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.
Hi David, can you please explain the answer to the question 24 for 2018 PE problems ?
ReplyDeleteWhy B is not correct? From 7 PRD 11, the rod stroke length S can be found from the card.
Thanks for your help!
Problem 24. The LEAST true statement about rod pump dynamometer cards is:
ReplyDelete(A) A surface card (load versus position) can be used to find surface system torque.
(B) A pump card (load versus position) can be used to find polished rod stroke length.
(C) A pump card (load versus position) can be used to find the fluid weight on the pump.
(D) A surface card (load versus position) can used to find minimum and peak polished rod load.
If you look at 7 PRD 11, you can see the two card types - surface at top, pump at bottom. "S" is the polished rod stroke length which is found from the top one (surface), and Sp is the bottom stroke, not the polished rod. Does this check out?
The guidebook says "the differential rather than flash formation volume factor should be used." How is that one the least accurate?
ReplyDeleteWhat GB version do you have? The 2018 #3 version I'm looking at has "the flash rather than the differential FVF should be used". You may have an older version that has a typo that has been since fixed; let me know what your version is. If this is so, just pencil the correction in. I make a point to create problems from older GB pages that had typos so they all get caught by the user even if they are using an older version.
Delete