Energy pipeline construction often brings to mind big, powerful machines moving across frequently rugged open country digging trench in which pipe is placed.
However, in the past few years, horizontal directional drilling (HDD) has played an increasingly important role in building pipelines, making water crossings, boring under highways and railroad tracks, working in environmentally sensitive areas and installing underground pipe when excavation is not permitted or surface conditions make trenching impossible.
Of course, pipeline routes also go through urban areas where HDD offers multiple advantages over open-cut construction.
In the Marcellus play in the Eastern U.S., it is well documented that directional drilling is playing an active role in pipeline construction, being utilized in a variety of situations in both developed and rural areas and mountainous terrain.
Unlike Marcellus, the Eagle Ford shale fields in South Texas are almost completely in open country. There, too, HDD makes river, highway, and rail crossings, but a growing number of HDD installations are being made in areas which trenching would seem to be the most cost-efficient method of laying pipe.
Environmental concerns are a factor, but here they are not always driven by governmental restrictions.
“Many of the HDD installations are across areas of open country that could easily be trenched,” says Boyd Simon, P.E., division manager of Digco Utility Construction, LP, d/b/a Ranger Field Services.
“The land is used for cattle and horse ranch operations,” Simon explains. “Landowners here have become aware of directional drilling and that HDD eliminates most excavation and some are making the use of HDD as a condition of allowing access to their land. Livestock can fall in open trench, and also fall when stepping into trench fill that’s settled.”
Simon says much of the work in the area is installing flow lines from wells to storage tanks. Most are steel pipe in diameters of six to 8-inches. Distances range from 2,000 to 3,000 feet at average depths of 85 feet. Soil conditions across the region are hard clay, sandstone and traces of gravel.
Simon says most of Ranger’s energy drilling is as a subcontractor for a pipeline project’s prime contractor with about 30 percent of the jobs contracted directly to the project owner.
For pipeline work, Ranger uses Vermeer D330x500 equipment powered by 426-horsepower engines and developing 330,000 pounds of pullback and 50,000 foot pounds of torque.
“This equipment is well suited for the energy work we do in South Texas,” Simon says. “This is a booming area with smaller drills being used to extend utilities to new motels, businesses established to serve the pipeline work, and new housing. We have smaller rigs and do utility work, but most of those jobs are going to local contractors.”
Adtech 6 3/4-inch size mud motors are used to drill pilot holes. Support equipment includes fluid recyclers, frac tanks and vacuum trucks.
Water and other challenges
Directional drilling in the Eagle Ford shale fields has its challenges.
“HDD has to have water,” says Simon, “and that means trucking in in – sometimes from long distances – or paying local landowners for use of their water; a big difference from working in cities and towns where you just fill up from a fire plug. There are times that water has a big impact on our job costs. We recycle fluids, but it’s still more expense than typical drilling work, a major cost of a project.”
All personnel working in the area – not just HDD crews – face several common challenges.
“Ticks seem to be everywhere,” says Simon. “Work areas are sprayed down before we arrive, during drilling and pullback, and everything has to be sprayed again after we leave the area.
“Crews have to be paid for out time, travel and living expenses. It is difficult to find motel rooms, and when they are available, prices are double what they would be somewhere else. Camps have been set up, bunking six to a room. It’s not the best situation, but sometimes it’s the only option.”
Ranger has been working in Eagle Ford for four years. Typical of energy-related work is a recent project in Helena, TX, installing approximately 2,900 feet of eight-inch steel pipe. Access was through landowners’ field roads with mobilization and set-up requiring two days. The pilot hole was drilled in three days, three days were required to weld pipe, and three days were needed for backreaming and pullback. Demobilization required another two days.
A water line job at Carizo Springs, TX, was to install 2,500 feet of 18-inch diameter HDPE pipe. It required three days for mobilization and set up, three days to drill a pilot hole, three days to fuse pipe, five days for backreaming and pullback and two days for demobilization.
Established in 1993, Digco Utility Construction d/b/a Ranger Field Services specializes in the horizontal directional drilling installations beneath waterways, congested areas, highways and environmentally sensitive areas. Ranger HDD crews have successfully completed installations in excess of 11,000 feet with many projects in some of the most difficult geological conditions in the United States.
FOR MORE INFO:
Ranger Field Services, (337) 837-5447, www.rangerdirectional.com
Vermeer Corp., (888) 837-6337, www.vermeer.com
American Directional Technology (Adtech), 405-449-3362, http://patriotpdm.com