Reservoir Characterization and Petrophysical Evaluation for Paleogene Khurmala Formation in Northern Iraq

Rzger Abdulkarim Abdula; Ayub M.   Shwani; Parween R.  Abid; Bienfait K.  Simisi

doi:10.52716/jprs.v15i4.1108

Authors

Rzger Abdulkarim Abdula Soran University, Erbil, Iraq
Ayub M. Shwani Geology Department, Field Division, North Oil Company, Kirkuk, 36001, Iraq
Parween R. Abid Department of Petroleum Geosciences, Soran University
Bienfait K. Simisi 3Geology Department, Université de la Conservation de la Nature et du Développement de Kasugho

DOI:

https://doi.org/10.52716/jprs.v15i4.1108

Keywords:

Khurmala Formation, Reservoir Characterization, Porosity, Permeability, Hydrocarbon potential

Abstract

This study presents a detailed reservoir characterization and petrophysical evaluation of the Paleogene Khurmala Formation within the X Oilfield, northern Iraq. The analysis is based on digitized well log data, including density, neutron porosity, gamma ray, and resistivity logs, processed using Neuralog and Techlog 2018 software. Lithology was determined through neutron-density cross plots, confirming the presence of heterogeneous carbonate sequences consisting of dolomite and limestone. Shale volume was calculated using gamma ray logs, revealing localized shale enrichment in parts of the formation. Effective porosity was derived by correcting density and neutron porosity logs for shale influence, while permeability was estimated through porosity-permeability relationships. Water saturation was calculated using Archie’s equation, indicating that large portions of the formation are water-saturated with low hydrocarbon potential, except for one zone (RU-3) which demonstrates favorable reservoir characteristics. The formation was divided into four reservoir units based on variations in shale content, porosity, water saturation, and permeability. RU-3 exhibited the best petrophysical properties, with high porosity, low water saturation, and minimal shale content, making it the most promising target for hydrocarbon production. The results provide valuable insights for optimizing reservoir management in this field.

References

M. M. Al-Dabagh, “Facies and depositional model of Khurmala Formation (Paleocene-Early Eocene) at selected exposures from northern Iraq”, Unpublished MSc. Thesis, Mosul University, Iraq (in Arabic), 114p., 2010.

R. C. Van Bellen, H. V. Dunnigton, R. Wetzal, and D. M Morton, “Lexique Stratigraphique International”, V. III, 333p., Paris, Centre Recherche Scientifique, Internat. Geol Cong Comm Stratigr, 1959.

B. Al-Qayim, “Sedimentary facies anatomy of Khurmala Formation, northern Iraq”, Iraqi Geological Journal, vol. 28, no. 1, pp. 36-46, 1995.

B. Al Qayim, A. Omer, and H. Koyi, “Tectonostratigraphic overview of the Zagros suture zone, Kurdistan region, northeast Iraq”, GeoArabia, vol. 17, no. 4, pp. 109-156, 2012. https://doi.org/10.2113/geoarabia1704109

K. H. Karim, H. S. Daoud, and A. R. Kuradawy, “Record of Khurmala Formation (Late Paleocene–Early Eocene) in the Sulaimaniyah governorate, Kurdistan region, northeast Iraq”, Iraqi Geological Journal, vol. 51, no. 1, pp. 34-55, 2018. https://doi.org/10.46717/igj.51.1.3Ms-2018-06-25

I. S. Asaad, and S. M. Balaky, “Microfacies analysis and depositional environment of Khurmala Formation (Paleocene–Lower Eocene), in the Zenta village, Aqra district, Kurdistan region, Iraq”, Iraqi Bulletin of Geology and Mining, vol. 14, no. 2, pp. 1-15, 2018.

I. S. Asaad, M. A. Al-Haj, and Z. A. Malak, “Depositional setting of Khurmala Formation (Paleocene-Early Eocene) in Nerwa section, Berat Anticline, Kurdistan Region, Northern Iraq”, Iraqi Geological Journal, vol. 55, no. 1F, pp. 20-39, 2022. https://doi.org/10.46717/igj.55.1F.2Ms-2022-06-17

S. I. Al-Sakry, “Sequence stratigraphy of the Paleocene – Lower Eocene succession, northeastern Iraq”, Unpublished Ph.D. Thesis, Baghdad University, Iraq, 240p, 2006.

