24-Pet-B4 Well Testing · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Petroleum Engineering, 2014-Dec. 3 hours duration; closed book. This sitting's own cover page reads “98-Pet-B4, Petroleum Geology” and every question is descriptive/interpretive petroleum geology (source rocks, generation, migration, traps, Canadian basin geography) – no well-test pressure-transient content anywhere. Five (5) of the paper's six 20-mark sections are marked (NOTES item 5); all six are solved in full below so this set also serves as a complete study reference. The paper is almost entirely qualitative (draw/describe/define/list), with one true numeric calculation (Q3-2, capillary seal-breach column height).
Reference texts: Selley, R.C. & Sonnenberg, S., Elements of Petroleum Geology, 3rd ed., Academic Press (source rocks, migration, traps); Tissot, B.P. & Welte, D.H., Petroleum Formation and Occurrence, 2nd ed., Springer (kerogen typing, oil/gas windows, primary migration); Boggs, S. Jr., Petrology of Sedimentary Rocks, 2nd ed., Cambridge (source-rock lithofacies); Allen, P.A. & Allen, J.R., Basin Analysis: Principles and Applications to Petroleum Play Assessment, 3rd ed., Wiley-Blackwell (extensional basins, structural styles); Biddle, K.T. & Wielchowsky, C.C., “Trap Types in Petroleum Basins,” AAPG Memoir 60, ch.12 (stratigraphic/structural/salt trap classification); Mossop, G.D. & Shetsen, I. (eds.), Geological Atlas of the Western Canada Sedimentary Basin, CSPG/Alberta Research Council, 1994 (WCSB stratigraphy and play types).
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.
The abiogenic (inorganic) hypothesis holds that hydrocarbons can form directly from inorganic carbon and hydrogen deep in the crust or mantle, independent of buried organic matter. Its case rests on several observations. (1) Laboratory synthesis: Fischer–Tropsch-type reactions readily produce methane and higher alkanes from CO2/CO + H2 over metal-oxide (e.g. magnetite, chromite) catalysts at plausible mantle temperatures and pressures – a purely inorganic chemical pathway that requires no biology at all. (2) Extraterrestrial occurrence: methane and other light hydrocarbons are detected in carbonaceous chondrite meteorites and in the atmospheres/moons of the outer planets (e.g. Titan's methane lakes), environments with no life, showing hydrocarbons can and do form abiotically in nature. (3) Deep, high-temperature occurrences: methane has been sampled venting from ultramafic, olivine-rich rocks at mid-ocean-ridge hydrothermal systems (e.g. the Lost City field), far below and hotter than any sedimentary source-rock interval, where serpentinization reactions (olivine + H2O) generate H2 that then reduces CO2 to methane. (4) Field observations cited by proponents: some crystalline-basement and Precambrian shield reservoirs (e.g. parts of the Dnieper–Donets basin) produce hydrocarbons from rocks with no obvious overlying or adjacent mature source rock, which abiogenic proponents read as evidence of a deep, mantle-derived charge migrating up basement-penetrating faults.
