Completing A Challenging Directional Drill In The Marcellus Shale
Your geologists found natural gas hiding thousands of feet underground. Your legal team negotiated rights of way with landowners. Your drilling team went down a mile or so, made a horizontal turn and “fracked” the shale bed, releasing the gas. Your well is producing. So now what?
Now you have to get the gas from the wellhead to the waiting world. It means laying gathering lines from the wells and connecting them to larger distribution lines. It means that every time you have to cross a stream, wetland, road, mountain or other obstacle, you’ll have to employ horizontal directional drilling (HDD) technology. That is, you will have to bore beneath it. In northeastern Pennsylvania, it means you’ll bore - plenty.
Trenchless technology covers a wide range of methods, materials and equipment for the installation of underground infrastructure with minimal surface disturbance. However, combine drilling underground with negotiating topography and you have the recipe for challenges which raise the question: “is this possible?” In one 8½-mile stretch Linde Corporation and Gabe’s Construction Company completed 13 different bores traveling more than three miles. It took place in an area in Susquehanna County that crews from the two companies now fondly refer to as “Death Mountain.”
Liberty Park’s Unusual Bore
A variety of issues complicated the so-called Liberty Park bore. First was the distance of the bore, as it was planned to run 1,332 feet in length, underground. The bore would have to drop more than 100 feet to get under the stream and road and then come back up the other side at a two to one angle.
Space, Weight and Angle Issues
Then a new wrinkle appeared - a conventional pullback of the pipe couldn’t be done. Ordinarily, the pipe sections would all be welded together and the continuous string would be pulled back as one piece through the bore hole. This was not possible at Liberty Park because of space and weight factors. First, the exit angle was too severe. This was caused by right-of-way restrictions and by power lines just 150 feet from the entry point of the pipe that would be in the way if all the lengths were welded beforehand in the conventional style.
Officials with Linde and Gabe’s decided to weld the pipe together in sections while suspending each length of pipe in the air during welding. Complicating the plan was the fact that each length of pipe was three sections of 42 feet each, just less than 130 feet in length. The 16-inch steel pipe weighs about 65 pounds per foot, which means each length of pipe tipped the scales in excess of five tons.
Gabe’s Construction, formed in 1942, has been actively involved in the trenchless field since 1989. Pittston-based Linde Corporation has a 14-year history in boring and claims it has never failed to complete a bore. “If we say we’ll do a bore, then we’re all in,” said Linde HDD Manager Fred Ostroski. “Once we start, we’ve never walked away from a job. We’ve known the people from Gabe’s a long time. They’re the same way.”
- Coatings, pipe joint
- Compressor components
- Contractor, pipeline
- Contractor, river crossing/ directional drilling
- Directional drilling rigs, large
- Fittings, valves: plastic
- Meters, flow
- Pigs, cleaning
- Pigs, intelligent
- Pigs, scraper/ sphere launchers/ traps
- Scada systems
- Ultrasonic inspection
- Vacuum excavators/ potholing
- Valves, ball
- Welding systems, automatic