Skip to main content

Influence of fractures on the reservoir quality of Lower Miocene carbonates in Northern Iraq

Arabian Journal of Geosciences volume 15, Article number: 63 (2022) Cite this article

Abstract

The Zagros Fold and Thrust Belt of the Kurdistan region of northern Iraq host major volumes of hydrocarbons in multiple fractured carbonate reservoirs throughout the Jurassic, Cretaceous, Palaeogene and Neogene. Limited research has been undertaken to characterize these recently discovered carbonate reservoir rocks. Here, the reservoir quality of the Neogene Euphrates and Jeribe Formations is investigated. Samples from five outcrops along the Azhdagh and Mamlaha anticlines and from four nearby wells (North Oil Company wells JM37, KM3, SAR1 and KU1) have been analysed to understand better their reservoir properties. In both formations very low matrix porosities (< 12 ± 0.5%) were measured and no visible pore connectivity was observed in thin sections. Matrix permeability was less than 0.10 ± 0.008 mD. The low porosity of the Euphrates and Jeribe Formation carbonates is related to diagenetic modifications including intense cementation and compaction. Given the low matrix porosity and permeability, the effect of fractures on fluid flow was investigated as a possible mechanism for enhanced reservoir quality. Naturally fractured core samples and highly fractured outcrops for both formations demonstrated enhanced flow of more than three orders of magnitude compared to matrix permeability. Lateral heterogeneities were observed in the area under investigation with lower fracture porosity and permeability in the North East compared to the South West of the region. Outcrop fractures were investigated near the wells on the flanks of the basin. The fracture network was found to be composed of two sets of sub-vertical, perpendicular fracture sets and sub-horizontal bedding. The fractures were closely spaced, persistent, with wide apertures rough surfaces and very well interconnected. The permeability data combined with field fracture survey information provides evidence that the reservoir quality in the drilled wells must in part be a result of a permeable well-interconnected fracture network.

This is a preview of subscription content, access via your institution.

Access options

Buy single article

Instant access to the full article PDF.

USD 39.95

Price includes VAT (USA)
Tax calculation will be finalised during checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

References

  • Agosta F, Aydin A (2006) Architecture and deformation mechanism of a basin-bounding normal fault in Mesozoic platform carbonates, central Italy. J Struct Geol 28:1445–1467

    Article  Google Scholar 

  • Agosta F, Alessandroni M, Antonellini M, Tondi E, Giorgioni M (2010) From fractures to flow: a field-based quantitative analysis of an outcropping carbonate reservoir. Tectonophysics 490:197–213

    Article  Google Scholar 

  • Ahr WM (2008) Geology of carbonate reservoirs: the identification, description, and characterization of hydrocarbon reservoirs in carbonate rocks. Wiley, Hoboken, 296 P

  • Al-Juboury A, Al-Tarif A, Al-Esa M (2007) Basin analysis of the Burdigalian and Early Langhian Successions, Kirkuk basin, Iraq. Geol Soc Lond Spec Publ Vl 258:53–68. https://doi.org/10.1144/Sp285.4

    Article  Google Scholar 

  • Antonellini M, Tondi E, Agosta F, Aydin A, Cello G (2008) Failure modes in deep-water carbonates and their impact for fault development: Majella mountain, Central Apennines. Italy Mar Petrol Geol 25:1074–1096

    Article  Google Scholar 

  • Aqrawi AAM, Goff JC, Horbury AD, Sadooni FN (2010) The petroleum geology of Iraq. Scientific Press Ltd, Beaconsfield

    Google Scholar 

  • Barr D, Savory KE, Fowler SR, Arman K, Mcgarrity JP (2007) Pre-development fracture modelling in the Claire field, West of Shetland. Geol Soc Lond Spec Publ 270:205–225

    Article  Google Scholar 

  • Bisdom K, Bertotti G, Bezerra FH (2017) Inter-well scale natural fracture geometry and permeability variations in low-deformation carbonate rocks. J Struct Geol 97:23–36

    Article  Google Scholar 

  • Buday T (1980) Regional Geology of Iraq, V. 1, Stratigraphy and Paleageography: Dg of Geological Survey and Mineral Investigation

  • Croize D, Renard F, Bjorlykke K, Dysthe DK (2010) Experimental calcite dissolution under stress: evolution of grain contact microstructure during pressure solution creep. J Geophys Res Solid Earth 115:1–15

    Google Scholar 

  • Dashti R, Rahimpour-Bonaba H, Zeinali M (2018) Fracture and mechanical stratigraphy in naturally fractured carbonate reservoirs-a case study from Zagros Region. Mar Pet Geol 97:466–479

    Article  Google Scholar 

  • Dickson JAD (1965) A modified staining technique for carbonates in thin section. Nature 205:587

    Article  Google Scholar 

  • Dickson JAD (1966) Carbonate identification and genesis as revealed by staining. J Sediment Petrol 36:491–505

