Costs Incurred for Property Acquisition, Exploration and Development

6 Months Ended

Jun. 30, 2013

Costs Incurred for Property Acquisition, Exploration and Development

(17) Costs Incurred for Property Acquisition, Exploration and Development (a)

	Six MonthsEnded June 30, 2013			Year Ended December31, 2012
	(in thousands)
Acreage purchases	$	31,049			$	188,843
Development		500,534				1,049,129
Exploration:
Drilling		141,838				309,816
Expense		27,818				65,758
Stock-based compensation expense		2,030				4,049
Gas gathering facilities:
Development		21,081				41,035
Subtotal		724,350				1,658,630
Asset retirement obligations		(2,385	)			57,982
Total costs incurred	$	721,965			$	1,716,612

(a)Includes cost incurred whether capitalized or expensed.