For the past five years, natural gas producers have used drilling technology to crack open the largest natural gas field in Texas.
Because of horizontal directional drilling (HDD) and hydraulic fracturing, natural gas producers have been able to uncover the gas deposits in the Barnett Shale natural gas field in Wise, Denton and Tarrant counties in Texas. Though gas deposits were discovered in the Barnett Shale decades earlier, natural gas producers didn’t have the tools needed to break through the ultra-hard rock in the region and tap into the highly valued natural resource.
But now that HDD and hydraulic fracturing are able to drill in some of the toughest soil conditions, including caliche and limestone, Texas’ natural gas production has increased substantially, largely in part because of the Barnett Shale.
Just last year, the Barnett Shale produced 368 billion cu. ft. of natural gas, enough gas to heat 1 million homes for about five years, according to figures compiled by the Texas Railroad Commission and the American Petroleum Association.
Not only has the Barnett Shale meant big business for natural gas producers, but utility contractors also have profited from the 1.3 trillion cu. ft. of natural gas that has been produced since the field opened. With the discovery of a natural gas field comes the need to install pipelines to carry the gas to customers.
Whether using HDD machines or track trenchers, utility contractors have found a formula for successfully digging through the hard rock in the Barnett Shale and unlocking the natural gas that lies beneath. Recently, two contractors at the site used the two different methods and obtained the same results.
The Trencher Way
Diamond H Trenching Inc., based in Denton, TX, is one of several utility construction companies in the Barnett Shale field installing gas pipelines. Roger Hennen, owner and founder of Diamond H Trenching, said his company has completed multiple jobs in the Barnett Shale and other gas fields in the area.
Hennen started in the utility construction industry in 1999 using track trenchers to install sewer and water lines. It wasn’t long after that he moved into specializing in gas pipeline installation.
“There are a lot of gas lines going in in this area, and we’ve been fortunate enough to get a lot of those jobs,” Hennen said. “There’s especially a big boom for natural gas in the Barnett Shale field.”
In Texas, the largest U.S. gas producer, 5.8 trillion cu. ft. of natural gas was produced in 2004, which accounts for about one-quarter of the 20 trillion cu. ft. produced annually in the United States.
At the Barnett Shale field, Diamond H Trenching was commissioned to run a 10-in. high-pressure gas pipeline 10,000 ft. Hennen said the job called for his two-person crew to use a larger track trencher that could easily cut through limestone and other hard rock found in the region.
His crew used the Vermeer T855 track trencher, one of three Vermeer track trenchers owned by the company. Hennen’s company also has a Vermeer T555 and T655 track trencher.
“We chose the T855 because of its power and chain speed, which allows it to cut through tough rock more efficiently,” he said.
The crew used a basic tooth pattern on the T855 to cut a trench 5 ft. deep. Hennen said he was extremely pleased with the production rates the track trencher yielded. The two-person crew worked 10-hour days, each day cutting more than 3,000 ft. In fact, one day the crew was able to clear nearly 4,000 ft.
“We figured the job was going to take four-and-a-half days, but we cut it in less than three days,” Hennen said. “These Vermeer machines are real cost-effective and operator friendly. We get a lot of referrals and repeat business because we don’t have a lot of downtime when operating them.”
The HDD Way
Not too far from where Hennen’s crew was working with the track trencher, another utility contractor was installing more pipeline in the Barnett Shale field using two horizontal directional drilling machines.
Joe McElreath Co., based in Gainesville, TX, was subcontracted to bid a job that required installing an 8-in. steel gas pipeline about 25 ft. under a drainage culvert. Like Diamond H Trenching, Joe McElreath Co. crews faced the same tough ground conditions. To tackle the job, they used the Vermeer D100x120 and D50x100A Navigator HDD units.
When founding his company more than 40 years ago, Joe McElreath, owner of Joe McElreath Co., said he never would have predicted that drilling technology and the industry would advance the way it has. In 1962, McElreath began installing utilities with just a backhoe. By the late 1960s, McElreath had moved into telecommunication work. In the early 1970s, he purchased a vibratory plow for placing cable lines
In 1993, McElreath purchased his first Vermeer HDD machine. But by the late 1990s, the telecommunication boom had waned and McElreath then focused on soliciting customers wanting other utilities installed. He has since bought several Vermeer HDD units, including a D7x11A, three 24x40A, two D50x100A, and a new D100x120.
“When our demand got bigger, we needed the power to go the distance through the rock. So we purchased bigger machines,” he said.
For the gas pipeline job at the Barnett Shale field, McElreath’s four-person crew used the D50x100A HDD machine to bore about 25 to 28 ft. deep. They had the D100x120 on-hand as support, just in case the job called for a larger machine. McElreath said they typically turn to the D100x120 when installing large pipe and boring more than 800 ft.
“The D100x120 can handle the larger jobs, which we’re getting into more and more all the time,” he said. “You have to change with the changing market, and that’s what we’re doing.”
The crew used the Vermeer Mark IV locating system to locate the drill head. McElreath said his crews didn’t have any problems boring through the hard rock and exiting on the other side of the drainage culvert. He also says they used Baroid Bore-Gel and pre-reamed with a 14-in. backreamer before pulling back the 8-in. steel pipe.
“Because of the depth that the pipe would have to reach under the running creek, it was more economical to bore rather than to open trench cut it,” McElreath said.
While Hennen and McElreath’s companies used two different drilling technologies to complete their jobs in the Barnett Shale gas field, both were successful in conquering the hard rock and installing the gas lines. And, just as there is a critical need for natural gas in the world, natural gas producers have discovered that there is a critical need for both HDD and trenching to acquire this natural resource.
(Tara Deering is a technical writer for Two Rivers Marketing.)