    Google Scholar 

  • Dou Q, Sun Y, Sullivan C (2011) Rock-physics-based carbonate pore type characterization and reservoir permeability heterogeneity evaluation, Upper San Andres reservoir, Permian Basin, West Texas. J Appl Geophys 74(1):8–18

    Article  Google Scholar 

  • Fossen A (2016) Structural geology. Cambridge University Press, UK, p 524

    Book  Google Scholar 

  • Fossen H, Schultz RA, Torabi A (2011) Conditions and implications for compaction band formation in the Navajo Sandstone, Utah. J Struct Geol 33:1477–1490

    Article  Google Scholar 

  • Garland J, Neilson JE, Laubach SE, Whidden KJ (2012) Advances in carbonate exploration and reservoir analysis. In: Garland J, Neilson JE, Laubach SE, Whidden KJ (eds) Advances in carbonate exploration and reservoir analysis, vol 370. Geological Society of London, Special publication, pp 1–15

    Google Scholar 

  • Graham B, Antonellini M, Aydin A (2003) Formation and growth of normal faults in carbonates within a compressive environment. Geology 31:11–14

    Article  Google Scholar 

  • Haghi AH, Chalaturnyk R, Ghobadi H (2018) The state of stress in SW Iran and implications for hydraulic fracturing of a naturally fractured carbonate reservoir. Int J Rock Mech Min Sci 105:28–43. https://doi.org/10.1016/J.Ijrmms.2018.03.002 (Issn 1365-1609)

    Article  Google Scholar 

  • Hussein D, Collier R, Lawrence J, Rashid F, Glover PWJ, Lorinczi P, Baban DH (2017) Stratigraphic correlation and paleoenvironmental analysis of the hydrocarbon-bearing early Miocene Euphrates and Jeribe formations in the Zagros folded thrust-belt. Arab J Geosci. https://doi.org/10.1007/S12517-017-3342-0

    Article  Google Scholar 

  • Hussein D, Lawrence J, Rashid F, Glover PWJ, Lorinczi P (2018) Developing pore size distribution models in heterogeneous carbonates using especially nuclear magnetic resonance. Engineering in Chalk, Ice Publishing Sbn 978–0–7277–6407–2. https://doi.org/10.1680/Eiccf.64072.529.

  • Jassim SZ, Goff JC (2006) Geology of Iraq: Dolin. Brno, Czech Republic, Prague and Moravian Museum (341p)

    Google Scholar 

  • Jolley S, Barr D, Walsh JJ, Knipe RJ (2007) Structurally complex reservoirs: an introduction. Geol Soc Lond Spec Publ 292(1):1–24

    Article  Google Scholar 

  • Kazemi H, Merrill LS, Porterfield KL, Zeman PR (1976) Numerical simulation of water-oil flow in naturally fractured reservoirs. Society of Petroleum Engineers, pp. 317–326 SPE 5719-PA.

  • Khoshbakht F, Azizzadeh M, Memarian H, Nourozi GH, Moallemi SA (2012) Comparison of electrical image log with core in a fractured carbonate reservoir. J Petrol Sci Eng S86–87(3):289–296

    Article  Google Scholar 

  • Korneva I, Tondi E, Agosta F, Rustichelli A, Spina V, Bitonte R, Di Cuia R (2014) Structural properties of fractured and faulted cretaceous platform carbonates. Murge Plateau (Southern Italy). Mar Pet Geol 57:312–326

    Article  Google Scholar 

  • Kosari E, Kadkhodaie A, Bahroudi A, Chehrazi A, Talebian M (2017) An integrated approach to study the impact of fractures distribution on the Ilam-Sarvak carbonate reservoirs: a case study from the Strait of Hormuz, The Persian Gulf. J Petrol Sci Eng 152:104–115

    Article  Google Scholar 

  • Laubach SE (2003) Practical approaches to identifying sealed and open fractures. AAPG Bull 87:561–579

    Article  Google Scholar 

  • Liu JZ, Sun QY, Xu GM (2008) Research on reservoir fractures in oil-gas field. Petroleum Industry Press, Beijing

    Google Scholar 

  • Micarelli L, Benedicto A, Invernizzi C, Saint-Bezar B, Michelot JL, Vergely P (2005) Influence of p/t conditions on the style of normal fault initiation and growth in limestones from the Se-Basin, France. J Struct Geol 27(9):1577–1598. https://doi.org/10.1016/J.Jsg.2005.05.004

    Article  Google Scholar 

  • Micarelli L, Benedicto A, Wibberley CAJ (2006) Structural evolution and permeability of normal fault zones in highly porous carbonate rocks. J Struct Geol 28(7):1214–1227. https://doi.org/10.1016/J.Jsg.2006.03.036

    Article  Google Scholar 

  • Mu LX, Zhao GL, Tian ZY (2009) Study on reservoir fracture prediction. Petroleum Industry Press, Beijing

