| Note 5—Inventories | ||||
| Inventories at December 31 were: | ||||
| Millions of Dollars | ||||
| 2013 | 2012 | |||
| Crude oil and natural gas | $ | 452 | 244 | |
| Materials, supplies and other | 742 | 721 | ||
| $ | 1,194 | 965 | ||
Inventories valued on the LIFO basis totaled $343 million and $147 million at December 31, 2013 and 2012, respectively. The estimated excess of current replacement cost over LIFO cost of inventories was approximately $160 million at December 31, 2013, and $200 million at December 31, 2012. In 2013, there were no liquidations of LIFO inventory values impacting net income from continuing operations.