Volumetric Reserves: 2021 #14

A true vertical depth well log (all depths ss) shows a structure top at 7,980 ft and an OWC about 8,140 ft. The log also shows three porosity intervals 35 ft, 30 ft, and 30 ft thick, with porosity interval tops at 8,020 ft, 8,070 ft, and 8,100 ft, each separated by shale breaks. A true statement regarding calculating volumetric reserves in the above situation is (select any that apply):

This type of problem tests your knowledge of P2 and P3 reserves, logging data, and general oilfield knowledge. In the end, there is no shortcut to understanding the basics of logging data. So if it's not something you work with often, get familar with the applicable SPE Handbook and SPE Textbook material. The Guidebook has a good summary as well.

Reserves: 2018 #65

Problem 65: When estimating primary oil and gas reserves, the LEAST accurate statement is: 

(A) Drive mechanism is more important than well spacing for recovery efficiency. 
(B) A gas deviation factor estimated using empirical correlations...is acceptably accurate...
(C) The differential rather than flash formation volume factor should be used.
(D) ...capillary-pressure method...OWC...must be a robust correlation between porosity & perm. 

This solution (C) is found in the Guidebook 13 RES 13. Keep in mind, this sort of question you just have to understand each part, and the CBT forces you to know it. So read the Guidebook notes and learn them for the exam.

Also, read about this subject in detail in the HS5 P1509, P1509, P1512, and P1606. P1512 has a long discussion of the need for flash FVF use, well worth your time.