The company records the fair value of a liability for an asset retirement obligation (ARO) both as an asset and a liability when there is a legal obligation associated with the retirement of a tangible long-lived asset and the liability can be reasonably estimated. The legal obligation to perform the asset retirement activity is unconditional, even though uncertainty may exist about the timing and/or method of settlement that may be beyond the company’s control. This uncertainty about the timing and/or method of settlement is factored into the measurement of the liability when sufficient information exists to reasonably estimate fair value. The ARO liability is initially recognized at its fair value with an increase to the related asset. Subsequent accretion of the liability and depreciation of the asset is recorded over time. The company evaluates its ARO estimates regularly or when there is significant new information about costs, timing, and duration of asset retirement activity.

AROs are primarily recorded for the company’s crude oil and natural gas producing assets. No significant AROs associated with any legal obligations to retire downstream long-lived assets have been recognized, as indeterminate settlement dates for the asset retirements prevent estimation of the fair value of the associated ARO. The company performs periodic reviews of its downstream long-lived assets for any changes in facts and circumstances that might require recognition of a retirement obligation.


	2025		2024		2023
Balance at January 1	$	12,667	$	13,833	$	12,701

Liabilities assumed in acquisition	1,682		—		220
Liabilities incurred	186		83		183
Liabilities settled	(1,109)		(2,083)		(1,471)
Reduction due to asset sales	(458)		(171)		(94)
Accretion expense	617		588		593
Revisions in estimated cash flows	1,403		417		1,701
Balance at December 31	$	14,988	$	12,667	$	13,833

In the table above, the amount associated with “Revisions in estimated cash flows” primarily reflects increased cost estimates and scope changes to decommission wells, equipment and facilities. The long-term portion of the $14,988 balance at the end of 2025 was $13,919.