Reservoir quality and expected fluids for the Ordovician Hawaz sandstone in the NC186 Concession, Murzuq Basin, Libya

  • Mohammad Abdelfattah SarhanEmail author
  • Ahmad Mohammad Kamal Basal
  • Ismail Ali Amhimmid Alabdi
S. I. SCJGE-1 2019
Part of the following topical collections:
  1. Current Advances in Geological Research of Egypt


The present work evaluates the Middle Ordovician Hawaz sandstone reservoir in four wells (A25-NC186, A30-NC186, H2-NC186 and H4-NC186) distributed in the NC186 Concession of Murzuq Basin, Libya. The available well log data set for each well includes: gamma ray, calliper, spontaneous potential, resistivity, density, neutron, sonic, density correction and photoelectric logs. These data have been qualitatively interpreted using Interactive Petrophysics (IP) software and quantitatively analysed by calculating different petrophysical parameters comprising; water saturation, minimum bulk volume of water, absolute permeability, critical water saturation, pressure gradient and fluid density for the promising horizons. The quantitative interpretation has revealed that three horizons (H4, H5 and H6) are suitable for further quantitative interpretation. The calculated petrophysical parameters for these horizons show that all of the studied zones represent oil reservoirs in an irreducible state (i.e. water-free oil production). This finding indicates that the remaining water is located on the pore surfaces as thin films and will not move through the production process. The results reflect excellent reservoir quality for all examined zones, including high porosity (10–26%), high permeability (42–2824 mD), low water saturation (12–43%) less than the critical water saturation (31–45%) and low BVW (0.02–0.06) less than BVWmin (0.07).


Reservoir quality Hawaz Formation NC186 Concession Murzuq Basin 



We give many thanks to the staff of Repsol Oil Company for providing the data in this paper. Thank you to Dr. Adel Keshlaf, lecturer at the Engineering Department, Faculty of Natural Resources, Zawia University, Libya, for the help with applying the Interactive Petrophysics (IP) software, as presented in the current work.


