Capitalized Exploratory Well Costs (Tables)

12 Months Ended

Dec. 31, 2015

Capitalized Exploratory Well Costs [Abstract]

Changes in Capitalized Exploratory Well Costs

Changes in capitalized exploratory well costs are as follows and exclude amounts that were capitalized and subsequently expensed in the same period:



	Year Ended December 31,
(millions)	2015			2014			2013
Capitalized Exploratory Well Costs, Beginning of Period	$	1,337		$	1,301		$	900
Additions to Capitalized Exploratory Well Costs Pending Determination of Proved Reserves	123			316			581
Reclassified to Proved Oil and Gas Properties Based on Determination of Proved Reserves or to Assets Held for Sale⁽¹⁾	(19		)	(196		)	(177		)
Capitalized Exploratory Well Costs Charged to Expense ⁽²⁾	(88		)	(84		)	(3		)
Capitalized Exploratory Well Costs, End of Period	$	1,353		$	1,337		$	1,301

⁽¹⁾ The 2015 amount relates primarily to onshore US exploration activity.

The 2014 amount relates primarily to the Dantzler well (deepwater Gulf of Mexico), for which we sanctioned a development plan, and the Karish and Tanin wells (offshore Israel), which were reclassified to assets held for sale.

The 2013 amount relates primarily to Gunflint (deepwater Gulf of Mexico), for which we sanctioned a development plan.

⁽²⁾ The 2015 amount relates primarily to northeast Nevada. After assessing its commercial viability in the current commodity price environment, we elected to discontinue our exploration efforts.

The 2014 amount relates to non-core onshore US exploratory well costs and the Scotia exploratory well (offshore Falkland Islands) which were determined to be non-commercial.

Aging of Capitalized Well Costs

The following table provides an aging of capitalized exploratory well costs based on the date that drilling commenced, and the number of projects that have been capitalized for a period greater than one year:



	December 31,
(millions)	2015		2014		2013
Exploratory Well Costs Capitalized for a Period of One Year or Less	$	95	$	247	$	568
Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling	1,258		1,090		733
Balance at End of Period	$	1,353	$	1,337	$	1,301
Number of Projects with Exploratory Well Costs That Have Been Capitalized for a Period Greater Than One Year Since Commencement of Drilling	14		13		13

Aging of Exploratory Well Costs

The following table provides a further aging of those exploratory well costs that have been capitalized for a period greater than one year since the commencement of drilling as of December 31, 2015:



		Suspended Since
Country/Project (millions)	Total	2013 - 2014	2011 - 2012	2010 & Prior	Progress
Deepwater Gulf of Mexico
Troubadour	49	48	1	—	Evaluating development scenarios for this 2013 natural gas discovery including subsea tieback to existing infrastructure.
Katmai	91	91	—	—	Anticipate drilling an appraisal well in 2016 to test the resource potential of this 2014 crude oil discovery.
Offshore Equatorial Guinea
Diega (Block O) and Carmen (Block I)	233	135	45	53	Evaluating regional development scenarios for this 2008 crude oil discovery. We drilled subsequent appraisal wells. During 2014, we conducted additional seismic activity over Blocks O and I and are engaged in processing the newly-acquired seismic data.
Carla (Block O)	177	133	44	—	Evaluating regional development scenarios for this 2011 crude oil discovery. We drilled subsequent appraisal wells. During 2014, we conducted additional seismic activity over Blocks O and I and are engaged in processing the newly-acquired seismic data.



Yolanda/Felicita	66		18		4		44		Evaluating regional development plans for these 2007/2008 condensate and natural gas discoveries. Natural gas development teams are working with the governments of Equatorial Guinea and Cameroon to evaluate natural gas monetization options and finalize data exchange agreements between the two countries.
Offshore Cameroon
YoYo	51		6		11		34		Working with the government to assess commercialization of this 2007 condensate and natural gas discovery. A natural gas development team is working with the governments of Equatorial Guinea and Cameroon to evaluate natural gas monetization options and finalize a data exchange agreement between the two countries.
Offshore Israel
Leviathan	191		44		106		41		During 2015, the Government of Israel approved the Natural Gas Framework. We are engaged in natural gas marketing activities both for export and, since the enactment of the Natural Gas Framework, for domestic Israeli customers. We continue to refine our development concepts and are preparing to submit a Plan of Development to the Government of Israel. We also continue to pursue financing arrangements to support development.
Leviathan-1 Deep	80		7		73		—		Well did not reach the target interval; developing future drilling plans to test this deep oil concept, which is held by the Leviathan Development and Production Leases. We are working on potential well design and placement.
Dalit	28		5		3		20		Submitted a development plan to the government to develop this 2009 natural gas discovery as a tie-in to existing infrastructure.
Dolphin 1	26		3		23		—		Reviewing regional development scenarios for this 2011 natural gas discovery, including a potential tieback to Leviathan. We have applied to the government for a commerciality ruling.
Offshore Cyprus
Cyprus	214		140		74		—		During 2015, we submitted a Declaration of Commerciality and a Development Plan to the Government of Cyprus. We continue to work with the Government of Cyprus to obtain approval of the development plan and the subsequent issuance of an Exploitation License. Receiving an Exploitation License will allow us and our partners to perform the necessary engineering and design studies and progress the project to final investment decision.
Other
Projects less than $20 million	52		41		—		11		Continuing to drill and evaluate wells
Total	$	1,258	$	671	$	384	$	203