NOTES TO THE CONSOLIDATED FINANCIAL STATEMENTS  NOTE 17 – IMPAIRMENT OF NON-CURRENT ASSETS  The impairment charge of $71.2 million noted above is primarily the result from the lower oil price environment.  (1) Carrying costs exclude work-in-progress that is not subject to impairment analysis.  At 31 December 2014, the Group reassessed the carrying amount of its non-current assets for indicators of  impairment in accordance with the Group’s accounting policy. Due to the change in the oil pricing environment at  year-end, the Company determined that there was an indication of impairment for development and production  assets.  Each of the Group’s development and production asset CGUs include all of its developed producing properties,  shared infrastructure supporting its production and undeveloped acreage that the Group considers technically  feasible and commercially viable.  Estimates of recoverable amounts are based on the higher of an asset’s value-in-use or fair value less costs to sell  (level 3 fair value hierarchy), using a discounted cash flow method, and are most sensitive to the key assumptions  such as pricing, discount rates, and reserve risk factors. The Group has used the FVLCS calculation whereby future  cash flows are based on estimates of hydrocarbon reserves in addition to other relevant factors such as value  attributable to additional reserves based on production plans.  Estimates of future commodity prices are based on the Group’s best estimates of future market prices with reference  to external market analysts’ forecasts, current spot prices and forward curves. At 31 December 2014, future NYMEX  strip prices, adjusted for basis differentials, were applied in 2015 and gradually increased through 2016 to $75/bbl  in 2017 and thereafter. The post-tax discount rate that has been applied to the above non-current assets was 8.0%. The Group also applied  further risk-adjustments appropriate for risks associated with its developed and undeveloped reserves using a  weighted average risk-adjustment rate of 6% and 17%, respectively, based on the risk associate with each reserve  category.  Recoverable amounts and resulting impairment write-downs recognized in the Consolidated Statements of Profit or  Loss and Other Comprehensive Income for the year ended 31 December 2014 are presented in the table below:  Carrying costs (1)  Recoverable  amount  Impairment  Cash-generating unit  US$’000  US$’000  US$’000  Development and production assets: Eagle Ford 400,761  389,764  10,997  Mississippian/Woodford  125,535  65,320  60,215  Total development and production assets  526,296  455,084  71,212  - 84 - 