03-08-04

When the US Geological Survey releases its final numbers for northern Alaska's undiscovered, technically recoverable natural gas, the average estimate is likely to reach 211 tcf. That would be enough natural gas for a pipeline from the North Slope to deliver 5.6 bn cfpd to market for 100 years. No such pipeline has been built yet, however, because of uncertainty about whether it would be profitable enough.

The USGS has already released its estimates for undiscovered, technically recoverable gas on federal lands and offshore state land: 150 tcf. At the end of this year the agency will publish its estimates for onshore state and Native land.

David Houseknecht, one of the USGS' top research geologists, expects the number for state and Native land to be close to the 61.4 tcf average estimate for the National Petroleum Reserve-Alaska. That would bring the total to 211 tcf, a figure that does not include the 33 t to 35 tcf of known reserves in North Slope fields such as Prudhoe Bay and Point Thomson.
"The largest accumulations we expect in the National Petroleum Reserve-Alaska are approximately the same size as the known gas reserves in the Point Thomson field," Houseknecht said in his presentation at state legislative gas hearings in Anchorage. "They are pretty substantial accumulations.

"Every one of those four major gas plays in NPR-A extends across the Colville River into Native and state lands. They extend all the way eastward to the pipeline corridor.”

"So even though we have not finalized our estimates for state and Native lands and I therefore cannot be specific, the geology on state and Native lands is essentially identical to that of the National Petroleum Reserve-Alaska and it would not surprise me if, in a few months from now, we are releasing numbers that are the same order of magnitude as our NPR-A estimates."

The USGS estimates in NPR-A were 40.4 t to 85.3 tcf, with an average estimate of 61.4 tcf of undiscovered, technically recoverable gas resource.

"The upside potential could be much greater," Houseknecht said. Houseknecht's gas resource estimates for northern Alaska do not include undiscovered non-conventional natural gas. He said there are "huge non-conventional gas resources" in northern Alaska, such as gas hydrates and coal bed methane and that "a significant proportion" of these resources are located under or within easy reach of existing North Slope infrastructure.

The USGS is ignoring unconventional resources in its current estimates because their "recoverability potential has not been established," Houseknecht said.

He said that the USGS' gas resource estimates, although based on sound science, have not been confirmed by drilling. Proved gas reserves, however, are resources that have "been shown to exist in known reservoirs" and can be "expected to be produced," he said.

"It's highly probable the gas resources are there," said Mark Myers, head of the state Division of Oil and Gas, when asked about Houseknecht's estimates for northern Alaska.

How do northern Alaska's undiscovered gas reserves compare to the deepwater Gulf of Mexico?
The US Minerals Management Service estimates up to 55 tcf of undiscovered natural gas in Gulf water depths greater than 7,000 feet.

Source: Petroleum News