surprise field size, page-4

They will try and use mass balance to determine the size of the reservoir that Surprise-1H is 'seeing' from the EPT.

But unless it is very small (ie a failure) I wouldn't expect it to be visible yet. They basically need to pump enough to deplete the reservoir a little bit before they can get an idea of volume.

It will also only work if the structure is not compartmentalised and the whole 100 MMbo is is one big structure.

The only conclusive result they'd get at this early stage was if the reservoir was too small and they were already starting to see depletion.

So all in all I don't expect they have much idea yet. When they do have an idea from MB they will be able to get reserves certified which they will hopefully release to the market.

If it's only, say, 1 MMbo it doesn't necessarily mean that's the whole structure, it just means that this one well can't access the whole structure. This is quite likely in tighter reservoirs where depositional and diagenetic changes, not to mention faulting, may easily have compartmentalised the reservoir.