Gas Reservoirs: 2021 #19

A gas reservoir produced 1 MMscf gas and 13 MSTB water. The current and initial gas formation value factors...reservoir modeling predicts two equally possible scenarios for water influx...The initial gas in place (MMscf) is most likely closest to: A) 27.1 B) 30.1 C) 33.1 D) There is likely not any water influx. 

This problem is fairly simple; just watch the units. It try to crank these out quickly and let the chips fall where they may, so it wouldn't surprise me if I had an error floating around on this one. Just remember on gas reservoir problems, 90% of the errors are units, and the last 10% are just misreading the problem.

Anyway, I'm posting #19 to address any questions, or even to take suggestions on how it could be modified to better prepare one for gas reservoir problems.

Klinkenburg: 2021 #18

This is a fairly tough word problem, and it shows how difficult reasonable questions can be when mixed in with so many different subjects on an 8 hour exam. To properly prepare one would have to read hundreds of pages out of the Handbook Series, have a very good memory, and then hope for the best. 

This problem, in contrast, culls any direct SPE quotes that could "reasonably" be asked on the subject. So: simply read this problem set and thus get a basic understanding and be fully armed with little effort. 

Make a point to avoid getting bogged down on the details, details that simply cannot be reasonably asked on this type of exam.

Resource Question

Question: I found your blog, thank you for all the information and practice questions and guide work. I am overwhelmed so far in my quest to study for the exam. Seeing your suggestions that I read SPE Textbook Series #1, #2, #12, and #4 and the 7 volume Petroleum Engineering books makes me think I need to start with a prep course to hone in on how to study efficiently. Based on commenters or private correspondence do you know which prep course is best suited for the newer CBT test?

Answer: I would merely 1) do as many practice problems as possible using the SPE Exam Resource. Once you've done that, you will have a solid idea of your weak areas and what resources you need to get. Only then would I consider taking a course as needed. Regarding which course, I think that depends on your specific weak areas. But since you will need to do practice problems anyway, start there.

Core Testing: 2021 #17

Effective liquid permeability is found in the lab by graphing gas permeability versus the reciprocal mean flowing pressure and extrapolating the reciprocal mean pressure to zero. In this problem, a rock core filled with gas “A” has a permeability of 40 md with an average flowing pressure of 1.25 atm and has a permeability of 30 md when said mean flowing pressure is doubled. If this same rock core is filled with gas “B” and then has a permeability of 40 md with a flowing pressure of 2.5 atm, the permeability (md) for gas “B” at a flowing pressure of 5 atm is closest to: A) 30 B) 25 C) 20 D) 15.

kg=30 md, “A”.
(GB 12 WLT 1; HS5 P994-995).