, which is another aspect where the crawler has made a difference.
“The drill patterns run from the hills through the flats of the valleys so as to close off the range of the bauxite,” Pruden says. “We use a skid that we pull, with all our drill strings and tools. The drill skid is pretty much self-contained, and the weight is upwards of 4.5 tons. The 550 Series crawler pulls this skid up and down the hills with the silica sand and through the lower wet valleys with little or no assistance, which is a huge time-saving feature for us because we don’t have to wait for another machine to come and move the rig to the next drill site.”
Most of the bauxite in Guyana is close to the surface, making the exploration process fairly quick. Pruden says the deepest a test hole will go is 200 feet if no bauxite is found.
“If we get to 195 feet and then get 30 feet of bauxite, we’ll carry on,” he explains. “The average hole depth is 140 feet. We drill in patterns to find the limits of the deposit, and then drill the deposit, but all of the deposits so far have been high-grade ore.”
First Bauxite is developing a processing and loading facility near the current operations at Sandhill, on the Demerara River. The company is building a school for what is expected to be a growing mining settlement, and hires as many local people as possible.
“I have a great group of guys to work with,” says Pruden. “The guys on the drilling crew all have taken technical training as welders, in electrical or hydraulics – things like that. They’re all willing to learn new technical trades, and the sonic is quite technical.”
Still, it’s a project where, if the terrain or climate isn’t causing problems, the wildlife can. On one occasion, Pruden says he was called out to the drill rig at night to solve a problem: “I put my hand on the light to climb the rig, and it felt like there also was a stick there, so I hauled it out. It wasn’t a stick, it was a snake.”
In fact, it was a Parrot snake, a member of the viper family, although the area also is home to coral snakes and others species. “Any enclosure or any place on the machine where moving parts create heat, you have to be really careful since the snakes particularly like getting up in the engine.”
In a tale filled with snakes, swamps and silica, the sonic drill rig was the one aspect that didn’t prove challenging – successfully fulfilling its role with ease.
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