Property, Plant, and Equipment (Tables)

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property, plant, and equipment

Property, plant, and equipment were composed of the following:

	December 31
Millions of dollars	2021		2020
Land	$	120	$	120
Buildings and property improvements	1,608		1,652
Machinery, equipment, and other	14,040		13,592
Total	15,768		15,364
Less accumulated depreciation	11,442		11,039
Net property, plant, and equipment	$	4,326	$	4,325

Percentages of building and property improvements, and total machinery, and equipment and other, excluding oil and natural gas investments, depreciated over useful lives

Classes of assets are depreciated over the following useful lives:

	Buildings and Property Improvements
	2021	2020
1    -   10 years	17%	13%
11    -   20 years	39%	41%
21    -   30 years	24%	21%
31    -   40 years	20%	25%

	Machinery, Equipment, and Other
	2021	2020
1    -    5 years	49%	49%
6    -   10 years	41%	41%
11    -   20 years	10%	10%