The company continues to capitalize exploratory well costs after the completion of drilling when the well has found a sufficient quantity of reserves to justify completion as a producing well, and the business unit is making sufficient progress assessing the reserves and the economic and operating viability of the project. If either condition is not met or if the company obtains information that raises substantial doubt about the economic or operational viability of the project, the exploratory well would be assumed to be impaired, and its costs, net of any salvage value, would be charged to expense.

The following table indicates the changes to the company’s suspended exploratory well costs for the three years ended December 31, 2025:


	2025		2024		2023
Beginning balance at January 1	$	1,662	$	1,648	$	1,627
Additions to capitalized exploratory well costs pending the determination of proved reserves	150		14		88
Reclassifications to wells, facilities and equipment based on the determination of proved reserves	—		—		—
Capitalized exploratory well costs charged to expense	(1)		—		(67)
Other reductions*	(52)		—		—
Ending balance at December 31	$	1,759	$	1,662	$	1,648

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
	2025		2024		2023
Exploratory well costs capitalized for a period of one year or less	$	148	$	17	$	78
Exploratory well costs capitalized for a period greater than one year	1,611		1,645		1,570
Balance at December 31	$	1,759	$	1,662	$	1,648
Number of projects with exploratory well costs that have been capitalized for a period greater than one year*	15		14		13

Of the $1,611 of exploratory well costs capitalized for more than one year at December 31, 2025, $848 is related to nine projects that had drilling activities underway or firmly planned for the near future. The $763 balance is related to six projects in areas requiring a major capital expenditure before production could begin and for which additional drilling efforts were not underway or firmly planned for the near future. Additional drilling was not deemed necessary because the presence of hydrocarbons had already been established, and other activities were in process to enable a future decision on project development.

The projects for the $763 referenced above had the following activities associated with assessing the reserves and the projects’ economic viability: (a) $348 (four projects) – undergoing front-end engineering and design with final investment decision expected within four years; (b) $415 (two projects) – development alternatives under review. While progress was being made on all 15 projects, the decision on the recognition of proved reserves under SEC rules in some cases may not occur for several years because of the complexity, scale and negotiations associated with the projects. More than half of these decisions are expected to occur in the next five years.

The $1,611 of suspended well costs capitalized for a period greater than one year as of December 31, 2025, represents 73 exploratory wells in 15 projects. 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
2000-2009	$	263	14
2010-2014	1,068		46
2015-2024	280		13
Total	$	1,611	73

Aging based on drilling completion date of last suspended well in project:	Amount		Number of projects
2008-2012	$	292	2
2013-2016	1,030		6
2017-2025	289		7
Total	$	1,611	15