Crowley, Parker, BP move liberty rig: unique rig for longest-reach wells ever drilled.

• Author: Orr, Vanessa
• Position: TRANSPORTATION

[ILLUSTRATION OMITTED]

To move a piece of drilling equipment from the Lower 48 to an Alaskan oil field normally takes a lot of time and planning. To design, construct and move a one-of-a-kind, 8,500-ton rig across the icy seas from Washington state to the North Slope takes a whole lot more.

This summer, BP Exploration (Alaska) Inc., Parker Drilling Co. and Crowley Maritime Corp. made history by successfully completing the Liberty Sealift, a project more than three years in the making. The goal? To build one of the largest pieces of equipment ever constructed for North Slope oil production, and then transport it from Vancouver, Wash., to one of the most remote places on the Last Frontier.

"Probably the biggest challenge that we faced was the coordination of all of the entities; we held a tremendous number of meetings to make sure that we were all in communication every step of the way," said Bruce Harland, vice president of Alaska Contract Services for Crowley Maritime Corp. "Another challenge was the short timeline: the rig needed to be designed, constructed, broken down, put on barges and transported to the North Slope during a very limited window of opportunity. If we missed that window, we'd be stuck for another 12 months."

BUILDING THE BIG RIG

According to Steve Rinehart, BP Exploration (Alaska) Inc. press officer, it was no small feat to create such a big rig. "A land rig didn't exist that was capable of doing what we wanted to do, which was to drill eight miles or further horizontally, two miles deep," he said. "To do this requires extraordinary capabilities. What resulted was a really big piece of machinery that takes a couple of barges to haul."

The massive rig weighs 8,500 tons, including all of the piping and rigging. It has eight 2,640-horsepower engines that generate 16 megawatts of power, and includes a pipe barn large enough to hold 90,000 feet of drill pipe and well casing. The top drive (the motor that twists the drill string) is rated at 105,000 foot pounds of torque.

"The rig is unique in that the hydraulic capacity, torque capacity and pipe handling capabilities are designed for very long reaching wells," said Joey Husband, Parker Drilling Co. Alaska general manager. The rig is made up of a drill module, a pipe barn module that houses all the casing and drill pipe, a drilling service module that contains the utility package, and the power module containing the engines.

"All of these modules are connected together to...