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Where There’s A Will, There’s A Way: Treacherous Terrain Tests The Skills Of An Arkansas Contractor
“Normally you pump in one spot, drill through it and just complete the job,” Cline says. “We pumped in four places on this project. We would drill for a ways, hit a void, start losing fluids, pump cement in and let it set, then go back and drill through the cement. We repeated this process four times. It really affected our production rates. It had nothing to do with the capabilities of the drill; it was all about the conditions, which is what I was concerned about before I agreed to take on the job.”
Challenge No. 3 — rock reaming
Having been involved in HDD since the trenchless installation method was first introduced, and his trade territory is situated near some of the hardest, most complicated rock in the country, Cline has learned a thing or two about tooling; specifically, reamers. Early on, he had some frustrations with what he considered to be inefficient reamer tooling -- especially for boring through rock. “Upsizing capacity for reamers then was limited to two to 3 inches per ream, often requiring multiple passes for a single bore. Most reamers were also hard on equipment with a tendency to steer off course,” he says.
So Cline got proactive.
“I wanted a reamer that would take out no less than five inches of material on a single pass and be easier on equipment,” Cline says. “We worked on a design change by increasing the size of the rollers situated on the front and back of the hole opener. Consequently, on this job, instead of having to ream multiple times, we reamed one time with the new larger roller design. It’s a design approach that we’ve found to be highly successful and more efficient.”
Rarely does any contractor face such diverse and demanding -- not to mention unpredictable -- circumstances as underscored by the fact that it took Cline more than three months to successfully complete the 1,170-foot bore, a length that under “normal” circumstances, would likely have taken less than 30 days.
Halfway through the bore, the body of the mud motor Cline was using wore out forcing him to pull back and replace it in mid-bore. It took five drill bits to complete the bore and five 18-inch reamers. Despite having lost location of the drill head on three separate occasions, Cline’s crew emerged on the exit side within 30 inches of their target -- a testament to the skill, experience and diligence of his drill operators and supporting cast of underground experts.