  1. Akakus Oil Operations and Exploration (2007) A5-NC186 final well report by Omran, K. Report No.E05-45Google Scholar
  2. Archie GE (1942) The electrical resistivity log as an aid in determining some reservoir characteristics. Trans AIME 146:54–61CrossRefGoogle Scholar
  3. Basal AMK (1996) Rock wettability determination as an aid for understanding the reservoir performance. Third International Conference of Geology of the Arab World, Cairo University, Cairo, Egypt, pp 647–662Google Scholar
  4. Basal AM, Sarhan MA, Alabdi IA (2019) Effectiveness of minimum bulk volume of water (BVWmin) and minimum true resistivity (Rtmin) for understanding reservoir performance: a case study of Hawaz Formation, Murzuq Basin, Libya. Egypt J Appl Geophys 18(1)Google Scholar
  5. Bassiouni Z (1994) Theory, measurement, and interpretation of well logs, vol 4. Henry L. Doherty Memorial Fund of AIME, Society of Petroleum EngineersGoogle Scholar
  6. Belabed M (2017) Gas-water contacts, free water levels analysis in support of petroleum exploration in offshore Netherlands. Master thesis in Applied Earth Sciences, Delft University of Technology, 55pGoogle Scholar
  7. Bellini E, Massa D (1980) A stratigraphic contribution to the Palaeozoic of southern basins of Libya. In: Salem MJ, Busrewil MT (eds) The geology of Libya, vol I. Academic, London, pp 3–56Google Scholar
  8. Benner FC, Bartel FE (1941) The effect of polar impurities upon capillary and surface phenomena in petroleum production. In: Drilling and production practice. American Petroleum Institute, Washington, D.C.Google Scholar
  9. Bera A, Belhadj H (2016) A comprehensive review on characterization and modeling of thick capillary transition zones in carbonate reservoirs. J Unconv Oil Gas Resour 16:76–89CrossRefGoogle Scholar
  10. Berg RR (1975) Capillary pressures in stratigraphic traps. AAPG Bull 59(6):939–956Google Scholar
  11. Bertello F, Fattorini A, Visentin C, Africa AN (2003) Hydrocarbon discoveries and remaining potential of the Paleozoic play of the Murzuk Basin, Libya. In AAPG Hedberg Conference “Paleozoic and Triassic Petroleum Systems in North Africa” February, pp 18–20Google Scholar
  12. Buckles RS (1965) Correlating and averaging connate water saturation data. J Can Pet Technol 9(1):42–52CrossRefGoogle Scholar
  13. Davidson L, Beswetherick S, Craig J, Eales M, Fisher A, Himmali A, Jho J, Mejrab B, Smart J (2000) The structure, stratigraphy and petroleum geology of the Murzuq basin, southwest Libya. In: Sola MA, Worsley D (eds) Geological exploration in Murzuq basin. Elsevier Science, Amsterdam, pp 295–320CrossRefGoogle Scholar
  14. Elshahawi H, Fathy K, Hiekal S (1999) Capillary pressure and rock wettability effects on wireline formation tester measurements. In: SPE Annual Technical Conference and Exhibition. Society of Petroleum EngineersGoogle Scholar
  15. Fello NM, Turner BR (2001) Provenance analysis, tectonism and shifting depositional system in the NW part of the Murzuq Basin, Libya: implication for hydrocarbon prospectivity. 21st International Association Sedimentology (IAS) meeting of Sedimentology, Abstr., Davos, Switzerland (3rd–5th September 2001)Google Scholar
  16. Fello N, Lüning S, Štorch P, Redfern J (2006) Identification of early Llandovery (Silurian) anoxic palaeo-depressions at the western margin of the Murzuq Basin (southwest Libya), based on gamma-ray spectrometry in surface exposures. GeoArabia 11(3):101–118Google Scholar
  17. Granberry RJ, Keelan DK (1977) Critical water estimate for Gulf Coast Sands, Trans Gulf Coast Assn of Geologic Scientists 27Google Scholar
  18. Johnson DE, Kathryne EP (2006) Well logging in nontechnical language, 2nd edn. Pennwell Corporation, Oklahoma, p 265Google Scholar
  19. Mohamed AK (2016) Reservoir quality of Hawaz formation, J oil field, concession NC186, NW Murzuq basin, SW Libya. Arab J Geosci 9(2):110CrossRefGoogle Scholar
  20. Mohammadi S (2015) Monitoring wettability alteration of poreus media by silica nanoparticles: an experimental approach, Research Institute of Petroleum Industry. Faculty of Research dan Development of Oil Upstream Indusrty, TehranGoogle Scholar
  21. Pierobon EST (1991) Contribution to the stratigraphy of the Murzuq Basin, SW Libya. In: Salem MJ, Belaid MN (eds) The geology of Libya, vol V. Academic, London, pp 1767–1784Google Scholar
  22. Selim EI, Kamel A, Kashlaf A (2015) Hydrocarbon probability of middle Ordovician Hawaz formation, Murzuq basin, southwestern Libya. Arab J Geosci 8(8):5531–5560CrossRefGoogle Scholar
  23. Spearing M, Abdou MK, Azagbaesuweli GA, Kalam MZ (2014) Transition zone behaviour: the measurement of bounding and scanning relative permeability and capillary pressure curves at reservoir conditions for a giant carbonate reservoir. In: Abu Dhabi International Petroleum Exhibition and Conference. Society of Petroleum EngineersGoogle Scholar
  24. Stewart G, Wittmann MJ, van Golf-Racht T (1981) The application of the repeat formation tester to the analysis of naturally fractured reservoirs. In: SPE Annual Technical Conference and Exhibition. Society of Petroleum EngineersGoogle Scholar
  25. Thulin K, Li G, Aanonsen S, Reynolds AC (2007) Estimation of initial fluid contacts by assimilation of production data with EnKF. In: SPE Annual Technical Conference and Exhibition. Society of Petroleum EngineersGoogle Scholar
  26. Timur A (1968) An investigation of permeability, porosity and residual water saturation relationships for sandstone reservoirs. The Log Analyst (July.-Aug.), vol 9, pp 8–17 No. 4Google Scholar

Copyright information

© Saudi Society for Geosciences 2019

Authors and Affiliations

  • Mohammad Abdelfattah Sarhan
    • 1
    Email author
  • Ahmad Mohammad Kamal Basal
    • 1
  • Ismail Ali Amhimmid Alabdi
    • 1
  1. 1.Geology Department, Faculty of ScienceDamietta UniversityNew Damietta CityEgypt

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