The Ohio Department of Natural Resources issued 156 permits in 2011 to drilling companies looking to capitalize on natural gas and oil in the Utica Shale.
The shale underlies portions of Ohio, Pennsylvania, Kentucky, Maryland, New York, Tennessee, West Virginia and Virginia.
ODNR issued 80 of those permits during the last three months of the year, including 32 in November.
Ninety-two permits were horizontal permits.
By drilling horizontally, drilling companies can extract previously untapped sources of natural gas and oil from underground rock formations such as the Utica and Marcellus shales.
There are currently 26 horizontally drilled wells, according to department documents; 16 vertical, or test wells, have been drilled.
Carroll County received the most permits, 43, followed by Jefferson and Columbiana counties, which had 19 and 16, respectively.
ODNR issued at least one permit in 18 counties.
Chesapeake Exploration LLC, a subsidiary of Oklahoma City-based Chesapeake Energy Corp., was the beneficiary of 111 of the 156 permits.
ODNR had issued only three permits during 2009 and 2010, according to department documents.
ODNR has granted a drilling permit in Green Township in Mahoning County to Chesapeake Exploration.
The permit location is on West Middletown Road between Salem-Warren and Youngstown-Salem roads.
ODNR issued a vertical-drilling permit, which means Chesapeake will need to acquire an additional horizontal permit if it wants to extract natural gas and oil from the Utica Shale.
It is the 14th-issued permit for Utica Shale drilling in Mahoning County. ODNR has issued both vertical and horizontal permits at six locations: four in Goshen Township, and one each in Milton and Ellsworth townships.
Only the Milton well has been drilled, officials said.