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Vol. 12, No. 6 Week of February 11, 2007
Providing coverage of Alaska and northern Canada's oil and gas industry

Ultra ERD for Liberty

BP says will drill from Endicott island, with wells up to eight miles long

Kristen Nelson

Petroleum News

BP will push the drilling technology envelope with its newest development plan for the Beaufort Sea Liberty prospect.

Initially the company planned to build a drilling island at Liberty, which is five miles offshore, and move oil to shore in a subsea pipeline.

It would have been a Northstar-type development, the field’s resource manager, Carl Lundgren, told the Alaska Legislature’s House Special Committee on Ways and Means Jan. 31.

After reconsideration, BP decided in August of 2005 it would develop Liberty using extended reach drilling, from a drill pad onshore (see story in Oct. 31, 2005, issue of Petroleum News).

What Lundgren presented to legislators was a new plan — drilling from Endicott, eight miles to the west.

This ups the technology ante, moving from extended reach to ultra extended reach drilling.

“BP is proposing to develop the Liberty field using world-class drilling technology,” Lundgren said, calling Liberty “the most exciting oil project that we have in our Alaska business.”

The Northstar development in the late 1990s was based on an offshore island and offshore pipelines, Lundgren said. “But with advancements in drilling technologies like ultra extended reach technology, which BP has pioneered, we now can develop offshore fields like this in a much different way.”

Wells will be drilled from the easternmost drill pad at Endicott, on the Endicott satellite island. “We will then process these fluids through our existing infrastructure at Endicott,” he said, allowing BP to make use of existing North Slope infrastructure.

Endicott has the capacity

Endicott isn’t only in the right place; it has the capacity to handle Liberty: Endicott production peaked in the early 1990s at 120,000 barrels per day, Lundgren said, and currently produces less than 15,000 bpd.

Using Endicott helps with both costs at Endicott and costs at Liberty, he said.

Production from Liberty is expected to peak at 40,000 bpd, with a recovery target of 100 million barrels. The life-cycle cost of the project is some $1 billion.

Moving ahead with technology, permitting

Lundgren said $30 million is budgeted in 2007 for engineering studies, technology development and permitting work, with the goal of taking the project to a decision point this year and ordering long-lead-time equipment.

With final engineering and permit approval in 2007, the rig and facilities would be constructed in 2008-10 and drilling would start. In addition to rig construction, the satellite drilling island at Endicott would be expanded. First production would be in 2011.

BP holds the world record for extended reach drilling at its Wytch Farm development in the United Kingdom. The original plan there was to develop an offshore island, but instead BP chose to develop Wytch Farm with extended reach drilling from onshore. “And today we hold the world record in extended reach drilling,” Lundgren said.

The industry drilling envelope puts Wytch Farm at the outer edge of the ERD drilling envelope: Liberty wells lie outside the current drilling envelope.

It will be a step change in technology. BP is drilling out to 35,000-36,000 feet at Wytch Farm; at Liberty, Lundgren said, BP will be drilling out to 40,000 to 45,000 feet.

Lundgren showed legislators a sample piece of rock from the Kekiktuk formation, the rock BP will be developing at Liberty. He said the reservoir rock is world-class, with high porosity and high permeability. The reservoir quality is “comparable to what’s seen in the Middle East,” he said. In addition to great porosity and permeability, Lundgren said there is no shale in the reservoir and no clay to confine the flow of fluids.

BP expects to have 15,000 to 20,000 barrels a day coming into the well bores. “These are very large producing wells,” he said.

New rig

In an October 2005 interview, BP talked about the plan to drill Liberty from shore, some five miles from the drill pad to the reservoir. Gary Christman, BP’s Alaska drilling and wells manager, said then that BP would need a bigger rig for Liberty. “The equipment we have (on the North Slope) does not have the capability to do this work,” he said.

Hoisting capability, pumping capability and the top drive would all need to be larger, Christman said: “Everything is bigger. It’s just super size everything we have.” Nabors Alaska Drilling’s rig 33E at Northstar is probably “the biggest piece of equipment” on the slope and in terms of measured depth the Liberty wells (at the five-mile length then being discussed) would be “almost double the total of measured depth drilled from what we have at Northstar.”

It’s “double the well-path length” and “translates into different sizing issues” that haven’t been calculated yet, Christman said in the 2005 interview.

With wells going out five miles, hoisting requirements would be about twice the loads at Northstar, pump capacity about three times Northstar and torque probably double, he said.

Detailed design, Christman said, would be needed before exact numbers would be available, but hoisting capability would probably be 1.5 million to 2 million pounds hook load capability, up from around a 750,000 pound maximum available on the slope now.

Such a rig wouldn’t be any taller, he said, but “it will look bigger more in the sense of beefier.”

And, like most rigs on the slope, it wouldn’t be readily mobile. “It’s going to be pretty much a fixed installation that’s going to be purpose-designed for Liberty,” with a skid-rail system that would allow the rig to be moved from well to well on the pad.

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