Advantages of Dual Rotary

Switching to this drilling method is increasing due to its versatility, efficiency, and cost-effectiveness to drill a cased hole through unconsolidated formations.

By Mike Price

Many water well contractors are rethinking how they operate today with the volatile fuel costs and ongoing labor shortage.

Brant Beecroft of Beecroft-Danwell Co. LLC believes in the dual rotary drilling method and took delivery of his Derex 1340-12 DR rig in May 2022. Photo courtesy Beecroft-Danwell in Frederic, Wisconsin.

Some are turning to the dual rotary (DR) drilling method by either purchasing a new rig or converting their current rig to it. It’s an increasing trend that is expected to gain importance in the field.

“There’s not a lot to say about the rig that it isn’t already famous for. It is well designed and has helped us achieve excellent results in all formations, especially boulder areas,” says Cole Sullivan of Sullivan Water Wells in Chugiak, Alaska.

“We got our first DR in 2002. We bought it brand new and picked it up from the [Foremost Industries LP] factory. We have since purchased three others and one Nordic Drill for a total of five dual rotary style rigs. Two DR-12s, one DR-24, one DR-40, and one [Nordic Drill] DRC-10-A.”

The water well industry has benefited from the DR drilling method since Barber Industries introduced it in 1979. The method is well known for its ability to drill straight holes through the stabilization effect by rotation of the casing. In 1993, this technology was acquired by Foremost Industries of Alberta, Canada.

The primary distinguishing feature of a DR rig, according to Foremost, is a lower rotary drive that is used to advance steel casing through unconsolidated overburden. Rotational forces are transmitted to the casing via power-operated jaws.

A carbide-studded shoe, welded to the end of the first piece of casing, enables the casing to cut its way through the overburden. A top-drive rotary head simultaneously handles a drill string equipped with either a down-the-hole hammer or bit to drill the center. Direct air circulation is often used, but flooded reverse circulation is possible.

In Quebec, Canada, many drilling companies near Groupe Puitbec are being sold because their main driller has quit. But with DR technology, younger people have expressed interest in applying to work in the industry, says Simon Massé, president and driller/hydrogeologist for Groupe Puitbec in Quebec.

“With a lot less experience, a lot less skills, you’re able to do better than a well experienced driller in a better time,” Massé reports. “It’s the way to work [like] using a writing machine versus a computer. A horse versus a tractor.”

Nordic Drill is a department of Groupe Puitbec that manufactures DR rigs and offers DR conversions with its lower rotary drive kit (CR-10, Conic Rotary-10 inches). It is also working on a Conic Rotary-8 inches (CR-08) lower rotary drive kit.

As of January, Nordic Drill had five DR conversions currently planned for 2023 (Schramm T450, Driltech DK25, Ingersoll Rand T2, EGT MD515, and REICHdrill T-650 WII) and its lead time was April. Its goal is to complete 10 total conversions in 2023.

The five current conversions will be modified either by the client, supervised by Nordic Drill, or completed 100% by Nordic Drill. The company has posted project updates on past conversions on Facebook’s Water Well Guys group and will do so again with these five conversions.

“We’re now having a lot of calls from people who have rigs that work fine, but they want to have an easier life, easier drilling season, and they asked us if we can do it. We now have almost all the models,” says Jeremie Comeau, project manager and designer for Nordic Drill, in November 2022.

Chad Grignon, driller/owner of Pine State Drilling Inc. in Athens, Maine, fits the above description. He was convinced a change was needed with how he operated and converted his 2016 REICHdrill T-650-W LEGEND 3 rig to dual rotary in spring 2022 (see shaded sidebar).

Grignon, who never operated a DR rig prior to the conversion, is naturally adjusting to the method and learning every day.

“I’ve mud drilled back in the ’80s and ’90s, run a casing hammer since the early 2000s, but DR removes the need for a big rig and creates a safer, more controlled drilling experience,” Grignon explains. “We still use this machine like a conventional drill rig, and hammer some holes in to drop pipe if we can’t DR it.

“It’s not the perfect rig, but it’s the most perfect I’ve had yet in my opinion.”

(Left) Casing jaws when not in the lower drive. Circled in red are the replaceable tong dies that do all the work of gripping the casing. (Right) Bottom view of the lower drive that grabs the casing. The rod that is sticking through from the top is the quill that is attached to the top-head. The jaws are in the open position here and casing slides up into the lower drive. (Far right) Beecroft switched from stick welding to wire-feed welding and didn’t break a casing joint in 2022 doing one pass. Beecroft says wire-feed welding is easier to teach someone who is new to welding and believes it is becoming more popular in use. (Inset) A heavy-duty 6-inch ballistic casing shoe. Photos courtesy Beecroft-Danwell.

