Power turns

Copyright photo: Warrior Manufacturing Services Ltd

Power turns

March 2015

 

Horizontal directional drilling for oil and gas is a hot technology, and one that requires drilling drives that are especially powerful, compact and reliable. Canadian manufacturer Warrior offers hydraulic top drive systems for these applications.

Over the last two decades, oil and gas drilling technology has evolved dramatically. Whereas twenty years ago oilmen only drilled straight down, the state of the art is much more demanding today. The industry demands boreholes that can change direction and run horizontally hundreds of meters below the earth’s surface. A horizontal well covers a much greater area than a vertical one – which decisively boosts the output per well. Additionally, horizontal drilling enables producers to reach oil and gas deposits that cannot be tapped from directly above.

Darrell McGrath is President and CEO of the Canadian drilling equipment manufacturer Warrior. “Nothing’s changed the deep drilling business like the development of directional drilling,” he declares. That also affects the drives, which must apply an exceptional amount of torque to the drill string when drilling sideways. As McGrath explains, “Because of that, when we were developing our top drive we decided against an offset motor with gear unit and instead went with the Hägglunds CA from Rexroth with fully variable speed. The concentric hydraulic motor drives the drill string directly. That gives us around 20 percent more torque.”

More compact for more possibilities

“The second persuasive argument for the Hägglunds CA motor was that it’s extremely compact,” McGrath adds. “Because of the direct drive, we can reduce the overall footprint of the top drive.” Drilling rigs come in all shapes and sizes. “Twenty, thirty years ago, it was not common to mount the drill string drive right in the mast,” McGrath recalls.” Back then, land rigs were still built with kelly drives rotated by the rotary table.” That is why older rigs typically have a derrick that narrows toward the top. That makes compactness a particularly decisive advantage for top drives, weighing up to 350 tons, especially in retrofit jobs. “We just recently installed our top drives in small drilling masts in Indonesia, because our competitors’ drives were simply too big and didn’t fit.”

Reliability and simple maintenance

Warrior Manufacturing Services Ltd. was founded in 2005 in Calgary, Alberta – Canada’s oil province. The company manufactures components for drilling rigs, including electric and hydraulic top drives, make and break machines, powered catwalks, offline stand-builders and drawworks. Warrior’s customers are based mainly in North and South America and Southeast Asia, and they place top priority on reliability and simple maintenance. This is particularly important for top drives. “If problems arise here, the entire rig is shut down. And shut-downs cost a lot of money in the oil business,” notes McGrath. That is another reason to use the Hägglunds CA motor: “From experience, we know how reliably it operates, and that Bosch Rexroth offers rapid, excellent service for it.”

Power turns

Top drive:

Top drives rotate the drill string. They have almost completely replaced the kelly drive system. Top drives in particular are advantageous when drilling long, horizontal sections.

Directional drilling:

In directional drilling, the borehole changes direction underground. This enables a single well to cover a large area and extract deposits that are out of reach of vertical wells.