abandon the facility has been made, as the indeterminate settlement dates for the asset retirements prevent estimation of the fair value of the asset retirement obligation.

Refer to the discussion below for additional information on environmental matters and their impact on Chevron, and on the company's 2017 environmental expenditures. Refer to Note 25 on page 88 for additional discussion of environmental remediation provisions and year-end reserves. Refer also to Note 26 on page 89 for additional discussion of the company's asset retirement obligations.

Suspended Wells Information related to suspended wells is included in Note 21, Accounting for Suspended Exploratory Wells, beginning on page 80.

Income Taxes Information related to income tax contingencies is included on pages 75 through 78 in Note 18 and page 87 in Note 25 under the heading “Income Taxes.”

Other Contingencies Information related to other contingencies is included on page 89 in Note 25 to the Consolidated Financial Statements under the heading “Other Contingencies.”