Inventories

12 Months Ended

Dec. 31, 2018

Inventories are stated at the lower of cost and net realizable value. In the United States, we manufacture certain finished products and parts inventories for drill bits, completion products, bulk materials and other tools that are recorded using the last-in, first-out method, which totaled $186 million at December 31, 2018 and $177 million at December 31, 2017. If the average cost method had been used, total inventories would have been $24 million higher than reported as of December 31, 2018 and $31 million higher as of December 31, 2017. The cost of the remaining inventory was recorded using the average cost method. Inventories consisted of the following:



	December 31
Millions of dollars	2018		2017
Finished products and parts	$	1,947	$	1,547
Raw materials and supplies	934		703
Work in process	147		146
Total	$	3,028	$	2,396

All amounts in the table above are reported net of obsolescence reserves of $219 million at December 31, 2018 and $276 million at December 31, 2017.