Property, Plant and Equipment

Property, plant and equipment consists of the following (in thousands):



	December 31,
	2014			2013
Oil and natural gas properties
Proved(1)	$	11,707,147		$	10,972,816
Unproved	290,596			531,606
Total oil and natural gas properties	11,997,743			11,504,422
Less accumulated depreciation, depletion and impairment	(6,359,149		)	(5,762,969		)
Net oil and natural gas properties capitalized costs	5,638,594			5,741,453
Land	16,300			18,423
Non-oil and natural gas equipment(2)	602,392			600,603
Buildings and structures(3)	263,191			233,405
Total	881,883			852,431
Less accumulated depreciation and amortization	(305,420		)	(286,209		)
Other property, plant and equipment, net	576,463			566,222
Total property, plant and equipment, net	$	6,215,057		$	6,307,675

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(1)	Includes cumulative capitalized interest of approximately $38.1 million and $23.4 million at December 31, 2014 and 2013, respectively.


(2)	Includes cumulative capitalized interest of approximately $4.3 million at both December 31, 2014 and 2013.


(3)	Includes cumulative capitalized interest of approximately $17.1 million and $12.0 million at December 31, 2014 and 2013, respectively.

Accumulated depreciation, depletion and impairment for oil and natural gas properties includes cumulative full cost ceiling limitation impairment of $3.7 billion and $3.5 billion at December 31, 2014 and 2013, respectively. During the year ended December 31, 2014, the Company reduced the net carrying value of its oil and natural gas properties by $164.8 million as a result of its first quarter full cost ceiling analysis. There was no full cost ceiling impairment during the years ended December 31, 2013 or 2012. See Note 8 for discussion of impairment of other property, plant and equipment.

The average rates used for depreciation and depletion of oil and natural gas properties were $15.00 per Boe in 2014, $16.81 per Boe in 2013 and $16.93 per Boe in 2012.

Century Plant Construction Costs

Included in proved oil and natural gas properties at December 31, 2014 and 2013 is approximately $180.0 million of costs in excess of contracted and reimbursed amounts incurred by the Company during construction of the Century Plant pursuant to an agreement with Occidental Petroleum Corporation (“Occidental”). Due to the high-CO₂ content of the Company’s reserves in the Piñon Field and the absence of adequate processing capacity in the Piñon Field area, construction of a large-scale processing facility, such as the Century Plant, was necessary for the development of the Company’s natural gas reserves in that area. The Company entered into the construction agreement and a related treating agreement with Occidental solely to facilitate the development of its reserves in the Piñon Field and greater West Texas Overthrust area and, accordingly, has recorded these unreimbursed costs as development costs within its full cost pool. See Note 15 for discussion of the related treating agreement.

Drilling Carry Commitments

During the years ended December 31, 2014, 2013 and 2012, the Company was party to agreements with two co-working interest parties, which contain carry commitments to fund a portion of its future drilling, completing and equipping costs within areas of mutual interest. The Company recorded approximately $205.6 million for Repsol’s carry during the year ended December 31, 2014, and a combined $408.0 million and $367.6 million for both Atinum’s and Repsol’s drilling carries during the years ended December 31, 2013 and 2012, respectively, which reduced the Company’s capital expenditures for the respective periods. Atinum fully funded its carry commitment in the third quarter of 2013, and the carry commitment from Repsol was fully utilized during the third quarter of 2014.

Under the agreement with Repsol, the carry commitment could have been reduced if a certain number of wells were not drilled within the area of mutual interest during a 12-month period and the Company failed to drill such wells following a proposal by Repsol to drill the wells. During 2013, the Company temporarily reduced its rate of drilling activity. As a result, the Company drilled less than the targeted number of wells for such 12-month period, which resulted in Repsol having a right to propose additional wells. In the second quarter of 2014, the Company and Repsol amended their agreement to eliminate Repsol’s right to propose such additional wells in exchange for a commitment by the Company to drill 484 net wells in the area of mutual interest between January 1, 2014 and May 31, 2015, subject to delays due to factors beyond the Company’s control. If the Company does not drill the committed number of wells within such time period, it will be required to carry Repsol’s drilling, completing and equipping costs for subsequent wells drilled in the area of mutual interest, up to a maximum of $75.0 million in carry costs. As of December 31, 2014, the Company has drilled 340 net wells under this arrangement and currently anticipates satisfying its drilling commitment within the required time period. Other than the above, the Company has no drilling obligations to Repsol.

Costs Excluded from Amortization

The following table summarizes the costs, by year incurred, related to unproved properties and pipe inventory, which were excluded from oil and natural gas properties subject to amortization at December 31, 2014 (in thousands):



			Year Cost Incurred
	Total		2014		2013		2012		2011 and Prior
Property acquisition	$	247,485	$	64,776	$	21,723	$	98,530	$	62,456
Exploration(1)	96,752		48,614		36,938		4,302		6,898
Total costs incurred	$	344,237	$	113,390	$	58,661	$	102,832	$	69,354

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(1)	Includes $53.6 million of pipe inventory costs incurred ($21.3 million in 2014, $30.7 million in 2013 and $1.6 million in 2012 and prior years).

The Company expects to complete the majority of the evaluation activities within 10 years from the applicable date of acquisition, contingent on the Company’s capital expenditures and drilling program. In addition, the Company’s internal engineers evaluate all properties on at least an annual basis.