Sometimes big jobs call for big machines.
When Big Warrior Corp., based in Cleveland, AL, was faced with installing a 12-in. natural gas transmission line spanning 2,000 ft. (610 m) in solid rock, the company’s horizontal directional drilling (HDD) experts enlisted its biggest HDD machine — a Vermeer Navigator D200x300.
The 2,000-ft. bore happened to be just one section of a 5-mi. (8 km) bare steel replacement project that Big Warrior was hired to complete for AGL Resources Inc., a local distribution natural gas company. To maintain the integrity of its natural gas pipelines, AGL Resources surveyed and replaced all of its bare steel pipes with epoxy-coated pipes, which prevent corrosion.
In fact, just last year, Big Warrior used HDD to install 41,000 linear ft. (12,500 m) of 12-in. gas pipeline and 10,000 linear ft. (3,000 m) of 16-in. gas pipeline for AGL Resources’ Slashpine and Macon Peeking Pipeline Projects.
“Over the past four years, we have done quite a bit of work for AGL Resources,” said Blane Clark, vice president of Business Development of Big Warrior, which specializes in natural gas pipeline installation.
Overcoming Ground Obstacles
The most recent project involving the 2,000-ft. bore took place in Newnan near a residential subdivision. For most of the 5-mi. (8 km) project, Big Warrior crews used a Vermeer Navigator D80x100 HDD unit to install the new epoxy-coated pipe. But for the longest bore, Big Warrior Drilling Superintendent Thomas Dean knew he’d need the company’s largest rig. And as luck would have it, crews were able to save the most difficult bore for last because the 2,000-ft. shot would be for future transmission.
So several months later, Dean and his crews headed back to the Newnan job site with their D200x300, the second-largest HDD machine manufactured by Vermeer.
First, they mapped out a bore route using a Mark III locator system. The 12-in. natural gas transmission pipeline was to be installed in AGL Resources’ right of way, which was located approximately 150 ft. from the homes and separated by a wooded area (or buffer zone). Even though there weren’t any obstacles in the way of the drill route, Dean said trenching was not an option because the area was designated wetlands.
At first glance, it looked to be a long but clear shot. But that was not the case because the rocky soil conditions posed a different kind of obstacle for the crew.
Almost immediately, the crew ran into a granite-type rock as it began the pilot bore. From past experience working in regions around the world with hard soil conditions, Dean decided to use a mud motor and a drilling fluid with between 70 and 100 percent viscosity. This proved to be the perfect formula because the crew didn’t have to change the drill head once.
“It’s always a challenge when you drill in hard rock, so you have to be prepared for it,” Dean said.
Before pulling through the pipe, the crew performed a preream and a cleaning run. When it came time to backream, Dean said it used a 24-in. split-bit backreamer designed especially for hard ground conditions. While it didn’t experience any problems during the backream, Dean said it was a slow and methodical process that consumed 12 days of the three-week project.
In the end, Dean said the project was a success using the D200x300 because it had the power to complete the long bore in one shot. The crew also was better able to gain access to the hard-to-reach job site because the HDD machine was not trailer mounted. Maneuvering up and down the steep hills in the tight right of way space wasn’t a problem for the large HDD unit mainly because of its tracks, which provided excellent traction, Dean said.
Expanding with HDD
The project in Newnan is just one of several natural gas pipeline installation jobs Big Warrior has completed for AGL Resources.
Since being founded 20 years ago, the company has grown considerably to take on larger projects and employ 175 people in its natural gas installation division. Clark said it stays busy throughout the year, taking on jobs across the Southeast from Texas to Florida. Its territory also has expanded as far north as Chicago.
Clark credits some of the company’s success to its addition of HDD. Previously, he said the company subcontracted all of its HDD work. That was until Big Warrior owners found they were wasting time and losing money by having to work around other contractors’ schedules. That’s when the company purchased its own HDD machines and hired experienced operators to do the work themselves.
“Thomas Dean is one of the top drillers in the world. He’s worked in Holland, Belgium, Iraq and all over the world,” Clark said. “So if there’s a tough drill that needs to be pulled off, he’s one of the guys that’s called.”
Today, Big Warrior owns four Vermeer HDD machines, including the D200x300, two D80x100 Series II and a D50x100A.
Clark, who is responsible for pursuing work and negotiating contracts, said the company has used the units to perform natural gas pipeline installation for the state of Florida, Central Florida Gas, Enron and Peoples Energy.
“Owning our own drills is big because we can get very competitive with our prices,” he said.