Natural gas production from 108 Marcellus Shale wells in Butler County has produced 66 percent more gas in the first half of this year than from the same period a year earlier.

According to figures from the state Department of Environmental Protection, county wells produced 14.6 billion cubic feet of natural gas in January through June this year, compared to 8.8 billion cubic feet in the first six months of 2012, and 4.75 billion cubic feet in the same period in 2011.

In the most recent reporting period, RE Gas Development had the most active gas wells, 58, and produced nearly 13.4 billion cubic feet of gas, which accounted for 91 percent of all gas produced in the county during the period.

RE Gas Development is an Evans City-based company that is a subsidiary of Rex Energy.

XTO had the second most active wells in the county at 26, which produced about 0.9 billion cubic feet, or 6 percent of gas produced in the county in the first six months of the year.

XTO is a subsidiary of Exxon Mobil.

Jackson Township led all county municipalities with 18 wells in the most recent reporting period, followed by Connoquenessing Township with 17 and Forward and Lancaster townships with 16 each.

This activity mirrored the level of impact fees these municipalities received.

Forward Township got $217,301; Connoquenessing Township got $160,150; Lancaster Township got $141,132, and Jackson Township got $138,827.

The fee amount, which changes from year to year, is based on the price of natural gas and the Consumer Price Index.

Overall, the county had 108 wells in the first half of this year, 77 wells in the first half of 2012 and 48 wells in the first half of 2011.

Across the state, drilling companies took 1.4 trillion cubic feet of gas from the Marcellus Shale in Pennsylvania in the first sixth months of 2013.