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Large Rig Market Profiles: Carving A Niche In Rock
H&H Enterprises Focuses On Work In Difficult Soils
“Directional drilling plays a more significant role in pipeline construction in the Northeast more than in other areas,” he says. “In the Midwest, for example, most pipeline construction is in open country where big trenchers can go for miles without stopping. The Northeast is very different: regulations are very strict about where trenching is permitted and when it is prohibited. All road crossings have to be drilled or auger bored, and the geography creates a demand for HDD; auger boring sometimes is complicated because of changes in elevations. HDD simply is the only way many segments can be completed.”
Hockran says H&H jobs in the energy shale typically involve making two or three bores in a five to 10 mile segment of a pipeline route. The drill unit is set up on the low side of a road or river, drills under the obstacle and up the side of a hill or mountain where excavation can resume. Drills often are to depths of 50 to 150-feet, too deep for walkover trackers. Mud motors are used to go through shale and other rock, and wireline systems are used to guide the bore path.
A recent project southwest of Pittsburgh, PA, to install a segment of 16-inch diameter steel gas transmission pipe is typical of H&H energy projects. An American Augers DD220 with a mud motor was used to drill through solid shale and sandstone.
“The bore was 1,700 feet long under wetlands, a creek and up to an exit on the side of a mountain where it tied into pipe in a trench,” says Hockran. “The 8 3/4-inch pilot hole was enlarged in two passes with 20- and 26-inch hole-openers. Average depth below the surface was 60 feet. It took 10 days to complete the pilot hole. While drilling was under way, pipe was assembled along the right-of-way.”
Hockran says that in H&H’s experience, mud motors and conventional hole openers consistently work very well in rock found in the Northeastern U.S.
“We believe it is best for companies to purchase mud motors that drill in rock most of the time. We own and operate Adtech motors, but at times rent as needed,” he says. “We use a ParaTrack II magnetic tracking system from Prime Horizontal; we own and operate our own steering equipment.”
For rock drilling without a mud motor, Hockran considers the two primary options: conventional heads with TCI inserts and air hammers.