When Oklahoma’s L & M Construction hits a rocky formation, it relies on the impressive directional drilling capabilities of the Ditch Witch 4020
Hitting an unexpected rock formation while boring a path for gas or oil pipelines used to be a real drag for drilling crews at L & M Construction in Chandler, Okla. Typically, that meant backing out the bit, then switching out the directional drilling machine for a downhole mud motor to drill through the rock – a time-consuming and labor-intensive undertaking.
That all changed in 2007, when the company purchased a Ditch Witch 4020 All Terrain directional drilling machine, says Mike Melson Jr., the company’s vice president.
“Now if we hit rock, we just back out the drill and change out the bit in a matter of minutes,” says Melson. “And we don’t need a reclaimer on site to clean the mud produced by the downhole mud motor. Even a small reclaimer costs about $50,000, plus you have to dedicate one person to running it.
“With the Ditch Witch, hydraulics turn the drill bit, so you don’t need all those extra pallets of mud and the expense of setting up a reclaimer,” he continues. “If you drill, for example, about 50,000 feet a year in rock, I’d venture to say that from our experience, the Ditch Witch would cut your expenses by 30 to 40 percent.”
Melson cites another advantage: His crews are usually ready to drill in about 30 minutes because the Ditch Witch requires minimal setup time. That compares to about a half day to set up a mud motor and a reclaimer, just in case crews hit rock, then another half day to break down the same equipment. The Ditch Witch also eliminates the need for pre-drilling excavation.
“Furthermore, the reclaimer can’t completely clean the mud, so you end up pumping contaminated mud through the mud motor pump, which makes it wear out faster,” Melson explains. “It’s like running sand through a car engine without an air filter. Sometimes we’d have to replace the pump components every 200 hours. With the 4020, we don’t have the wear and tear from contaminants.”
Melson estimates that the 4020 enables L & M, which primarily performs directional drilling for pipelines in gas and oil fields in Oklahoma, to do from 30 to 40 percent more drilling per year. Part of that efficiency stems from the machine’s power: 25,000 pounds of thrust force, 40,000 pounds of pullback thrust and 5,000 pounds of rotational torque at 250 rpm.
“That kind of power allows us to bypass stair-stepping and perform two-pass drilling, which usually involves a six- or seven-inch-diameter pilot hole followed by, say, a 24-inch-diameter expanded hole for an 18-inch-diameter pipe,” he says. “Two-pass drilling is better because stair-stepping increases the chances of drilling a hole that’s not straight, because there’s nothing to center the pipe on … which allows the pipe expander to take the easiest path, which usually isn’t the straightest path.
“As a result, we try to drill the expansion hole in one pass, even though at times it can take us up to an hour to drill just 10 feet.”
As an example of the unit’s power, Melson cites a job two years ago where L & M crews shot two 880-foot-long bores through hard rock (8 hardness). It took 42 hours to drill the 6-1/2-inch-diameter pilot hole, then 92 more hours to complete the expanded 24-inch holes. The Ditch Witch made all the difference, Melson says.
DOESN’T MISS A BEAT
“I can honestly say we’ve never not completed a bore – left pipe in a hole or twisted off our tools – and that’s all because of the Ditch Witch,” he notes. “Sometimes we work near other contractors and you almost feel sorry for them because it takes hours and hours longer for them to finish. We recently worked 30 feet away from another contractor’s crew, and finished two days ahead of them on a 500-foot-long drill, working the same amount of hours.”
L & M crews love the unit’s cruise control function, which allows hands-free operation after the pipe is in motion, reducing operator fatigue. Automatic pipe loading, which conveniently positions the next section of pipe so the operator can easily attach it, is another crew-pleaser.
The $300,000 machine has already paid for itself, Melson says, and it helps attract business because companies know it can handle tough rock drilling.
“And if we get a call on short notice and don’t get an opportunity to first look over the bore, we can still rest easy because we know we can drill through either dirt or rock … we don’t have to hedge our bet by bringing along a reclaimer and a mud motor,” he points out. “We can carry everything we need on one 49-foot semi-trailer.
“The 4020 really is the life of our company,” he concludes. “It’s a big expense up front, but if you stick with it and get through the learning curve, it’s well worth it because it’s so efficient.”