Ch. A. Karim, “Stratigraphical and paleontological study of Khurmala Formation (Paleocene – Lower Eocene) in Shaqlawa Area -Northern Iraq”, Unpublished MSc. Thesis, Mosul University, Iraq, 103p, 2009.

N. M. Salih, “Stratigraphy and paleoenvironment of the Khurmala and Sinjar formations at Shira Swar, Shinawa and Bekhme in Kurdistan Region, Northeastern Iraq”, Unpublished M.Sc. Thesis, Erbil, University of Salahaddin-Erbil, 157p, 2010.

M. Y. Tamar-Agha, A. L. Salih, A. A. Al-Zaidy, 2015. Depositional setting and basin development of the Paleocene—Lower Eocene Sinjar and Khurmala formations, Northern Iraq”, Arabian Journal of Geosciences, vol. 8, no. 11, pp. 9441-9467. https://doi.org/10.1007/s12517-015-1871-y

A. Barzani, “Lithostratigraphy and microfacies analysis of the Khurmala Formation, Duhok Area, Kurdistan region, Iraq”, MSc. Thesis, University of Sulaimani, Iraq, 113p, 2020.

S.Z. Jassim and T. Buday, 2006. Middle Palaeocene-Eocene Megasequence AP10, chapter 13, in: S.Z. Jassim and J.C. Goff (eds.), “Geology of Iraq”, first edition: Brno, Czech Republic, Prague and Moravian Museum, pp. 205-227, 2006.

P. R. Sharland, D. M. Casey, R. B. Davies, M. D. Simmons, and O. E. Sutcliffe, “Arabian plate sequence stratigraphy–revisions to SP2”, GeoArabia, vol. 9, no. 1, pp. 199-214, 2004.

T. Buday, “The Regional Geology of Iraq” Vol. 1, Stratigraphy and paleogeography. Dar Al-Kutub Publication University of Mosul, Iraq, 445p, 1980.

R. A. Abdula, H. S. Hussein, M. S. Hamad, and A. M. Abdulla, “Reservoir characterization of the Paleogene Khurmala Formation in Tawke and Shaqlawa areas, Kurdistan Region of Iraq”, Iraqi Geological Journal, vol. 57, no. 1C, pp. 62-77, 2024. https://doi.org/10.46717/igj.57.1C.5ms-2024-3-17

M. Rider, “The geological interpretation of well logs”, 2nd ed., Sutherland: Rider-French Consulting Ltd, 2002.

M. Ghorab, A. M. Ramadan, and A. Z. Nouh, “The relation between the shale origin (source or non-source) and its type for Abu Roash Formation at Wadi El-Natrun area, south of Western Desert, Egypt”, Australian Journal of Basic and Applied Sciences, vol. 2, no. 3, pp. 360–371, 2008.

O. Horsfall, V. Omubo-Pepple, and I. Tamunobereton-Ari, “Correlation analysis between sonic and density logs for porosity determination in the south-eastern part of the Niger Delta Basin of Nigeria”, Asian Journal of Science and Technology, vol. 4, no. 3, pp. 1-5, 2013.

F. K. North, “Petroleum geology”, Boston: Allen amp Unwin, 607p, 1985.

G.B. Asquith, D. Krygowski, and C.R. Gibson, “Basic well log analysis”, Tulsa: American Association of Petroleum Geologists AAPG, vol. 16, pp. 305-371, 2004.

D. Tiab and E. C. Donaldson, “Petrophysics: Theory and practice of measuring reservoir rock and fluid transport properties”, 4th ed., Boston: Gulf Professional Publishing, pp. 260-628, 2015.

Schlumberger, “Log interpretation/charts”, Houston, USA: Schlumberger Wireline and Testing, 1997.

S. Mohaghegh, B. Balan, and S. Ameri, “Permeability determination from well log data”, SPE formation evaluation, vol. 12, no. 3, pp. 170-174, 1997. https://doi.org/10.2118/30978-PA