Equipment:StraightLine HDD® RockEye Air Hammer 4.0 on a Ditch Witch® 2720 M1, with a Sullair® 1150cfm x 350 after-cooled air compressor.
The Challenge: Pinnacle Development, Inc., of Brighton, CO was awarded a tough 1000′ bore along a steep slope in the heart of the Rocky Mountains, northwest of Gunnison, Colorado. The company was to install a 4″ poly line to supply fresh water to the top of the mountain. Initial set up was recorded at 9700 feet above sea level. Working through late spring snow flurries, the crew prepared to make their shot down the mountain. Environmental factors were also of concern, and the stated goal was to leave the jobsite as they had found it – completely natural.
Concerns regarding changing rock formations and the ability to carry the cuttings up the mountain created the challenge. In addition, limited access to water on the exceptionally remote jobsite, compelled Pinnacle’s Rick Allison, to call on StraightLine HDD® and Lead Field Engineer, Ron Becker, with a 4.0 RockEye Air Hammer. StraightLine’s air hammer technology has been documented to use 90% less fluid, when compared to conventional drilling methods. By employing after-cooled air as the primary drilling fluid, Pinnacle was looking to prevent frac-outs, while drilling through solid mountain rock and minimizing their construction jobsite footprint on the surrounding environment.
After careful consideration the crew made the bold decision to attack the bore with two points of entry. The extreme angle down the mountain side and the precise steering required to hit the tie-in pit was the task of the day. Field Engineer, Ron Becker, explains, “At a 75′ drop per 100′, we started on the topside of the bore path and drilled a little over halfway. We then set up on the bottom side, what would have normally been our exit point, and attacked the bore uphill, steering through the rock and hitting our mark, connecting the pilot shots.”
Outcome: A successful bore was completed, as the precise steering of the RockEye Air Hammer System was tested on the steep slope of the mountainside. After-cooled air was the primary drilling fluid, mixed with a total of approximately 2000 gallons of water and one quart of foam on the completed 1000′ pilot shot. Twelve to fifteen minute rods were steered consistently through the mountain rock. “The goal was to efficiently complete the bore and not disturb the environment around us. We’ve done that,” stated Field Engineer, Ron Becker. “Due to the extreme remote location, hauling water up and then back down, the mountain was not something we wanted to do. In the end, we minimized what we needed up here to get the job done and we didn’t even have anything to haul off.” No frac-outs were recorded and the construction footprint on the surrounding environment was nonexistent.