DR Conversion Questions Answered

Before detailing some of the DR advantages, the idea of modifying a rig to this method elicits some key questions. According to Massé and Comeau:

  • The average cost for the lower drive and modification is $135,000. The kit includes the lower drive itself, main brackets to fix the lower drive to the mast, cylinders to move the lower drive, drawings and measurements, main hydraulic components, and casing jaws. Add-on options include a discharge swivel, different sizes of casing jaws, a cyclone, and more.
  • The modification can take four to eight weeks depending on who is completing it (client, supervised by Nordic Drill, or completed 100% by Nordic Drill).
  • Standard stroke is 7 feet and, in some cases, can be more. It is mainly chosen by the strength of the mast and the interferences.
    “We always try to keep the travel of the lower drive in the pivoting point of the mast as it is the sturdiest part,” Comeau says.
  • The speed and torque of the lower drive is variable. Nordic Drill’s new standard is 10,730 feet-pounds and 0-17 rpm. Speed and torque are inversely proportional.
    “With time, most customers seem to prefer speed to torque,” Massé says.
  • The lower drive has a capacity of 35,000 pounds of pulldown.
  • The lower drive has a capacity of 23,000 pounds of pullback.
  • With a rig that already has a compressor driven by the deck engine, some might wonder where the additional hydraulic flow comes from. Most of the time, Nordic Drill adds a hydraulic pump to have a dedicated circuit. If not possible, it can divert some oil from the original circuit.
    “Running DR includes the fact that a lot less power is needed on top drive [rotation and travel],” Massé says. “Also, when casing is running it is mostly in overburden, the compressor doesn’t take a lot of power. Power has never been an issue.”
  • Nordic Drill offers drilling support following the modification.
    “When the client is doing the first well and sending photos of samples to know if he can use a screen, that’s the kind of support we can offer afterwards,” Comeau says.

No. 1 Advantage: Advancing Through Tough Overburden and Boulders

Mainly designed for 6-inch water wells, DR has proven to be effective in drilling a cased hole in unconsolidated formations (sand, gravel, cobbles, and boulders).

“The reason that dual rotary drilling is taking off is that every drill can drill the easy ground [solid rock] but almost every drill struggles when it comes to drilling the overburden,” says Derek McGladdery of Derex Inc., which manufactures DR rigs in Alberta, Canada. “The DR just makes the overburden much easier to case off.”

A first-time exhibitor at Groundwater Week 2022, Derex began making rigs in the 1990s, but it didn’t find its momentum until pairing a smaller drill with the lower drive. The Derex 1340-14 DR rig with onboard air (600 cfm/250 psi) on a single-axle truck has been the most popular thus far among its rig models.

“The most asked question is how accurate are the samples and can you see the formations,” McGladdery shares. “People are always amazed when they truly can see what they are drilling through and can find water in formations that are inches thick.”

Brant Beecroft of Beecroft-Danwell Co. LLC in Frederic, Wisconsin, believes in DR and took delivery of his Derex 1340-12 DR rig in May 2022.

“We are a small company. We are not ever looking at running more than one rig,” Beecroft explains. “To be able to have a rig that I know that I can get through whatever I need to get through, and we’ve got some pretty bad stuff here in northwestern Wisconsin, I never had to worry too much that I could get it done.

“A dual rotary drill rig is not much different than drilling with a drill rig using a casing hammer with air as far as the basics of the air rotary method, but I believe you can install your casing straight and keep it straight. The casing will stay straight because you will be able to drill through the boulders, the cemented gravels, the cobbles, and you will be able to keep advancing the casing.

“I have drilled through solid trap rock ledges that were 1 to 5 feet thick and on the other side were soft heaving sandstones. I have drilled through boulders as big as the cab on my drill rig. It has been incredible.”

Beecroft, a fourth-generation contractor who only knew cable tool drilling, switched to DR in spring 2017 when he took delivery of Nordic Drill’s first-ever DRC-10-A crawler rig (which drills with 10-foot rods). Prior to that he spent time watching and learning from Tim Butterfield of Butterfield Drilling & Irrigation Inc. in Somerset, Wisconsin. Butterfield operates Foremost DR rigs and also drilled wells for Beecroft when he couldn’t complete them with his cable tool rig.

