Property and Equipment

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment Disclosure [Text Block]

Note 3. Property and Equipment

The following table presents a summary of our net property and equipment balances as of December 31, 2015 and 2014:



	December 31,
In thousands	2015			2014
Oil and natural gas properties
Proved properties	$	10,245,195		$	9,782,337
Unevaluated properties	894,948			918,406
Total	11,140,143			10,700,743
Accumulated depletion, depreciation and impairment	(9,022,823		)	(3,679,883		)
Net oil and natural gas properties	2,117,320			7,020,860
CO₂ properties
CO₂ properties	1,187,458			1,162,538
Accumulated depletion and depreciation	(213,106		)	(183,646		)
Net CO₂ properties	974,352			978,892
Pipelines and plants
CO₂ pipelines ⁽¹⁾	1,749,538			1,733,562
Plants	543,681			536,002
Total	2,293,219			2,269,564
Accumulated depletion and depreciation	(230,297		)	(182,385		)
Net plants and pipelines	2,062,922			2,087,179
Other property and equipment
Other property and equipment	408,194			468,051
Accumulated depletion and depreciation	(186,979		)	(202,738		)
Net other property and equipment	221,215			265,313
Net property and equipment	$	5,375,809		$	10,352,244


(1)	Amount includes $114.3 million of CO₂ pipelines at December 31, 2015, that were under construction and not subject to depreciation during 2015.

A summary of the unevaluated property costs excluded from oil and natural gas properties being amortized at December 31, 2015, and the year in which the costs were incurred follows:



	December 31, 2015
	Costs Incurred During:
In thousands	2015		2014		2013		2012 and Prior		Total
Property acquisition costs	$	—	$	6,500	$	215,660	$	395,752	$	617,912
Exploration and development	24,814		95,397		40,090		30,206		190,507
Capitalized interest	28,302		21,179		22,916		14,132		86,529
Total	$	53,116	$	123,076	$	278,666	$	440,090	$	894,948

Our 2013 property acquisition costs were primarily related to the fair value allocated to the purchase of additional interests in the Cedar Creek Anticline (“CCA”). Property acquisition costs for 2012 and prior were primarily related to the fair value allocated to our Hartzog Draw and Thompson Fields, CO₂ tertiary potential at our CCA properties, acquired as part of the merger with Encore, as well as CO₂ tertiary potential at Conroe Field. Exploration and development costs shown as unevaluated properties are primarily associated with our tertiary oil fields that are under development but did not have proved reserves at December 31, 2015. The most significant development costs incurred during 2015, 2014 and 2013 relate to development in preparation for the CO₂ floods at Webster and Grieve fields, with the more significant development costs incurred during 2012 and prior relating to development in preparation for the CO₂ flood at Grieve Field. We have not yet recognized proved tertiary reserves in these fields.

Costs are transferred into the amortization base on an ongoing basis as projects are evaluated and proved reserves established or impairment determined. We review the excluded properties for impairment at least annually. We currently estimate that evaluation of the majority of these properties and the inclusion of their costs in the amortization base is expected to be completed within five to ten years. Until we are able to determine whether there are any proved reserves attributable to the above costs, we are not able to assess the future impact on the amortization rate of the full cost pool.