recognise value, page-5

It is certainly a technical term and there was a lot of discussion about this sort of issue on the GGP/VIL sites back about January when the Fausse Point -1 well was being drilled and certain levels produced gas shows.

I do not claim to have a complete detailed answer to your question but in simple terms (or at least as I understand it) it is a measure of the gas level in the drilling mud.

Now a measure of over 4,000 units is indicating a pretty strong gas presence. Even 2,000 odd is fairly good.

However, while it is a very positive sign, it is not a guarantee that there is gas in commercial quantities there.
It may simply be a small pocket of gas under high pressure that is released as the well strikes into that zone.

So at this stage it is encouraging and is probably a very good sign since it occurred at the right depth, but it is not conclusive.
That is what the wireline logging and other tests are for.

(NOTE: I hold GGPO)