Asset Retirement Obligations and Accrued Environmental Costs (Tables)

12 Months Ended

Dec. 31, 2021

Asset Retirement Obligations and Accrued Environmental Costs [Abstract]

Asset Retirement Obligations and Accrued Environmental Costs

Asset retirement obligations and accrued environmental costs at December 31 were:

Millions of Dollars

2021

2020

Asset retirement obligations

$

5,926

5,573

Accrued environmental costs

187

180

Total asset retirement obligations and accrued environmental costs

6,113

5,753

Asset retirement obligations and accrued environmental costs due within one year*

(359)

(323)

Long-term asset retirement obligations and accrued environmental costs

$

5,754

5,430

*Classified as a current liability on the balance sheet under “Other accruals.”

Changes in Asset Retirement Obligation

During 2021 and 2020, our overall ARO changed as follows:

Millions of Dollars

2021

2020

Balance at January 1

$

5,573

6,206

Accretion of discount

238

248

New obligations

555

262

Changes in estimates of existing obligations

(113)

(307)

Spending on existing obligations

(164)

(116)

Property dispositions

(108)

(771)

Foreign currency translation

(55)

51

Balance at December 31

$

5,926

5,573