2010 Santos Reserves Report

Santos increases 2P reserves to 1,445 million barrels

Santos today announced that proved and probable (2P) hydrocarbon reserves increased to 1,445
million barrels of oil equivalent (mmboe) as at the end of 2010. This represents a 2P reserves
replacement ratio of 110% and is the company’s seventh successive annual increase in its
Successful exploration, appraisal and commercialisation activity, along with the sanctioning of new
projects, added 165 mmboe of 2P reserves in 2010
The increase in reserves was driven by strong growth in coal seam gas (CSG) reserves dedicated
to the GLNG project. Reserves also increased in the Cooper Basin and through the sanctioning of
the Spar (Western Australia) and Wortel (Indonesia) gas projects.
After the sale of a 15% interest in GLNG to Total for $650 million announced in September
(approximately 110 mmboe) and 2010 production of 50 mmboe, Santos’ year-end 2P reserves
increased to 1,445 mmboe.