PROVEN PLUS PROBABLE RESERVES (SANTOS SHARE) BY ACTIVITY RESERVES (SANTOS SHARE)  (mmboe) (mmboe) PROVEN PLUS PROBABLE RESERVES (SANTOS SHARE) YEAR END 2004 BY  AREA  DEFINING RESERVES Santos has in place an evaluation and reporting process that is in line with international industry practice and is in general conformity with reserves definitions and resource classification systems published by the Society of Petroleum Engineers (SPE), World Petroleum Congress (WPC) and the American Association of Petroleum Geologists (AAPG). The definitions used are consistent with the requirements of the Australian Stock Exchange Ltd (ASX). Reserves are defined as those quantities of petroleum which are anticipated to be commercially recovered from known accumulations from a given date forward. Santos reports reserves net of the gas required for processing and transportation to the customer. Reserves reported are based on, and accurately reflect, information compiled by full-time employees of the Company who have the requisite qualifications and experience prescribed by the ASX Listing Rules. Santos’ reserves processes and procedures were reviewed by independent expert, Gaffney, Cline & Associates, and found to be ‘appropriate to providing robust estimates of Santos’ reserve position in accordance with international industry practice’. * Contingent resources excludes any contribution from Jeruk which was still under evaluation at year end. Sales gas  Crude oil Condensate LPG Total (incl. ethane) mmbbl mmbbl 000 mmboe PJ tonnes Reserves year end 2003 2,670  102  48  3,605  636  Production -190 -10 -3 -159 -47 Additions 157 1 0 24 29 Acquisitions/Divestments 110 2 1 98 22 Revisions 126 -21 3 -45 3 Estimated reserves year end 2004 2,873  74  49  3,523  643  Area Sales gas  Crude oil Condensate LPG Total (incl. ethane) mmbbl mmbbl 000 mmboe PJ tonnes Cooper Basin 1,051 24 15 1,842 233 Onshore Northern Territory 147 1 1 0 27 Offshore Northern Territory 310 1 27 1,507 92 Eastern Queensland 256 0 0 22 45 Southern Australia 271 0 2 152 50 Carnarvon Australia 555 43 3 0 141 PNG 0 1 0 0 1 Indonesia 243 4 0 0 46 USA 40 0 1 0 8 Total 2,873 74 49 3,523 643 Year en d Production Revisions Additions Acq/Divest Year end 2003 2004 Proven (1P) 338 -47 26 19  12  348  Proven plus Probable (2P) 636 -47 3  29  22  643  Contingent Resources (Best Estimate) 1,450 -  -4 -13 10  1,443* Annual Report 2004 25 EXTERNALLY REVIEWED  BOOKING PROCESS