Taking a look at possible shale oil impacts

As part of its newly published assessment of North Slope shale oil and gas resources, the U.S. Geological Survey has taken the unusual step of publishing critical raw data such as play areas and estimated well drainage areas that the agency used as inputs to its assessment calculations, USGS geologist Dave Houseknecht told Petroleum News Feb. 27. As well as allowing people to check the calculations and construct shale resource scenarios for themselves, perhaps taking a preliminary look at the possible development economics, this raw data provides some interesting insights into the potential surface impacts of North Slope shale oil development.

Take, for example, the USGS data for the Shublik, thought to be the most promising North Slope source rock for shale oil development.

Assuming that the Shublik oil play becomes fully developed, that all of the development occurs in play “sweet spots” where wells are suitably productive, and that the sweet spots occupy about 15 percent of the entire play, approximately 1.1 million acres of the play might be developed. Then, assuming that one well bore could produce oil from, on average, 160 acres of the play, a total of 6,844 well bores would be required. Using directional and horizontal drilling, it might be possible to drill three to eight wells from a single one- to two-acre surface well pad — that would require 855 to 2,280 well pads, occupying a total of 855 to 4,560 acres of land.

—Alan Bailey