reserves

Did anyone else have a close look at the reserves table in the PSA Annual Report?

There are some big differences between the "official" proved & probable figures from Ryder Scott and Petsec's own estimates - eg for the most recent Vermilion well the proved and probable figure is 2.4 bcf but PSA's figure is 9 bcf. With US gas worth around $8 million (aussie) ber bcf that's a difference of more than $50 million or over $0.40 per share on one well alone.

It would be nice to think that the Ryder Scott numbers are very conservative and Petsec's figures are what's really likely to be there, but the same table shows that in 2003 Petsec's initial reserve figure was slashed by about 50% due to "reserve revisions".

Does anyone out there have any insights into this?