“I have a relative who currently drills with a mud rotary. From time to time, we drill wells for him,” Beecroft says. “The rig loses circulation, a hole collapses, or the rig just can’t get through it. I have another relative who drills with an air rotary with a casing hammer, and I have watched him struggle trying to pull the casing back, trying to telescope a screen, it just wasn’t working. After watching these methods compared to the DR method, I knew I was going to buy a DR and I have not ever regretted that decision.

“To be able to telescope a screen by grabbing the casing and slowly rotating—whether it’s continuous or rocking it back and forth and just pull the casing back—it’s been very simple for us.”

Prior to using DR, Beecroft resorted to using dynamite many times to get casing through boulders that many times resulted in bent/drifted casing. He used to not travel for work but that changed because his Nordic Drill DRC-10-A crawler rig proved to be effective in difficult formations. His company ventured to areas known for hard drilling where drill rigs with casing hammers are commonly used, and bent and drifted casing are also common. The mud rotary drill rigs were not able to progress through cobbles, ledges, or boulders.

“There is always a learning curve for every different formation that you’re drilling through,” Beecroft says. “Once I learned, which wasn’t very difficult for the soft formations, a little more learning needed for the hard formations, we [employees and myself] were amazed because we were going through tough formations that nobody wanted to drill or could not get through.

“There was no clay, no sand, no water, just large road gravel coming out the back of my rig and the penetration rate was great. While I was drilling there, the casing was not locking up or torquing out, the casing was not chattering, everything was running smooth, and both the upper and lower drives were running at low torque.

“That’s where the fun comes in for me is seeing that I can get through it. I don’t have to worry anymore. It doesn’t matter where I’m drilling, I know I am going to get through whatever comes in front of me.”

In the challenging geology of the Pacific Northwest, Pierce Kiltoff of JKA Well Drilling & Pumps in Monroe, Washington, recently had Atlas Manufacturing convert his T3W rig to dual rotary as a prototype.

“I’ve drilled at least 200 feet of boulders and volcanic outwash at the base of Mount Rainier in Seattle,” Kiltoff says. “I’ve set 6-inch 140 feet into volcanic tuff and basalt, drilled 10-inch through alluvial outwash, including boulders, and then pulled it back out.

“It’s a good setup. All in all, it’s fast, significantly faster than my [former] DR-24, and I’d say as fast as a casing hammer in easy stuff. I’ve been as deep as 300 feet with casing and still had steam comparable to a DR rig.”

But Kiltoff says finesse is needed.

“The DR doesn’t require you to push the casing in, you’ll just break or bend stuff and cause yourself issues,” he explains. “Put in torque limiters and gauges so you can ease your way into and out of situations.”

No. 2 Advantage: Better Penetration Rate Increases Fuel Efficiency

Friction is the top commonality among all rigs, and if there is too much of it, penetration can even stop.

Penetration rate depends on friction, depth, casing size, bit selection, geology, water table, hydraulic torque, hydraulic speed, and hydraulic pulldown just to list a few.

Massé of Groupe Puitbec says DR’s increased penetration rate leads to a better consumption per foot. This can thus lead to increased fuel efficiency.

“The penetration rate is superior I would say 95 percent of the time,” says Beecroft who has experience solely drilling in northwestern Wisconsin. “There are certain formations where driving casing is faster, but the formations generally don’t last long.”

At an idle, Beecroft is burning five gallons an hour with his Derex 1340-12 on a 350-horsepower Peterbilt truck when both the air compressor and rig are running at the same time.

“While I am drilling and keeping the rig below 1500 rpms, I’m burning seven gallons an hour,” he shares. “If I am drilling with a hammer, I’m burning between nine and 12 gallons an hour. Still very efficient.

“I was talking with a friend who has Foremost drill rigs about fuel consumption one day. I was surprised at what he told me he burned for fuel. I thought they would be burning 30, 40, 50 gallons of fuel an hour since they are big rigs, drill fast, tons of power . . . and he’s burning around 22 gallons an hour. That’s pretty efficient.”

Many DR drillers like using a hammer for all their drilling while a few opt for a tricone bit, says Beecroft, who uses a sealed bearing tungsten carbide insert medium-length toothed tricone bit for most of his drilling. In gray clays, Beecroft will sometimes switch to a sealed bearing mill tooth tricone, and he only uses his hammer for basalts, granite, or big boulders.

