Did you know that drilling rigs can walk? At least this one can. It's the ECO-Pad being used by Continental Resources Inc. to drill for oil in North Dakota. walking rig.jpg

The 800,000-pound rig walks on hydraulic feet between drill sites up to 100 feet apart. Rather than creating a four-acre drilling pad for each well, the rig's portability makes it possible to drill four wells from the same drill pad. That greatly reduces the amount of land that must be disturbed for drilling.

It also saves time. Usually it takes about one week to dismantle and move a rig to the next drill site. With the ECO-Pad, the rig can walk to the next drill site in about two hours.

A few years ago, many drilling companies began setting rigs on rails to slide them to the next hole. This practice has been used very successfully in natural gas formations in Colorado, and on the manmade THUMS Islands in Long Beach harbor where rigs slide along a circular track. But this might be the first time anyone in the United States has ever used a walking rig.

Continental President Jeff Hume developed the concept in the 1980s and registered it with the U.S. Patent and Trademark Office. "We're applying old technology in new ways," Hume told The Oklahoman.