Now you are talking about the obtainability of the reserves, which is a different subject. Proving that reserves exist is done entirely by probing using a number of methods. Nobody randomly drills 5km into the ground to prove the existence of reserves.
That is why exxonExxon is asking for 25% ... Do you know how many wildcats hit dry or >90% watercuts? Over 80% in unexplored regions. Out of the 20% that do encounter hydrocarbons only a small percentage hit significant "pools". Oil&Gas exploration is a very risky endeavour.
The risk is very high for E&P companies and to obtain financial capital from investment firms is very hard for these companies.
I have never heard of the term "probing for reserves". Reserves are not exploratory plays.
Now you are talking about the obtainability of the reserves, which is a different subject. Proving that reserves exist is done entirely by probing using a number of methods. Nobody randomly drills 5km into the ground to prove the existence of reserves.
There is no such thing as "obtainabity of reserves". Reserves are only established once you have drilled your well and established reserves.
Geological surveys only speak about probability of finding hydrocarbons.... Not about reserves estimation.
1. Volumeteic reserves are established once you have an understanding of the porosity, saturations, and net pay maps.
2. Material balance reserves are established with fluid properties and the different drive mechanism.
3. Production reserves are based on production data of at least 6 months beyond the initial high GOR production to get decline analysis.
You combine 1,2 and 3 to get a good number on Reserves.