“It costs me more money to drill with a hammer bit, and for my types of geology, I would flood or lock up my hammer with fine sands and silts because I am usually in water by 50 feet or less and my average well is 150 feet deep with heaving sands and gravels,” he explains.

“Hammer drills do not work well in those conditions for me. Hammer drills also have a slower penetration rate in clays than a tricone around here.”

No. 3 Advantage: Versatility

With a DR rig, the driller is able to drill at any depth up inside the casing, at the bottom of the casing, or drill out the end of the casing if need be.

“I have a small DR drill rig, so I do not have as much drill rod play as other DR drill rigs. For me, 2 feet has been perfect for being able to feel out the bottom of the casing,” Beecroft shares. “The short rod that is attached to the top drive that is used to make every new rod connection is called a quill. That is how much rod play I have to drill out the bottom of the casing, but I can drill at any depth up inside of the casing.

“On the smaller DR drill rigs, 2 feet is very common. On a Foremost, 4 to 6 feet, from what I have seen. They have more rod play because the mast is much taller, but you need to know where the bit is at. The quill can be customized to the driller’s needs.

“You have to know when the bit is exactly at the bottom—not extracted up into the casing, not sticking out the bottom, you need to know exactly where that’s zeroed out—I memorize how much drill rod should be between the top drive and discharge. I have seen others use tape or paint. That tells me if the bit is at the bottom of the casing or not, so I can decide if I want to be up further in the casing, or if I want to be out the bottom of the casing and that is my starting point.

“Another advantage with a dual rotary is that you can drill with a plug in the bottom of the casing. Also, for screening, you don’t have to clean the bottom of your casing out completely. You can flood or fill the casing with water, keep a 1-, 2-, 3-, 4-, or 5-foot-deep plug in the bottom of the casing so that sand or gravel can’t heave when you’re tripping rods out.”

One advantage or reason to drill up in the casing is if there is concern with cross-contamination from the upper formation to the lower formation. One other reason is heaving sands. If that’s the case, Beecroft says to keep a plug in the bottom of the casing and follow the steps he mentions above on prep for screening.

“When I am drilling and encounter bedrock, I drill with my bit outside the casing so that I can seat the casing into the bedrock to make a good seal,” Beecroft explains. “I drill with my bit 2 feet out the bottom of the casing because with a dual rotary you want your bit to do the work and not the shoe. The shoe is going to do some, but your bit should be doing most of it.”

With multiple spots where the driller can hold the bit for different reasons, Beecroft says a driller has the luxury of many options when operating a DR rig. “They are very versatile,” he says.

No. 4 Advantage: Real-Time Sampling

When using DR, all the cuttings that rise up the annulus between the drill pipe and casing are diverted through a discharge swivel, which attaches to the top of the casing, according to Foremost.

A cone seal prevents cuttings from blowing by as the drill pipe rotates. Real-time cuttings are directed by a flexible hose to a dumping point or optional sampling cyclone.

For simplicity’s sake and to minimize equipment on the rig, Beecroft recently switched from using sieves to a square-end shovel to examine the drill cuttings.

“It has kept them [employees] out of the overspray,” he remarks. “It’s fine when the discharge pipe is only 5, 6 feet off the ground, but when the discharge pipe is 15 feet off the ground, the pattern gets wider and you’re going to get wet; with a shovel, we were able to see all of our cuttings accurately and stay dry and warm.”

The real-time sampling advantage has allowed Beecroft to drill shallower wells in areas that are known for deep wells. There are small zones of clean water-bearing material in between layers of clay from 1 to 5 feet that Beecroft can see using the DR method.

“Other rigs are drilling right through it,” he says. “They don’t even see it, so another advantage of having that lower drive is being able to extract the casing immediately. I can go from pushing casing to pulling casing back out of the ground in seconds. The water-bearing formation might be delayed slightly, but you are going to see something different like sand, sand and gravel, or water coming out of the discharge and then it will go right back to clays.

“I can literally stop drilling in a second, pull the casing back, find these zones, and it’s very fast. I can play with the zones, and if I decide to stop there and screen, I can just set the casing on top of the clay.

