In a statement to the media, Sinopec Chairman Chen Tonghai, revealed that re-categorisation was the result of guidelines used by the company.

“In accordance with the evaluation guideline used by the company, those undeveloped reserves of crude oil and natural gas over three years were re-categorised. For these reasons, the newly added proved reserves of crude oil and natural in 2003 declined,” said Chen.

As a result of the re-categorisation, Sinopec proven oil and gas reserves now stand at 3.74 billion barrels of oil equivalent in 2003 – a fall of 3.54% year-on-year. Newly added proven reserves have also fallen to around 208 million barrels in 2003 – a fall of 45%.

The Xihu Trough, located in the East China Sea, is a massive project being undertaken by Sinopec (30% stake), CNOOC Ltd (30%), Royal Dutch/Shell (20%) and Unocal Corp (20%).