Comparison of the Petrophysical Properties of the Zubair Formation in the Rumaila and West Qurna Oil Fields, Southern Iraq
DOI:
https://doi.org/10.24237/04.02.603Keywords:
Petrophysical properties , comparison, Rumaila oil field , Zubair Formation, West Qurna oil fieldAbstract
The Early Cretaceous Zubair Formation is a key clastic reservoir in southern
Iraq, but reservoir quality varies laterally between major fields. To evaluate
and compare Zubair Formation petrophysical properties in the Rumaila and
West Qurna oil fields and determine the main pay intervals and producibility.
Open hole logs from four wells (RU145, R25, WQ1, WQ3) were quality
checked, environmentally corrected, and interpreted using Interactive
Petrophysics (IP v3.5). Shale volume was derived from gamma ray, lithology
was identified using GR response, density–neutron crossover, PEF and
crossplots, and porosity and fluid saturations were computed (including
Indonesia watersaturation modeling). The formation is subdivided into upper,
middle, and lower zones. Shale volume and carbonate content increase toward
West Qurna, while effective porosity and hydrocarbon saturation improve
toward Rumaila (highest in RU145). The middle sand member is the main pay
zone, partitioned into reservoir units ZM1–ZM3 separated by barriers B1 and
B2; West Qurna shows weak oil indications due to high shale and water
saturation.
Zubair Formation is producible in Rumaila, but largely
nonproducible in West Qurna because increased shale and water saturation
degrade porosity and permeability.
Downloads
References
[1] Z. Abdallah, A. M. Handhal, and R. A. AlAli, “Petrophysical Evaluation of the Zubair Formation’s Main Pay Zone Using Conventional and NMR Log Data: Insights from the North Rumaila Field, Southern Iraq,” Iraqi Geological Journal, vol. 58, no. 1D, pp. 103–122, Apr. 2025. https://doi.org/10.46717/igj.2025.58.1D.7
[2] H. AlAraidi, F. Alnajim, and A. AlKhafaji, “Reservoir Properties of the Upper Sand Member of the Zubair Formation in North Rumaila Oil Field,” Iraqi Geological Journal, vol. 55, no. 1C, pp. 97–111, Mar. 2022. https://doi.org/10.46717/igj.55.1C.8Ms20220327
[3] C. H. Ali, “Yamama reservoir characterization in the West Qurna oil field, Southern Iraq,” Iraqi Journal of Science, vol. 57, no. 2A, pp. 938–947, 2016. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/7465
[4] T. K. AlAmeri et al., “Programed oil generation of the Zubair Formation, Southern Iraq oil fields: Results from PetroMod software modeling and geochemical analysis,” Arabian Journal of Geosciences, vol. 4, no. 7, pp. 1239–1253, 2011. https://doi.org/10.1007/s125170100160z
[5] A. M. Abdulaziz, A. S. A. Dahab, and M. Y. Najmuddin, “Well log petrophysics of the Cretaceous pay zones in Zubair Field, Basrah, South Iraq,” Open Journal of Geology, vol. 7, no. 10, pp. 1552–1568, 2017. https://doi.org/10.4236/ojg.2017.710104
[6] R. C. van Bellen, H. V. Dunnington, R. Wetzel, and D. M. Morton (eds.), Lexique Stratigraphique International, vol. III, Asie, Fascicule 10a: Iraq. Paris: Centre National de la Recherche Scientifique (CNRS), 1959, 333 p.
[7] V. V. Larionov, Borehole Radiometry. Moscow, U.S.S.R.: Nedra, 1969, 127 p.
[8] G. B. Asquith and C. R. Gibson, Basic Well Log Analysis for Geologists. Tulsa, OK, USA: American Association of Petroleum Geologists (AAPG), 1982, 216 p. https://doi.org/10.1306/MTH3425
[9] M. R. J. Wyllie, A. R. Gregory, and L. W. Gardner, “Elastic wave velocities in heterogeneous and porous media,” Geophysics, vol. 21, no. 1, pp. 41–70, 1956. https://doi.org/10.1190/1.1438217
[10] R. Desbrandes, Encyclopedia of Well Logging. Paris: Éditions Technip (Institut Français du Pétrole), 1985.
[11] G. Asquith, D. Krygowski, S. Henderson, and N. Hurley, “Basic relationships of well log interpretation,” 2004. https://doi.org/10.1306/MTH16823C1
[12] D. A. Krygowski, Guide to Petrophysical Interpretation. 2003.
[13] J. Bowler, “The LithoDensity Log,” The APPEA Journal, vol. 21, no. 1, pp. 200–212, 1981. https://doi.org/10.1071/AJ80022
[14] H. A. AlSamer and F. M. AlNajm, “Petrophysical and Statistical Analysis of Main Pay of the Zubair Formation in South Rumaila Oil Field,” Iraqi Journal of Science, vol. 65, no. 1, pp. 210–222, 2024. https://doi.org/10.24996/ijs.2024.65.1.19.
[15] Z. M. H. ALTool, I. A. Allamalah, and F. M. AlNimj, “Petrophysical properties evaluation using well logging of the upper sand member of Zubair Formation in Zubair oil Field, Southern Iraq,” Basrah Journal of Science, vol. 37, pp. 456–480, 2019, https://doi.org/10.2907/basjs.201903089.
[16] H. AlAraji, F. Alnajim, and A. AlKhafaji, “Reservoir Properties of the Upper Sand Member of the Zubair Formation in North Rumaila Oil Field,” Iraqi Geological Journal, vol. 55, no. 1, pp. 97–111, 2022, https://doi.org/10.46717/jgi.55.1.3.CSmos202203.
[17] M. S. Aljawad, A. A. Ali, and M. D. Abdulkhadim, “Comparison of Petrophysical Properties Measurement Methods in Sandstone Rocks,” Iraqi Journal of Chemical and Petroleum Engineering, vol. 19, no. 2, pp. 15–20, Jun. 2018. https://doi.org/10.31699/IJCPE.2018.2.3
[18] H. A. Hussein, H. A. Al-Saad, and A. M. Handhal, “Determining Petrophysical Properties Using PLTs and Conventional Logs of the Middle Shale Member (4th Pay) of the Zubair Formation in the South Rumaila Oil Field, Southern Iraq,” Iraqi Geological Journal, vol. 57, no. 2(E), pp. 183–204, 2024. https://doi.org/10.46717/igj.57.2E.15ms-2024-11-24
Downloads
Published
Issue
Section
License
Copyright (c) 2026 CC BY 4.0
This work is licensed under a Creative Commons Attribution 4.0 International License.
