This excerpt taken from the CHK 8-K filed Nov 1, 2005.
Fixed assets are carried at cost. Depreciation is calculated using the straight-line method based on estimated service lives, ranging from 5 to 30 years, except for oil and gas production properties as explained below. The depreciable life for general plant ranges from 5 to 30 years and for gathering assets from 20 to 30 years. The cost of minor repairs and replacements is charged to maintenance expense as incurred.
Columbia Energy Resources, LLC (a wholly owned
subsidiary of Triana Energy Holdings, LLC)
Notes to Consolidated Financial Statements (continued)
2. Critical Accounting Policies and Estimates (continued)