This excerpt taken from the PBR 20-F filed Jun 30, 2005.
Our strong reserve base
As of December 31, 2004, we had estimated proved developed and undeveloped crude oil and natural gas reserves of approximately 11.82 billion barrels of oil equivalent in Brazil and abroad. In addition, we have a substantial base of exploration acreage both in Brazil and abroad, which we are exploring by ourselves and with industry partners in order to continue to increase our reserves.
As of December 31, 2004, our worldwide proved reserves to production ratio was 16.9 years.
The majority of our reserves, including recent discoveries, are located in deep-water areas that generally require additional planning, more comprehensive evaluation and added lead time to begin production when compared to onshore production. In accordance with our strategic plan for the period from 2004 to 2010, or Strategic Plan, we have been investing the necessary capital to build the offshore platforms needed to monetize these reserves. Although our proved reserve life is higher than the industry average, the additional planning required to bring deep-water areas into production also means that our percentage of proved undeveloped reserves may be higher than the industry average.
We believe that our proved reserves will provide us with significant opportunities for sustaining and increasing production growth.