“I fill the hole with water; now I know that the hole is going to be clean to the bottom of the casing. So, what I do is set my casing on the clay so that I don’t have to deal with any heaving material. I have already played with the zone, I measured it. I know exactly how many feet of sand and gravel or just sand I have, and I know where the zone starts and stops. I actually pull my casing up about 6 inches so that I have water-bearing material at the bottom of the casing so as to not wash out
any clay and get silt from the clay formation below after I screen.”

Beecroft, who has a high water table (20-50 feet to water on average) in much of his territory, often detects vibration and noise from the teeth on the drill bit and casing.

“I drill through big boulders, tight gravels, and I have heard the casing make an awful squealing noise—that is the resistance on the casing,” he says. “Then all of the sudden the sound and vibration stops, and everything stops chattering. It is obvious that the formation changed there, so I stopped drilling and played with that zone. Is it clay or is it sand? Why did it loosen up?”

No. 5 Advantage: Prepping to Set Screen/Clean Out the Hole and Well Development

Beecroft believes prepping to set a screen with a DR rig is easier than using an air rotary with a casing hammer.

Whereas a bailer is often needed to clean out the plug material, which requires water to be added to the casing to be higher than the water table to prevent heaving sand, Beecroft has a different way.

“I let the hole heave as I bring my bit up higher into the casing, about 15 feet,” says Beecroft, who screens most of his wells that are finished in unconsolidated material. “The bit must be rotating at all times. As I am doing this, I turn my water injection pump on to the highest injection rate, and then I slowly reduce my air injection until I am no longer injecting air. I use a 20-gallon per minute pump. I inject water until I have water flow coming out the discharge. I will then start advancing the bit 3 to 5 feet at a time to float the material out that heaved into the casing.

“I will leave maybe a 2- to 3-foot plug at most in the bottom of the casing, but zero feet is best. I probably have 15 to 20 feet of material in the casing from heaving and I am floating that material out from the bottom of the well to the top to remove that material. We’re not using air; just water. Just basically jetting it out.”

With DR’s ability to extract and put casing back in, after Beecroft trips his drill rods out, he measures and knows how deep the hole is supposed to be.

“If I still have a 2-, 3-foot plug in the bottom of the casing, I fill the casing to the top with water, grab the casing with the lower drive, and lift it out of the ground,” he says. “When the well starts to take water—and if it takes a lot of it, it sounds like a funnel—I rotate and push the casing back down in the ground.

“I am using water weight to push the plug out and most of the time I only have to do it once or twice depending on how much has heaved up into the casing. You can’t do that with other rigs because these guys who are running casing hammers or hammer bits to drive casing, they don’t have the ability to extract that casing very fast and they can’t put it back in very fast.”

Beecroft says the main principle of flooding the hole and filling it to the top and extracting the casing is that it must be done fast.

“A dual rotary is the only rig that can do that,” he continues.  “The water weight just pushes that plug right back out into the formation. Usually, I either have a clean hole right down to zero inches of material in the bottom, or 6 to 12 inches, but when I push the screen down to the bottom, I will just push the plug out anyway because the formation is soft and loose from adding so much water to it.”

Compared to mud rotary, well development with DR is naturally much faster because there isn’t mud to develop out of the formation. Beecroft says wells in his area are not completely free from mud, which often leads to well performance issues.

“I see higher drawdowns in the wells, the wells don’t produce as good,” he shares. “My development time is going to be a lot faster with a DR, which means I am not burning as much fuel.”

No. 6 Advantage: Makes Drilling Fun and Reduces Stress

With these advantages and others that are too lengthy to list here, DR makes drilling fun.

Beecroft, who also serves as a volunteer fireman in his township when not drilling, has followed contractors converting to DR on Facebook’s Water Well Guys group. He’s noticed this advantage.

“One guy I know who put on the lower drive loves it, and it looks like he’s having fun with it,” he says, “and that’s kind of what a dual rotary is: it’s not really going to work. It’s actually fun to run the dual rotary.”

Mike Steffen, owner-operator of Steffen Well Drilling in Ontario, Canada, went from drilling with mud rotary to a ring bit casing advance system to DR. The Ontario Ground Water Association Board Director took delivery of a Derex 1340-14 DR rig after Groundwater Week 2021.

“The biggest thing I’ve found with the one I run is it greatly reduced my stress level, definitely increased profits, and I do a whole heckuva lot less work,” says Steffen, who disputes the notion by some that DR can only be used with air. “I can get more done in less time with less stress.

“Well, you show me a rig that’ll do that and beat my rig, I’ll sell my rig and buy that.”

