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.
[Figure not reproduced: Map A: hydrocarbons generated in the central, structurally deep mature-source kitchen migrate updip (buoyancy-driven) radially outward along the domal contours; the western-flank normal fault can pond migrating charge on its downthrown (eastern) side if it juxtaposes reservoir against seal, making t. See the official exam paper.]
Map A – domal closure centred on the source kitchen. The mature source rock occupies the structurally lowest, most deeply buried (and hence hottest) part of the map, at the centre of a set of concentric contours that shallow outward – a classic synclinal/basinal kitchen setting. Once expelled, hydrocarbons migrate updip along the dip of the carrier bed, i.e. radially outward from the centre toward the shallower flanks, under buoyancy. The normal fault crossing the western flank (downthrown block toward the centre/east) is a candidate lateral seal or leak point depending on juxtaposition; treated as a potential seal here, it is ranked target 1 because migrating hydrocarbons moving up the western flank pond directly against it. The two most fully developed, farthest-updip domal noses on the unfaulted eastern/southern flanks (longest updip focusing distance, least structural complication) are ranked targets 2 and 3.
Map B – source kitchen against a reverse fault, fold belt beyond. The mature source occupies the western block; the reverse fault forms its eastern boundary, upthrown to the east. Migrating hydrocarbons move eastward and updip out of the kitchen, crossing (or migrating along) the fault into the adjacent fold belt, where they are captured by the first structural closures encountered. Of the three anticlines and two synclines in the fold belt, only the anticlines can trap updip-migrating charge (synclines are structural lows relative to their surroundings and cannot hold buoyant hydrocarbons against further updip flow); the top three targets (1–3) are therefore the three anticlinal crests, prioritized by proximity to the fault/kitchen (shortest migration distance, least chance of charge loss to leakage or biodegradation en route), which in this layout are the two anticlines nearest the fault first, then the more distal one.
