Capitalized Exploratory Well Costs and Undeveloped Leasehold Costs

3 Months Ended

Mar. 31, 2020

Capitalized Exploratory Well Costs and Undeveloped Leasehold Costs

Note 6. Capitalized Exploratory Well Costs and Undeveloped Leasehold Costs

Capitalized Exploratory Well Costs There were no significant changes to our capitalized exploratory well costs during the period. The following table provides an aging of capitalized exploratory well costs based on the date that drilling commenced:



(millions, except number of projects)	March 31, 2020		December 31, 2019
Exploratory Well Costs Capitalized for a Period of One Year or Less	$	30	$	22
Exploratory Well Costs Capitalized for a Period Greater Than One Year Since Commencement of Drilling	261		258
Capitalized Exploratory Well Costs, End of Period	$	291	$	280
Number of Projects with Exploratory Well Costs That Have Been Capitalized for a Period Greater Than One Year Since Commencement of Drilling	5		5

Undeveloped Leasehold Costs Changes in undeveloped leasehold costs are as follows:



(millions)	Three Months Ended March 31, 2020
Undeveloped Leasehold Costs, Beginning of Period	$	2,152
Additions to Undeveloped Leasehold Costs	2
Impairment ⁽¹⁾	(1,485		)
Other	(2		)
Undeveloped Leasehold Costs, End of Period	$	667


⁽¹⁾	Relates to impairments of undeveloped leasehold costs for unproved properties in the Delaware Basin and Eagle Ford Shale. See Note 2. Basis of Presentation and Note 4. Impairments.

As of March 31, 2020, undeveloped leasehold costs included $530 million, $80 million, and $57 million attributable to the Delaware Basin, other US onshore properties and international properties, respectively. Certain of these costs pertain to acquired leases or licenses that are subject to expiration over the next several years unless production is established on the acreage, while other costs pertain to acreage that is being held by production.