A statistical analysis of China's large oilfields(OIP

>

1?10

8

t) is made in respect of the scales

locations

abundance

and crude quality of the geologic and recoverable reserves as well as the production

and reserve-production ratio of these oilfields in 2004.A comparison with the corresponding statistics in 1984 shows that the geologic and recoverable oil reserves of the large and giant oilfields in east china increased by 2.1 and 1.6 times respectively

while those in west China increased by 4.8 and 3.6 times respectively.Six offshore oilfields reached the lower limit of large fields.In 2004

the reserves and production rate of the large and giant oilfields in east China still remained the highest among all the oilfields in the country.Light and medium crude oil accounted for 68.2% of the recoverable oil reserves of these oilfields

while heavy oil dominated the large and giant offshore oilfields.Past experiences indicate that more large and giant oilfields will be discovered and developed in each oil region of China

but the crude quality will be on the downgrade.