Costs Incurred for Property Acquisition, Exploration and Development

9 Months Ended

Sep. 30, 2013

Costs Incurred for Property Acquisition, Exploration and Development

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

	Nine MonthsEnded September 30, 2013			Year Ended December31, 2012
	(in thousands)
Acreage purchases	$	69,987		$	188,843
Development		727,386			1,049,129
Exploration:
Drilling		173,298			309,816
Expense		47,331			65,758
Stock-based compensation expense		3,013			4,049
Gas gathering facilities:
Development		40,626			41,035
Subtotal		1,061,641			1,658,630
Asset retirement obligations		(964	)		57,982
Total costs incurred	$	1,060,677		$	1,716,612

(a)Includes cost incurred whether capitalized or expensed.