24-Pet-B3 Petroleum Geology · May 2016
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
National Exams, May 2016 — 98-Pet-B3, Oil and Gas Evaluation and Economics (3 hours, closed book, approved non-programmable calculator only). The exam's own cover page is titled "Oil and Gas Evaluation and Economics" and every question is property valuation / reserves & production economics / DCF-NPV screening content — no geology anywhere.
Reference texts: Thompson & Wright, Oil Property Evaluation; Canadian Oil and Gas Evaluation Handbook (COGEH), Vol. 1 (Society of Petroleum Evaluation Engineers, Calgary Chapter); National Instrument 51-101, Standards of Disclosure for Oil and Gas Activities (Canadian Securities Administrators); SPE/WPC/AAPG/SPEE Petroleum Resources Management System (PRMS); Economides & Nolte, Reservoir Stimulation; Ahmed, Reservoir Engineering Handbook.
The exam's own instructions ask for only 7 of the 10 short-answer questions and note the Cash-Flow/Future-Value tables are graded by column; for "choose N of M" exams, every item below is answered in full as a study resource. Questions 1–10 correspond to the exam's printed Short-Answer items 1–10; Questions 11–20 correspond to the printed Multiple-Choice items 1–10; Question 21 is the Future Value table; Question 22 is the Cash Flow table.
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
a. Free gas found in a gas hydrate deposit
b. Gas that is dissolved in oil ← correct
c. Gas that is adsorbed onto coal or shale
d. Gas that is contained in a gas cap
e. None of the above
Answer: (b). “Associated gas” is most commonly used in reserves/evaluation terminology as a synonym for solution (dissolved) gas — gas held in solution in the crude oil below the bubble-point pressure and produced along with it, tracked via the solution gas-oil ratio Rs. (Gas-cap gas, option d, is more precisely termed non-associated free gas that is nonetheless in contact with an oil column; some texts use “associated” loosely to cover both, but the tightest, most commonly examined match is dissolved gas.)
