BISMARCK, N.D. (AP) — North Dakota oil drillers and U.S. Sen. John Hoeven want federal geologists to reevaluate the amount of recoverable crude oil in the state.

Hoeven and industry officials say a new assessment by the U.S. Geological Survey likely would show stronger production potential and attract investment.

Hoeven wants the USGS to take into account other formations in western North Dakota’s oil patch that could be exploited using technology developed for the Bakken and the Three Forks directly below it.

The USGS once said two massive shale formations held the largest continuous oil accumulation it ever assessed. But the title was given to a formation in Texas’ Permian Basin last year.

A USGS spokesman says no decision has been made on whether to do a new study.