Rock In Colorado Challenges HDD Contractors

September 2012, Vol. 67 No. 9

"There were boulders the size of trucks," he said. "Drilling through these conditions doesn't get easier but we have learned and continue to get better. The pilot hole isn't just half the battle because there is no partial victory. You have to ream the hole to size and pull in the product line or it is a failure. You always need a plan but must also react, matching the conditions encountered. Knowing what not to do is just as important as knowing what to do. It's not a case where more power is needed; anyone can bring in a bigger rig. HDD requires finesse and these conditions magnify that need."

Relying on experience
With Brotherton’s most experienced crew and guidance services provided by Chris Hale of Horizontal Technology Inc., the work began and the pilot bit drilled its way through the cobble and boulders. The plan was to get through the trouble that had been encountered at the entry and then transition into solid rock before leveling off and directing the bit back up to the exit with as few trips as possible.

At about 60-feet deep, the formation changed and the driller started his initial build section coinciding with the original plan to level out at a depth of 150-feet. A complicated project became more so on joint 13 when 100 percent of returns were lost.

Israel Brotherton had the controls of the HDD on the day shift and Matt Brotherton handled the night shift. Jim made the decision to continue with the same bit and assembly used to work through the boulders and not trip out for the down-hole motor, which was on-site and ready. Through rotation and with skilled hands on the controls, working the bit, pushing ahead at the right times, both Matt and Israel were able to obtain the needed build rates to stay on the designed path. This "rock and steer" method had been developed and utilized successfully on previous projects. The plan was to continue advancing the pilot hole as long as the conditions allowed.

A motor may have drilled faster, but tripping out, then back in, was risky and would require increased GPM. Lost returns had already slowed production as the crew continually fought to refill water tanks and mix mud.