Petrophysical study of the Rumaila Formation in Ratawi Oil Field, Southern Iraq

Hameed, Ali Saad; Hameed, Humam Qusai; Mohammed, Osama Jasim; Hamzah, Raafat Abdulghafoor; Mhameed, Zeyad Najeh

doi:10.37652/juaps.2026.165159.1688

[1] Liu H, Shi K, Liu B, Song X, Guo R, Wang G, et al. Microfacies and Reservoir Quality of the Middle Cretaceous Rumaila Formation in the AD Oilfield, Central Mesopotamian Basin, Southern Iraq. Journal of Asian Earth Sciences. 2021;213:104726. 10.1016/j.jseaes.2021.104726

[2] Ehrenberg SN, Aqrawi AAM, Nadeau PH.An Overview of Reservoir Quality in Producing Cretaceous Strata of the Middle East.Petroleum Geoscience. 2008;14(4):307-18.10.1144/1354-079308-783

[3] Nairn AEM, Alsharhan AS. Sedimentary Basins and Petroleum Geology of the Middle East. 1st ed. Amsterdam: Elsevier Science; 1997.10.1016/B978-0-444-82465-3.X5000-1

[4] Ashoor R, Nabawy BS, Kamel A. Formation Evaluation and Reservoir Quality Assessment of the Albian Clastic Sequence in the SWM Oilfield, Southwest the Mesopotamian Basin, Iraq. Journal of Petroleum Exploration and Production Technology. 2023;13(2):553-76. 10.1007/s13202-022-01563-5

[5] Sadooni FN, Aqrawi AAM. Cretaceous Sequence Stratigraphy and Petroleum Potential of the Mesopotamian Basin, Iraq. In: Alsharhan AS, Scott RW, editors. Middle East Models of Jurassic/Cretaceous Carbonate Systems. No. 69 in SEPM Special Publication. Tulsa, Oklahoma: SEPM Society for Sedimentary Geology; 2000. p. 315-34.10.2110/pec.00.69.0315

[6] Aqrawi AAM, Khaiwka MH.Microfacies Analysis of the Rumaila Formation and Equivalents (Cenomanian) in the Mesopotamian Basin: A Statistical Approach. Journal of the University of Kuwait (Science). 1989;16:143-53

[7] Mozan GM, Salman AE. Reinterpretation of Seismic Data on Ratawi Field.Baghdad, Iraq: Oil Exploration Company; 2014. Unpublished report; no DOI identified. The DOI supplied by the author, 10.22161/ijaers.4.12.4, belongs to a different 2017 article and has therefore been removed

[8] Jassim SZ, Goff JC, editors. Geology of Iraq. Prague and Brno: DOLIN and Moravian Museum; 2006. Distributed by the Geological Society of London

[9] Awadeesian AMR, Al-Jawad SNA, Awadh SM, Al-Maliki MM. Chronostratigraphically Based Reservoir Model for Cenomanian Carbonates, Southeastern Iraq Oilfields. Iraqi Geological Journal. 2018;51(2):1-27. 10.46717/igj.51.2.1ms-2018-12-23

[10] Tareq H, Al-Banna A, Al-Sharaa G. Lithological Study of Mishrif, Rumaila, Ahmadi and Mauddud Formations Using Vp/Vs Ratio, Acoustic Impedance and Well Logging at Amara Oil Field, Southern Iraq. Iraqi Geological Journal. 2021;54(2D):39-58. 10.46717/igj.54.2D.4Ms-2021-10-23

[11] Radhi FA, Al-Fatlawi O. Petrophysical Characterization and Lithology of the Mishrif Formation in Ratawi Oil Field, Southern Iraq. Iraqi Geological Journal. 2024;57(2F):195-215. 10.46717/igj.57.2F.13ms-2024-12-23

[12] Mohammad OJ, Al-Kubaisi BF, Al-Hetty SO, Al-Jibouri AS. Petrophysical Evaluation of the Rumaila Formation via Well Logs: A Case Study of the Q Oilfield, Southern Iraq. Iraqi Geological Journal. 2025;58(1A):30-9. 10.46717/igj.58.1A.3ms-2025-1-13

[13] Mahdi MM, Ismail MJ, Mohammad OAM.The Integration of Wireline Logs and Sedimentological Data to Predict Sequence Stratigraphic Framework in Carbonate Rocks: An Example from Rumaila Formation (Cenomanian), West Qurna Oil Field, Southern Iraq. Stratigraphy and Geological Correlation. 2022;30(5):360-77.10.1134/S0869593822050045

[14] Asquith GB, Gibson CR.Basic Well Log Analysis for Geologists. vol. 3 of Methods in Exploration Series.Tulsa, Oklahoma: American Association of Petroleum Geologists; 1982

[15] Selley RC.Elements of Petroleum Geology.2nd ed. San Diego: Academic Press; 1998

