Accounting for Suspended Exploratory Wells (Tables)

12 Months Ended

Dec. 31, 2013

Accounting for Suspended Exploratory Wells [Abstract]

Changes in company's suspended exploratory well costs

The following table indicates the changes to the company’s suspended exploratory well costs for the three years ended December 31, 2013:

	2013			2012			2011
Beginning balance at January 1	$	2,681		$	2,434		$	2,718
Additions to capitalized exploratory well costs pending the determination of proved reserves	885			595			652
Reclassifications to wells, facilities and equipment based on the determination of proved reserves	(290		)	(244		)	(828		)
Capitalized exploratory well costs charged to expense	(31		)	(49		)	(45		)
Other reductions*	—			(55		)	(63		)
Ending balance at December 31	$	3,245		$	2,681		$	2,434

 * Represents property sales.

Aging of capitalized well costs and number of project

The following table provides an aging of capitalized well costs and the number of projects for which exploratory well costs have been capitalized for a period greater than one year since the completion of drilling.

	At December 31
	2013		2012		2011
Exploratory well costs capitalized for a period of one year or less	$	641	$	501	$	557
Exploratory well costs capitalized for a period greater than one year	2,604		2,180		1,877
Balance at December 31	$	3,245	$	2,681	$	2,434
Number of projects with exploratory well costs that have been capitalized for a period greater than one year*	51		46		47

* Certain projects have multiple wells or fields or both.

Aging of Costs on Well and Project Basis

The tables below contain the aging of these costs on a well and project basis:

Aging based on drilling completion date of individual wells:	Amount		Number of wells
1997–2002	$	120	28
2003–2007	531		46
2008–2012	1,953		117
Total	$	2,604	191
Aging based on drilling completion date of last suspended well in project:	Amount		Number of projects
1999	$	8	1
2003–2008	347		10
2009–2013	2,249		40
Total	$	2,604	51