24-Pet-B4 Well Testing · December 2015
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Petroleum Engineering, 2015-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, hydrocarbon chemistry, migration/unconventional reservoirs, carbonate traps, structural 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, carbonate systems); Tissot, B.P. & Welte, D.H., Petroleum Formation and Occurrence, 2nd ed., Springer (kerogen typing, maceral groups, catagenesis); Boggs, S. Jr., Petrology of Sedimentary Rocks, 2nd ed., Cambridge (source-rock and carbonate lithofacies); Allen, P.A. & Allen, J.R., Basin Analysis: Principles and Applications to Petroleum Play Assessment, 3rd ed., Wiley-Blackwell (structural styles, unconventional systems); Biddle, K.T. & Wielchowsky, C.C., “Trap Types in Petroleum Basins,” AAPG Memoir 60, ch.12 (structural trap classification); James, N.P. & Jones, B., Origin of Carbonate Sedimentary Rocks, Wiley-Blackwell (carbonate platform/ramp/sabkha facies models); Law, B.E. & Curtis, J.B., “Introduction to unconventional petroleum systems,” AAPG Bulletin 86 (basin-centred gas); Mossop, G.D. & Shetsen, I. (eds.), Geological Atlas of the Western Canada Sedimentary Basin, CSPG/Alberta Research Council, 1994 (WCSB stratigraphy and Canadian basin geography).
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 WCSB is a classic asymmetric foreland basin: Precambrian Shield basement outcrops at surface in the northeast and dips gently southwest beneath a wedge of Paleozoic and Mesozoic strata that thickens dramatically toward the Rocky Mountain deformed belt, where the same section is structurally thickened again by thrust stacking. Along the section (NE→SW): (A) at the shallow NE subcrop edge, Lower Cretaceous Mannville Group (McMurray Fm) sands host the Athabasca oil sands – a biodegraded heavy-oil/bitumen play (Q3-5); (B) across the central basin, Devonian carbonate platform and reef buildups (Leduc, Nisku, Wabamun) form major structural-stratigraphic reef-trend plays; (C) overlying Cretaceous clastic wedges (Cardium, Viking, Mannville sands) host stratigraphic/tight oil and gas plays across the basin; (D) toward the deep foredeep, thick, low-permeability foreland clastics host basin-centred (deep basin) gas accumulations (Q3-3); and (E) in the Rocky Mountain foothills/deformed belt itself, thrust-faulted and folded Paleozoic–Mesozoic carbonates and clastics host structural (fold-and-thrust) gas plays of the type described in Q5-1.