[16] Calvert SEE.Log Interpretation in Horizontal Wells.Leicester, United Kingdom: University of Leicester; 2002.PhD thesis

[17] Ben CC, Tamunobereton-ari I, Opiriyabo HI. Determination of Porosity–Permeability Correlation with Pressure and Depth in Part of Niger Delta Basin, Nigeria. Earth Sciences Malaysia. 2021;5(2):114-21. 10.26480/esmy.02.2021.114.121

[18] Hameed AS, Faisal RF. Petrophysical Properties of Mauddud Formation in Selected Wells in Al-Ahdab Oil Field, Middle Iraq. Iraqi Journal of Science. 2023;64(2):718-29. 10.24996/ijs.2023.64.2.20

[19] Mamaseni WJ, Naqshabandi SF, Al-Jaboury FK. Petrophysical Properties of the Lower Cretaceous Formations in the Shaikhan Oilfield, Northern Iraq.Earth Sciences Research Journal. 2018;22(1):45-52.10.15446/esrj.v22n1.66088

[20] Hamzah RA, Al-Kubaisi MS, Jaafar AD. Petrophysical Evaluation of Mishrif Formation in X Oilfield, Southeastern Iraq. Iraqi Geological Journal. 2022;55(2E):96-110. 10.46717/igj.55.2E.6ms-2022-11-20

	Petrophysical study of the Rumaila Formation in Ratawi Oil Field, Southern Iraq
Journal of University of Anbar for Pure Science
Volume 20, Issue 2, August 2026, Pages 413-422 PDF (14.75 M)
Document Type: Research Paper
DOI: 10.37652/juaps.2026.165159.1688
Authors
Ali Saad Hameed¹; Humam Qusai Hameed²; Osama Jasim Mohammed³; Raafat Abdulghafoor Hamzah^* ¹; Zeyad Najeh Mhameed⁴
¹Department of Chemical and Petrochemical Engineering, College of Engineering, University of Anbar, Heet, Iraq
²Middle Oil Company, Heet, Iraq
³University of Anbar - College of Science - Department of Applied Geology, Heet, Iraq
⁴Department of Biology, College of Education, University of Fallujah, Fallujah, Iraq
Abstract
The objective of this study was to evaluate the petrophysical characteristics of the Rumaila Formation in the Ratawi Oilfield by integrating reservoir and well-log data. Well-log interpretation was performed using IP 2018 software, version 4.5. Key petrophysical properties, including shale volume (0.067-0.62), effective porosity (0.06-0.239), and water saturation (0.48-0.69), were calculated and interpreted. Based on variations in these properties, the formation was subdivided into four main units (Ru-1-Ru-4), representing different reservoir-quality levels. Distinct differences were observed among the selected wells. In well RT-26, units Ru-4 and Ru-2 displayed average properties, whereas all units in well RT-24 exhibited fair-to-good parameters. All units in well RT-25 exhibited poor properties, indicating deterioration in reservoir quality within the central dome area. Computed petrophysical interpretation (CPI) revealed clear horizontal and vertical heterogeneity in the reservoir properties, with a gradual improvement from the northeast to the southwest. Matrix identification (MID) data and petrographic investigations further supported these results, confirming the dominance of calcite as the principal mineral and reinforcing the interpretation that the formation rocks are primarily composed of limestone. The study also employed a three-dimensional (3D) contour map, generated using Petrel software, to illustrate the structural and geographical extent of the reservoir. The findings contribute to establishing an accurate knowledge base for reservoir characterization, thereby supporting field-development strategies and production optimization in the Ratawi Oilfield.
Keywords
Interactive petrophysical software IP; (M-N)Cross-Plots; Ratawi Oil Field; Rumaila Formation

