Prospectus re Admission to the Official List - Heritage Oil

Production assumptionsProduction during the projected period is only assumed to arise in respect of the Bukha and West Bukhafields in Oman, together with the Zapadno Chumpasskoye field in Russia. Production as set out below isconsistent with the assumptions stated in the RPS Report in Part III of this document.15 months ending 12 months ending 12 months ending31 December 2008 31 December 2009 31 December 2010Boepd Boepd BoepdOman:Bukha ................................. 126 — —West Bukha ............................. 375 1,560 1,878Russia:Zapadno Chumpasskoye .................... 1,110 2,198 4,275Production is expected to commence from the West Bukha field in the third quarter of 2008 with salescommencing in the same period. It is assumed that production from the Bukha field will cease when WestBukha commences production.The Directors have assumed that all the production licences are and will remain valid over the period ofthe Illustrative Projections.No additional production is assumed to arise from projects and activities which form part of the Group’slong-term strategic plans and intentions, but which are not reflected in the report prepared by RPS inPart III of this document. Production has only been included from projects which have proved andprobable reserves certified by RPS at 30 September 2007.Price assumptionsThe assumed weighted average selling prices for future oil, gas, condensate and LPG sales, set out below,are in accordance with the base case assumptions underlying the report prepared by RPS in Part III of thisdocument.15 months ending 12 months ending 12 months ending31 December 2008 31 December 2009 31 December 2010Oman:Condensate, $/bbl ......................... 84 85 87LPG, $/tonn ............................. 542 547 555Gas, $/mcf .............................. 1 1 1Russia:Crude oil, $/bbl .......................... 55 53 51Cost assumptionsAn overview of the operating and capital expenditures has been given below. These expenditures havebeen estimated in accordance with the long-term strategic plans of the Group at the date of this document,as reflected in the report prepared by RPS in Part III of this document.Operating costs15 months ending 12 months ending 12 months ending31 December 2008 31 December 2009 31 December 2010$ million $ million $ millionOman:Bukha ................................. 1.0 — —West Bukha ............................. 0.3 0.9 1.1Russia:Zapadno Chumpasskoye .................... 7.8 9.9 12.6241