A recent ruling on the Marcellus shale could bring the legality of thousands of oil leases into question. Several market experts have already weighed in on the ruling, Bloomberg reports.

"With this ruling, it is now not clear who owns the rights to Marcellus gas where there has been a 'mineral' reservation," Ross Pifer, director of the Agricultural Law Resource and Reference Center at Penn State's Dickinson School of Law, told The Associated Press. "The leases will still be valid, but they may not convey rights to the Marcellus shale."

Pennsylvania is the only state that does not classify gas as a mineral in reference to land and leases, Sean Moran, an energy lawyer at Buchanan Ingersoll & Rooney PC, told the media outlet.

Legal experts state that until the issue is settled, companies looking to drill will have to cope with uncertainty about whether they have signed drilling leases with the correct people, according to Bloomberg. An attorneys told the media outlet that the matter could take two years to be resolved.