ASSET RETIREMENT OBLIGATIONS: (Tables)

12 Months Ended

Dec. 31, 2012

ASSET RETIREMENT OBLIGATIONS:

Schedule of change in asset retirement obligations assumed

	2012			2011
Beginning of year	$	6,039,723		$	5,611,709
Additional liabilities incurred		1,448,063			1,308,122
Accretion expense		519,315			443,801
Obligations on properties sold		(511,730	)		—
Liabilities settled		(161,787	)		(155,558	)
Revisions to estimate		—			(1,168,351	)
End of year	$	7,333,584		$	6,039,723