Most drillers use fluids to optimize hole cleaning and, in general, make the drilling process go a lot easier. Given that, we wanted to talk to experts to get tips on making the most of drilling fluids. We didn’t have to go far to find those experts.

National Driller’s readers know Todd Tannehill and George Dugan, even if they have never met them in person. Both have written for the magazine’s Drilling Fluids column for years, talking about all things drilling fluids, from where bentonite comes from to spoils disposal, and everything in between. Both have now put years into helping drillers understand their fluids and get better results — in drilling applications from HDD to water wells to geothermal.

In our recent interview, they discuss changes in the abilities of and expectations of drillings fluids used on the jobsite every day.

Tannehill says fluids have advanced.

“We used to just talk about clays, and how to treat clays with like a synthetic polymer,” Tannehill says. “Now we’re getting down to the degrees of the clay. … Is it sticky? Is it swelling? Tell me about the clay. What’s it doing? … I think the products have become more sophisticated as companies like ours and our competitors put more and more money into research and development.”

“We can make anything you want, anything,” Tannehill adds. “It’s just whether the industry is willing to pay for it.” He says fluids companies try hard to strike that balance when advising contractors using their products. That’s a balance contractors try to strike too, but often with different results.

“A lot of times, the drilling fluids are the most under thought part of the job,” Tannehill adds. He says that often when drillers call with issues, the root of the issue lies in not right-sizing the quality of the fluid to the ground conditions. Naturally, drillers usually cite cost when try to “get away with” just drilling with water or water and bentonite – when additives or polymers would make a big difference in production. Sometimes, cutting those costs can get you stuck in the field and end up costing you more in the long run.

Backing up, Tannehill cut his teeth selling copiers and ended up in the fluids industry. George Dugan was pulled into the industry by a neighbor. Combined, they’ve spent decades advising drillers and drilling companies in their roles as technical sales managers at CETCO Drilling Products.

Soda ash is always the ground floor. And, number two, understand that different soils react differently. Understand the soil conditions: what’s going to happen in these various soil conditions and how to control that.

One of our first questions was what advice they have for new drillers.

“Soda ash is always the ground floor,” Dugan says. “And, number two, understand that different soils react differently. Understand the soil conditions: what’s going to happen in these various soil conditions and how to control that. Let the fluids control the ground conditions instead of ground conditions controlling your drilling, and you’re way ahead of the game.”

It’s not just newbies, though. Experienced drillers can have blind spots. One example: advancements in the industry.

“A lot of them that have their nose to the grindstone, they’ll kind of miss out on a lot of this new technology,” Dugan says. “You go out on a job with them and they’re getting into bad clay and they’re trying to run a long-chain, high-molecular-weight synthetic polymer to inhibit the clays. You say, ‘You know, all of the mud companies now have a low-viscosity version … that’s going to control your clay and not blind your screens.’ … That’s where it’s nice to get out and get in the field with these guys, see what they’re doing and makes these suggestions.”

Industry veterans all have stories. We asked them about off-the-wall calls or jobsite visits they’ve had. 

“Drilling fluid follows the path of least resistance,” Tannehill says. “I'll never forget a job that was being done up in the upstate New York region.”

He says the driller had a sudden — and thorough — loss of returns. That isn’t unusual. Voids swallow fluids all the time. Sometimes, pressure pushes the fluids above ground and you have a frackout. But it wasn’t so much about the loss of the fluids, but where they went.

“I was just trying to figure out where it was,” he explains. “There was no frackout or anything like that.” 

That’s when he saw a woman come running out of her house.

“She had a pink bathrobe on and fuzzy bunny slippers … and she came running out talking about her basement was filling up with mud. … I remember having to calm the homeowner down. What had happened was, fluids take the path of least resistance. They had put water pipes under these old foundation houses where they just chipped out a hole and then put a little cement patch around it. Over the years, that was gone and the drilling fluid found it was easier to go up that water pipe and into the basement. That was the first time I ever reached down and took a finger full of bentonite clay and ate it to show the homeowner it was safe."

We talked about advice for drillers, but what about drilling fluids professionals just starting out?

“I would tell you to keep an open mind and I would tell you keep learning,” Tannehill says. “I would say all of us, from the territory regional technical guys for all the drilling mud companies to the contractors to the engineers — especially engineers, since they’re the start of the spec, need to keep up on their continuing education on new products coming out, and you need to keep learning all the time.”

Education is good, but Dugan advises professionals starting out to be versatile.

“If it was just checking mud, it would be so easy,” he says. “But I think that’s the fun of this job. Somebody has to be a self-starter, because nobody's around to breathe down your back. Nobody can follow you around and tell you what to do when to do it. You've got to be a self-starter, have a good technical mind and understand the physics of what's going on and the chemistry behind it, and all that stuff. It takes somebody pretty well-rounded to do what we do.”

The Full Interview

We interviewed Todd Tannehill and George Dugan for episode 6 of our Drilling In-Site series. Our talk covered mud management, advice for folks just starting in the industry and fluids tips from their combined decades of experience in the industry. See the conversation at, or listen to the full-length podcast version at

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