The Arbuckle formation produces oil and gas in Kansas. It also is a strong aquifer, which, in the past, has been a stopping point for hammer drilling, at least in the production hole sizes of 63⁄4 inches or 77⁄8 inches. L&S Well Service, out of Cherryvale, Kan., has conquered the Arbuckle with high pressure and volume air.

The Arbuckle also is a water-discharge formation. In earlier geological papers written on the formation, it has been described as having columns of oil and gas, which generally are near the top. It has produced 36 percent of the total oil from 21 oil fields over the last 100 years. Oil production peaked in the 1950s, tapering off to the point that, today, 90 percent of the wells produce less than five barrels per day.

The Arbuckle occurs at depths ranging from about 500 feet in southeastern Kansas to more than 7,000 feet in southwestern Kansas. Arbuckle strata thicken as a whole from north to south and are thickest, up to 1,390 feet, in the southeastern corner of Kansas.

Jim Lorenz, owner of L&S Well Service, says, “The Arbuckle is very porous with lots of water; it’s like drilling in the bottom of the ocean.” The aquifer is brine to the west. Farther east into Missouri, the elevation rises, and the Arbuckle actually produces fresh water, according to Lorenz.

Air drilling is the method of choice for L&S, and having a dependable booster is critical to the process. Lorenz says, “I have a mud pump, but haven’t used it in a year. I like air.” It’s his goal to finish a hole in a day to prevent watering out, or having to stop because the column of water reduces bit force on the rock. Increasing air pressure through the hammer discharges the head of water, allowing the bit to strike rock. L&S crews carry 2,460 feet of 41⁄2-inch Range III pipe with them, but generally don’t need to go deeper than 2,200 feet.

Going deeper into the borehole puts more water around the annulus of the drill string. The weight of the water at the bit, also called head pressure, requires more air pressure to overcome the head pressure to evacuate water from the hole.

To date, Lorenz says, “I am the only driller I know of who has air-drilled a 77⁄8-inch gas production well into Mississippian and Hayes formations.”

L&S operates a new Atlas Copco RD20 drill rig, equipped with a 1,250-cfm, 350-psi air compressor. Once drilling into the water, the head pressure begins to build. To evacuate excess water, L&S driller, Dustin Hirrlinger, engages the booster, but he admits, “I usually crank up the booster early because I can drill faster.” L&S runs a two-stage Hurricane booster, although it is possible to operate the unit in single-stage mode in more shallow situations.

The booster sucks air from the rig compressor and any auxiliary compressor, and converts it to a higher pressure. L&S runs a 6T 855 b2B 2000 Atlas Copco Hurricane booster with its RD20, which can produce 2,000 psi with 350 psi of suction. At 350-psi suction, the unit produces 2,400 cfm.

Hirrlinger says, “It is important to know what you’re doing when engaging the booster because the water discharges at such at high pressure.” He emphasizes the importance of chaining down the discharge line and starting slowly when unloading the hole. At idle, the Hurricane puts out 1,500 rpm, which equates to 600 psi.

Lorenz points out the necessity of having a booster. “Drilling a 77⁄8-inch hole takes twice the water that a 47⁄8-inch hole will. To lift the water, it takes a minimum of 1,000 psi to drill into the Arbuckle 400 feet. If you don’t have the air, you’ll lose circulation.”

Speed is a big advantage when drilling with air, but Lorenz also explains that he can get a straighter hole using air and a smooth-bore stabilizer. “When logging our holes, we have less than a 2-foot deviation where others can have a 20- to 30-foot,” he says.

Not all of L&S’s wells are disposal wells. Lorenz does everything from geothermal wells to gas and oil wells. Lorenz can work for anybody – and has in his 32-year career – but he likes working with smaller customers, and fills in with the big gas companies.