References
[1] Liu H, Shi K, Liu B, Song X, Guo R, Wang G, et al. Microfacies and Reservoir Quality of the Middle Cretaceous Rumaila Formation in the AD Oilfield, Central Mesopotamian Basin, Southern Iraq. Journal of Asian Earth Sciences. 2021;213:104726. 10.1016/j.jseaes.2021.104726 [2] Ehrenberg SN, Aqrawi AAM, Nadeau PH.An Overview of Reservoir Quality in Producing Cretaceous Strata of the Middle East.Petroleum Geoscience. 2008;14(4):307-18.10.1144/1354-079308-783 [3] Nairn AEM, Alsharhan AS. Sedimentary Basins and Petroleum Geology of the Middle East. 1st ed. Amsterdam: Elsevier Science; 1997.10.1016/B978-0-444-82465-3.X5000-1 [4] Ashoor R, Nabawy BS, Kamel A. Formation Evaluation and Reservoir Quality Assessment of the Albian Clastic Sequence in the SWM Oilfield, Southwest the Mesopotamian Basin, Iraq. Journal of Petroleum Exploration and Production Technology. 2023;13(2):553-76. 10.1007/s13202-022-01563-5 [5] Sadooni FN, Aqrawi AAM. Cretaceous Sequence Stratigraphy and Petroleum Potential of the Mesopotamian Basin, Iraq. In: Alsharhan AS, Scott RW, editors. Middle East Models of Jurassic/Cretaceous Carbonate Systems. No. 69 in SEPM Special Publication. Tulsa, Oklahoma: SEPM Society for Sedimentary Geology; 2000. p. 315-34.10.2110/pec.00.69.0315 [6] Aqrawi AAM, Khaiwka MH.Microfacies Analysis of the Rumaila Formation and Equivalents (Cenomanian) in the Mesopotamian Basin: A Statistical Approach. Journal of the University of Kuwait (Science). 1989;16:143-53 [7] Mozan GM, Salman AE. Reinterpretation of Seismic Data on Ratawi Field.Baghdad, Iraq: Oil Exploration Company; 2014. Unpublished report; no DOI identified. The DOI supplied by the author, 10.22161/ijaers.4.12.4, belongs to a different 2017 article and has therefore been removed [8] Jassim SZ, Goff JC, editors. Geology of Iraq. Prague and Brno: DOLIN and Moravian Museum; 2006. Distributed by the Geological Society of London [9] Awadeesian AMR, Al-Jawad SNA, Awadh SM, Al-Maliki MM. Chronostratigraphically Based Reservoir Model for Cenomanian Carbonates, Southeastern Iraq Oilfields. Iraqi Geological Journal. 2018;51(2):1-27. 10.46717/igj.51.2.1ms-2018-12-23 [10] Tareq H, Al-Banna A, Al-Sharaa G. Lithological Study of Mishrif, Rumaila, Ahmadi and Mauddud Formations Using Vp/Vs Ratio, Acoustic Impedance and Well Logging at Amara Oil Field, Southern Iraq. Iraqi Geological Journal. 2021;54(2D):39-58. 10.46717/igj.54.2D.4Ms-2021-10-23 [11] Radhi FA, Al-Fatlawi O. Petrophysical Characterization and Lithology of the Mishrif Formation in Ratawi Oil Field, Southern Iraq. Iraqi Geological Journal. 2024;57(2F):195-215. 10.46717/igj.57.2F.13ms-2024-12-23 [12] Mohammad OJ, Al-Kubaisi BF, Al-Hetty SO, Al-Jibouri AS. Petrophysical Evaluation of the Rumaila Formation via Well Logs: A Case Study of the Q Oilfield, Southern Iraq. Iraqi Geological Journal. 2025;58(1A):30-9. 10.46717/igj.58.1A.3ms-2025-1-13 [13] Mahdi MM, Ismail MJ, Mohammad OAM.The Integration of Wireline Logs and Sedimentological Data to Predict Sequence Stratigraphic Framework in Carbonate Rocks: An Example from Rumaila Formation (Cenomanian), West Qurna Oil Field, Southern Iraq. Stratigraphy and Geological Correlation. 2022;30(5):360-77.10.1134/S0869593822050045 [14] Asquith GB, Gibson CR.Basic Well Log Analysis for Geologists. vol. 3 of Methods in Exploration Series.Tulsa, Oklahoma: American Association of Petroleum Geologists; 1982 [15] Selley RC.Elements of Petroleum Geology.2nd ed. San Diego: Academic Press; 1998 [16] Calvert SEE.Log Interpretation in Horizontal Wells.Leicester, United Kingdom: University of Leicester; 2002.PhD thesis [17] Ben CC, Tamunobereton-ari I, Opiriyabo HI. Determination of Porosity–Permeability Correlation with Pressure and Depth in Part of Niger Delta Basin, Nigeria. Earth Sciences Malaysia. 2021;5(2):114-21. 10.26480/esmy.02.2021.114.121 [18] Hameed AS, Faisal RF. Petrophysical Properties of Mauddud Formation in Selected Wells in Al-Ahdab Oil Field, Middle Iraq. Iraqi Journal of Science. 2023;64(2):718-29. 10.24996/ijs.2023.64.2.20 [19] Mamaseni WJ, Naqshabandi SF, Al-Jaboury FK. Petrophysical Properties of the Lower Cretaceous Formations in the Shaikhan Oilfield, Northern Iraq.Earth Sciences Research Journal. 2018;22(1):45-52.10.15446/esrj.v22n1.66088 [20] Hamzah RA, Al-Kubaisi MS, Jaafar AD. Petrophysical Evaluation of Mishrif Formation in X Oilfield, Southeastern Iraq. Iraqi Geological Journal. 2022;55(2E):96-110. 10.46717/igj.55.2E.6ms-2022-11-20
Statistics Article View: 142 PDF Download: 85