Oil drilling activity in the Williston Basin has picked up where the activity of the 1970s and ‘80s left off. This has been made possible by advances in horizontal drilling, the evolution of enhanced oil recovery techniques and advances in equipment.
As major operators race to make up for the 30-year lull, one of the strategies they depend on involves hiring top hole contractors. These vertical drilling specialists with their truck-mounted rigs drill and case the wider, top portions of well profiles before sealing them with well heads. Conventional rigs follow behind to complete the well to total depth. This combined fleet drilling is referred to by some as the “spudder rig” method. Spudder rigs can mobilize much more quickly than conventional rigs to secure leases for the major operators.
Although work is plentiful, Craig Obermueller, owner of Craig’s Roustabout Services of Vernal, Utah, said he’s seen a few drilling contractors go home defeated. As he explained, success as a contractor in the Bakken—at least until Williston’s infrastructure catches up—seems to require self-sufficiency. “If you don’t bring what you need with you, you won’t have it.” That means having and retaining a competent workforce and using reliable drillings machines like Craig’s six Atlas Copco RD20 III and RD20 XC rigs.
In an isolated environment
Obermueller’s company is a prime example of self-sufficiency. First, Obermueller knows what is needed because he is no stranger to the region. He lived and worked in North Dakota in the mid ‘70s during the first boom. Obermueller has returned with Craig’s Roustabout Services, which has grown since its founding in 1981 to become a provider of a wide range of services to the oil industry. They serve the intermountain region from the Dakotas west and from the northern U.S. border south to Colorado, offering services in construction, blasting, trucking, roustabout, disposal, hydro excavation services and drilling.
For surface drilling over the Bakken, Craig’s combines small bucket auger rigs to set conductor pipe with their Atlas Copco RD20 drilling rigs. Four of Craig’s RD20 rigs are range III rigs with RD20 pipe. Two are RD20 XC rigs with hydraulic elevators for handling external upset pipe, or “bottleneck pipe.”
Three of the rigs are based out of Williston. At times Craig’s brings a fourth rig over from the Utah home office to meet surges in demand.
In the relative isolation of Williston, a 15-hour drive from the Utah office, Craig’s own technician performs almost all maintenance and repair for the rigs at the Williston headquarters located just west of the town, complete with service bays.
Since downtime sends a contractor’s clients to eager competitors, drill reliability is crucial. Obermueller said, “I just can’t say enough about these RD20s. They are that dependable.” Though he has had smaller models of other makes, he has used Atlas Copco RD20 rigs since he first expanded Craig’s drilling capabilities to bid larger, deep hole projects in 2006.
Eric Kay, general manager for Craig’s Roustabout agreed: “We’ve really had good success with them.”
Top hole efficiency
Obermueller said he is amazed at today’s well designs. “They are 20,000-foot wells—and 10,000 feet of that is sideways.” Yet, Obermueller said, wells like these that used to take major operators weeks to drill might take days now.
Joe Maguire, Craig’s drilling superintendent for its Williston operations, said they’ll move pad to pad in just 13 trailer loads. That includes solids-control components, a shaker box, two 400-barrel upright fluid storage containers, a pipe trailer, their wheel loader, a skid steer and then light towers and other jobsite equipment. In North Dakota, for some of the year, that includes bumper-mounted heaters to keep them working at minus 30 degrees.
Craig’s prefers to use bucket auger rigs for preparing the rat hole and setting 14- to 20-inch conductor pipe anywhere from 60 to 80 feet deep. Then the RD20 moves in.
Craig’s puts two crews of five on a hole working in two 12-hour shifts. One RD20 and its crews were set up on a pad to drill and case six holes 10 feet apart. Jobs in this area ranged from 1,800 to 2,220 feet. The current hole would be to 1,870 feet.
After the steel rat hole was set by the bucket auger, the RD20 moved over the hole with a bottom hole assembly that consisted of a 13 ½-inch PDC bit, short sub, 8-inch collar and 6-inch collar before the bottleneck pipe.
Phillip Lacombe, who has been with Craig’s five years now, kept rotation under 90 rpm for the first 500 feet drilled to make the straightest hole possible. Craig’s drilling crews take great pride in just how straight their holes are. But as a precautionary measure for collision avoidance, the client specified this pad’s holes be drilled 3.5 degrees from vertical.
“We know we can drill them perfectly parallel, straight as an arrow shooting for a bulls-eye, no interference,” Kay said. “But the conventional rigs coming behind us will drill them to a kickoff at 10,000 feet. Imagine: six holes 10 feet apart for almost two miles.”
To turn this hole, though, which required a mud motor crew, Craig’s called in directional specialist Leam Drilling Systems. The Leam crew put the mud motor on with chain torque wrenches mounted on the rig.
Each hole required about 600 barrels of clear well water to drill. No additives were necessary. Water was reclaimed from the 480-barrel shaker box to be reused for finishing a hole. If the next pad was near enough to make transportation cost-effective and would be drilled by the same driller, the water was centrifuged and carried to the next job. If not, then the water was taken to a prepared disposal site.
Although solids retrieved from these top holes were not from the overlying layers of the landscape and not in the production zones, Craig’s was required on this property to remove cuttings to a disposal site as well.
Maguire said drilling was routine from hole to hole. Crews worked 12-hour shifts. Once they reached the bottom, they would set for an hour circulating it to flush the hole. They performed a “wiper trip” to swab the hole. Setting casing generally took one 12-hour shift. Holes on average took a day and a half to drill. Moving hole to hole took about four hours.
Craig’s Williston crews currently have steady business from their clients, and they are studying logistics that might be required to meet demand, which could include adding another rig. Whatever the future brings, Craig’s will be ready for it, having whatever it takes to endure the boom since there appears to be no bust in available work.