Pipeline Border Crossing

Matching Right Rig For The Job Ensures Success
January 2009 Vol. 64 No. 1

Once the bore was complete, crews attached a 22 inch backreamer and performed one pre ream before pulling back the product. Due to the size of the rig, Dolan says a 22 inch backreamer was about the smallest size they could attach to the machine.

Unlike the drill head, Dolan’s crews had to switch backreamers as the ground conditions changed. “We would ream part of the way with one type of reamer, and then push out and hook up another type of reamer and then cut for a little while,” Dolan says. “We had to change reamers three times to make sure that we had the correct one for the ground conditions.” He says they opted for a beavertail reamer in the clay soil conditions and a mill tooth reamer when pre reaming through the sandstone and caliche.

After completing the backreaming, pulling through the 12 inch natural gas line didn’t pose any problems for the crews. “We really didn’t try out the rig’s pullback force because we had a good hole and the pipe slid right through,” Dolan says. “The biggest test it had was drilling the pilot bore, and it did a really good job of drilling the pilot. We didn’t have to push the rig real hard at all; it had plenty of power.”

Investing in the right equipment

Dolan’s equipment fleet includes a Vermeer D330x500, two D100x120s and two D80x100s. Dolan says he decided to purchase the D500x500 because it had all of the features he was looking for, such as a trailer mounted rig; separate power unit; and high torque, low speed hydraulic motors. “There are few electrical components, which we really liked for the simple fact that it’s much easier to work on and we don’t have to worry about electrical problems,” he says.

Construction contractors have heard time again just how important it is to match the right equipment to their task. But this is especially true in the trenchless industry where contractors are performing utility installation jobs of various sizes. To successfully complete longer bores, Dolan says contractors must ensure they have the correct size of HDD machine for the length of bore they will be drilling and the size of pipe they’ll be installing. “It’s making sure you have a good mud cleaning system and a mud pump large enough to carry your fluid at the volumes you need to a complete a job that long,” he says.