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Doug McConkey, a DR consultant who started Fraser Valley Drilling Consultants in 2017 in British Columbia, Canada, created the Dual Rotary Drillers Facebook page in 2020. It’s been a helpful platform for contractors to network or get answers to questions.

“I know I get a fair share of questions through Messenger [from Facebook],” McConkey says, “and I suspect some of the other experienced members do as well.

“My favorite thing about DRs, speaking about Foremost rigs, is the lower drive. It allows you to case off overburden with relative ease, and issues you may encounter with a typical top-drive rotary rig can often be easily addressed with a dual rotary machine.”

Dual Rotary Conversion Alleviates Headaches for Maine Water Well Contractor
It didn’t take long for Chad Grignon’s preconceived notions about DR to change following the conversion of his 2016 REICHdrill T-650-W LEGEND 3 rig in spring 2022.

Grignon, driller/owner of Pine State Drilling Inc. in Athens, Maine, heard from others at past industry events that DR was good for casing but lousy on rod handling. That stuck with him until he heard about converting his current rig to DR where he could keep his rod handling and rod stripping speed.

“Now that I understand it [DR] and now of course running it, for me, it’s probably the best thing,” says the 49-year-old.

“I’m getting older, so I don’t want to work as hard. I just can’t. I won’t last, so we needed a better way to train our new guys, take the stress out of the machine, cut down on our fuel cost, cut down on our consumables, and this seems like this is the ticket for that.”

Due to cost and travel restrictions, Grignon elected to do the Conic Rotary-10-inch lower drive conversion from his shop and followed Nordic Drill’s drawings to convert the rig. He had assistance from his local machine shop and had the rig plumbed by another shop for four days  (see photos courtesy Grignon).

Part of the fabrication process included raising the top rotary head 5½ inches and moving the rod carousel out so it met with the top rotary head. This was due to the center of the lower drive being 5½ inches higher than where the current center point of the drill rod was.

Grignon’s rig became operational in June 2022, one month behind schedule, but he was still able to catch up to the company’s 2021 total wells (nearly 140 completed wells and nearly 12,000 feet of casing).

“What I like about it is there’s no effort, you just let the machine do the work and you basically let that thing fall on float and it’s just kind of cutting its way through and you’re just kind of drilling the plug out as it’s dropping,” he says.

“One job we put in, we timed it, we put 186 feet of casing in 4½ hours and it was some pretty nasty stuff. Boulders, gravel, everything you can imagine, and then we just let it hit bedrock and grind right into the bedrock and we don’t have to strip the rods out or anything; we just continue drilling once the casing is down and we put another diverter on and that makes our life easy too.

“They got another diverter that goes in, and jaws grab it on the lower drive, holds it in place, and you just start running your rods; you don’t have to shovel, you just blow it over into the containment. I’m pretty impressed with it.”

Grignon, who uses a cyclone on sensitive sites to keep the work area clean, has 8 feet of stroke length and drills with 20-foot rods. The largest casing he can run is 10 inches.

Grignon is currently using a 12-button casing shoe but open to seeing what else works. He’s been running an air hammer but will try a tricone bit based on the recommendation from Nordic Drill.

“That’s something I’ve got to try and learn a little bit about because my concern with it is I don’t think it will penetrate as fast as the air hammer,” Grignon says. “I don’t think it will in the rock, but they [Nordic Drill] claim it’ll do just fine in the different soils and handle it better.

“One advantage with a tricone is you’re not building up the air pressure like you are with a hammer. Like if you’re in clays and then that big whoosh, blowing out the pipe, you get that big surge, I don’t think you get it as bad running the tricone inside.”

Grignon, who was a member of the Maine House of Representatives from 2016-2022 to be a voice for the water well industry, believes his 2022 workload paid for the cost to convert his rig. He says with every job where they reached rock was finished the same day, saving him time and fuel, among other things.

It seems like Grignon is enjoying learning the DR method after never drilling with it until now. He’s taking the learning curve in stride.

“Just making sure I’m keeping the pipe straight all the time,” he says of one of the differences drilling with DR, “checking it constantly with a level, and just doing that all the time, trying to remember to do that. Little adjustment to make sure it stays nice and straight because the straighter you keep it seems to go in faster and better.”


Mike Price is the senior editor of Water Well Journal. In addition to his WWJ responsibilities, Price contributes to the Association’s scientific publications. He can be reached at mprice@ngwa.org, or at (800) 551-7379, ext. 1541.