Oil and Natural Gas Properties

6 Months Ended

Jun. 30, 2016

Property, Plant and Equipment [Abstract]

Oil and Natural Gas Properties

OIL AND NATURAL GAS PROPERTIES

Full cost accounting rules require us to review the carrying value of our oil and natural gas properties at the end of each quarter. Under those rules, the maximum amount allowed as the carrying value is referred to as the ceiling. The ceiling is the sum of the present value (using a 10% discount rate) of the estimated future net revenues from our proved reserves (using the unescalated 12-month average price of our oil, NGLs, and natural gas), plus the cost of properties not being amortized, plus the lower of cost or estimated fair value of unproved properties included in the costs being amortized, less related income taxes. If the net book value of the oil, NGLs, and natural gas properties being amortized exceeds the full cost ceiling, the excess amount is charged to expense in the period during which the excess occurs, even if prices are depressed for only a short while. Once incurred, a write-down of oil and natural gas properties is not reversible.

During the first quarter of 2015, the 12-month average commodity prices decreased significantly, resulting in a non-cash ceiling test write-down of $400.6 million pre-tax ($249.4 million, net of tax). During the second quarter of 2015, the 12-month average commodity prices decreased further, resulting in a non-cash ceiling test write-down of $410.5 million pre-tax ($255.6 million, net of tax).

During the first quarter of 2016, the 12-month average commodity prices continued to decrease, resulting in a non-cash ceiling test write-down of $37.8 million pre-tax ($23.5 million, net of tax). For the second quarter of 2016, the 12-month average commodity prices decreased further, resulting in a non-cash ceiling test write-down of $74.3 million pre-tax ($46.3 million, net of tax).