Presented below are excerpts from the 2012 annual report of Royal Dutch Shell, a Dutch company that finds, extracts, processes, and sells oil and gas.
B—Depreciation, Depletion and Amortisation
Property, plant and equipment related to hydrocarbon production activities are depreciated on a unit-of-production basis over the proved developed reserves of the field concerned, except in the case of assets whose useful lives differ from the lifetime of the field, in which cases the straight-line method is applied. Rights and concessions in respect of proved properties are depleted on the unit-of-production basis over the total proved reserves of the relevant area. Where individually insignificant, unproved properties may be grouped and depreciated based on factors such as the average concession term and past experience of recognising proved reserves.(.)

Required:
Using the Royal Dutch Shell excerpts, identify the similarities and differences between U.S. GAAP and IFRS regarding accounting for property, plant, and equipment.