Approximately 29 per cent of ARC’s current P+P reserves are crude oil, five per cent are natural gas  liquids and 66 per cent are natural gas on a 6:1 conversion basis. As ARC develops its Montney assets in  northeast British Columbia, the natural gas component will increase. ARC’s crude oil, natural gas and natural gas liquids reserves were evaluated using gLJ Petroleum  Consultants Ltd’s (“gLJ”) product price forecasts effective January 1, 2011 prior to provision for interest,  debt service charges and general and administrative expenses. It should not be assumed that the nPv  estimated by gLJ represents the fair market value of the reserves. 24 10 ARC ResouRCes AnnuAl  report npv oF CAsh FloW beFoRe InCoMe tAXes usInG GlJ JAnu ARY 1, 2011 FoReCAst pRICes AnD Costs  (1 ) npV of cAsH floW Before  incoMe tAXes (1)  discounted discounted discounted discounted $Millions undiscounted  At 5%  At 10%  At 15%  At 20% Proved Producing  7,690  5,084  3,839  3,116  2,643 Proved Developed non-Producing  452  292  215  170  141 Proved Undeveloped  2,305  1,365  866  569  378 Total Proved  10,446  6,740  4,919  3,855  3,162 Probable 5,475 2,499 1,430 931 656 Proved plus Probable  15,921  9,240  6,350  4,786  3,818 (1) Additional information on reserves is available in the Annual information form and in the february 10, 2011 news release titled “Arc  resources ltd. 2010 year-end reserves increase by 29 per cent”. nET PRESEnT vALUE (“nPv”) SUMMARY RESERvE LIFE InDEX (“RLI”) reserVe life indeX  2010 (1) 2009 2008 2007 2006 Total Proved  10.4  10.3  10.4  9.8  9.8 Proved Plus Probable  15.2  14.5  13.8  12.5  12.4 ARC’s P+P RLI was 15.2 years at year-end 2010 while the proved RLI was 10.4 years based upon the gLJ  reserves and ARC’s 2011 production guidance mid-point of 85,500 boe per day. The increase in the P+P  RLI from 2008 through 2010 is attributed to the successful development of the Montney region and the  resultant increase in P+P reserves. The following table summarizes ARC’s historical RLI. (1) excludes 10.7 mmboe proved and 14.2 mmboe proved plus probable reserves relating to assets divested in January 2011 and included  in the year-end 2010 reserves evaluation. the 2011 production guidance of 85,500 boe per day excluded production from the divested  assets of approximately 3,400 boe per day. LIgHT/MED OIL HEAvY OIL ngLS nATURAL gAS 28% 1% 5% 66% PROvED PLUS PROBABLE COMPAnY InTEREST RESERvES BY COMMODITY TOTAL PROvED PROvED PLUS PROBABLE 16 14 12 10 8 6 4 2 0 RESERvE LIFE InDEX 06 07 08 09 10