Type of Document Dissertation Author ALTEMIMI, KHALAF O URN etd-05142012-161259 Title SEQUENCE DEVELOPMENT AND DOLOMITIZATION OF A LATE JURASSIC GIANT OIL RESERVOIR, ARAB-D RESERVOIR, HAWIYAH (GHAWAR) and HARMALIYAH FIELDS, SAUDI ARABIA Degree PhD Department Geosciences Advisory Committee
Advisor Name Title Read, James Fredrick Committee Chair Al-Tawil, Aus Committee Member Bodnar, Robert J. Committee Member Eriksson, Kenneth A. Committee Member Keywords
- Late Jurassic
- Sequence Stratigraphy
Date of Defense 2012-04-30 Availability unrestricted AbstractThirty cores from the Late Jurassic uppermost Jubaila, Arab-D reservoir and Arab-D anhydrite in Hawiyah (Ghawar) and Harmaliyah fields, eastern Saudi Arabia were studied to document the detailed facies stacking and high resolution sequence stratigraphy. The Jubaila-Arab-D interval is a shallowing upward succession of two composite sequences, in which the Arab-D reservoir and overlying anhydrite have up to twelve higher frequency sequences.
Both fields are strikingly similar in terms of facies, parasequences, and vertical stacking of facies. The direction of the progrodaion is east and northeast and that is supported by northeast thickening of the Arab-D reservoir and by the stromatoporoid and Cladocoropsis facies progrodation. This suggests that the Arab-D reservoirs in both fields may represent part of a single carbonate ramp with subtle syndepositional highs. The scarcity of exposure surfaces with caliche in the Arab-D reflects the relatively high subsidence rate (~6 cm/k.y.) relative to the small sea level oscillations that formed the succession coupled with the long term shallowing trend up through the section.
Dolomites from the Arab-D reservoir zones 1 to 4, in both fields were studied to better understand their origin. The dolomites are dominantly fabric destructive medium to coarse grained types, and much less common fabric retentive finer grained dolomites in the uppermost Arab-D reservoir. The δ13C values are rock buffered while the δ18O values have been greatly shifted toward negative values relative to unaltered early dolomite, and dolomite crystal rims generally have lighter δ18O values than cores.
The dolomites were initiated at different times during shallowing phases on the Arab-D platform, with the bulk of the fabric destructive dolomites forming under near normal salinities, while the fabric preserving dolomites formed as a result of dolomitizing aragonitic sediments from more evaporated waters. With increasing burial and increasing temperature, the early dolomites re-equilibrated with the increasingly warm basinal brines resulting in replacement of cores, and dolomite cementation by rim overgrowth. Progressive plugging of higher dolomites earlier, caused some of these to retain slightly heavier δ18O values and marine seawater Sr isotope values while those that remained permeable developed very light δ18O values and more radiogenic Sr values, shifting them toward the field of late stage baroque dolomite.
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access Altemimi_KO_D_2012.pdf 12.40 Mb 00:57:24 00:29:31 00:25:50 00:12:55 00:01:06
If you have questions or technical problems, please Contact DLA.