    Google Scholar 

  • Nelson RA (1985) Geologic analysis of naturally fractured reservoirs. Gulf publishing company, Houston

    Google Scholar 

  • Nelson RA (2001) Geological analysis of naturally fractured reservoirs. Gulf professional publishing, 2nd Edition, 352 P

  • Olson JE, Dahi-Taleghani A (2009) Modeling simultaneous growth of multiple hydraulic fractures and their interaction with natural fractures. In: Proceedings SPE hydraulic fracturing technology conference and exhibition the Woodlands, Texas, USA; 2009. Paper SPE 119739

  • Peacock DCP, Sanderson DJ, Rotevatn A (2018) Relationships between fractures. J Struct Geol 106:41–53

    Article  Google Scholar 

  • Rashid F, Hussein D, Lawrence J, Khanaqa P (2020) Characterization and impact on reservoir quality of fractures in the Cretaceous Qamchuqa Formation, Zagros folded belt. Mar Pet Geol 113:104–117

    Article  Google Scholar 

  • Rashid F, Glover PWJ, Lorinczi P, Collier R, Lawrence J (2015a) Porosity and permeability of tight carbonate reservoir rocks in the north of Iraq. J Pet Sci Eng 133:147–161

    Article  Google Scholar 

  • Rashid F, Glover PWJ, Lorinczi P, Hussein D, Collier R, Lawrence J (2015b) Permeability prediction in tight carbonate rocks using capillary pressure measurements. Mar Pet Geol 68:536–550

    Article  Google Scholar 

  • Rashid F, Glover PWJ, Lorinczi P, Hussein D, Lawrence J (2017) Microstructural controls on reservoir quality in tight oil carbonate reservoir rocks. J Pet Sci Eng 156:814–826

    Article  Google Scholar 

  • Rustichelli A, Agosta F, Tondi E, Spina V (2013) Spacing and distribution of bed-perpendicular joints throughout layered, shallow-marine carbonates (Granada Basin, Southern Spain). Tectonophysics 582:188–204

    Article  Google Scholar 

  • Tondi E, Rustichelli A, Cilona A, Balsamo F, Storti F, Napoli G, Renda P, Giorgioni M (2016) Hydraulic properties of fault zones in porous carbonates, examples from central and southern Italy. Ital J Geosci 135:68–79. https://doi.org/10.3301/Ijg.2015.08F.1

    Article  Google Scholar 

  • Van Bellen RC, Dunnington H, Wetzel R, Morton D (1959) Lexique Stratigraphique: International, Asie, Iraq. Centre National De La Recherché Scientifique, Paris P. 333

  • Volatili T, Zambrano M, Cilona A, Huisman BAH, Rustichelli A, Giorgioni M, Vittori S, Tondi E (2019) From fracture analysis to flow simulations in fractured carbonates: the case study of the roman valley quarry (Majella Mountain, Italy). Mar Petrol Geol 100(2019):95–110. https://doi.org/10.1016/J.Marpetgeo.2018.10.040 (Issn 0264-8172)

    Article  Google Scholar 

  • Western Zagros (2011) Final well report of well number 1. Kurdamir Licence Block

  • Yu K, Cao Y, Qiu L, Sun P (2018) The hydrocarbon generation potential and migration in an alkaline evaporite basin: the early Permian Fengcheng formation in the Junggar Basin, Northwestern China. Mar Pet Geol 98:12–32

    Article  Google Scholar 

  • Yuan SY, Song XM, Ran QQ (2004) Development technology of fractured reservoirs. Petroleum Industry Press, Beijing

    Google Scholar 

  • Zambrano M, Tondi E, Korneva I, Panza E, Agosta F, Janiseck JM, Giorgioni M (2016) Fracture properties analysis and discrete fracture network modelling of faulted tight limestones, Murge Plateau, Italy. Ital J Geosci 135(1):55–67. https://doi.org/10.3301/Ijg.2014.42

    Article  Google Scholar 

  • Zeng LB, Ke SZ, Liu Y (2010) Study methods of fractures in low-permeability oil-gas reservoirs. Petroleum Industry Press, Beijing

    Google Scholar 

  • Zhou XG, Cao CJ, Yuan JY (2003) The Research actuality and major progresses on the quantitative forecast of reservoir fractures and hydrocarbon migration law. Adv Earth Sci 18(3):398–404

    Google Scholar 

  • Zhou XG, Zhang LY, Fan K (2006) The research situation and progresses of natural fracture for low permeability reservoirs in oil and gas basin. Geol Rev 52(6):777–782

    Google Scholar 

  • Klinkenberg LJ (1941) The permeability of porous media to liquids and gases. American Petroleum Institute, API-41-200

  • Rushing JA, Newsham KE, Lasswell PM, Balsingame TA (2004) Klinkenberg-Corrected Permeability measurements in tight gas sands: SteadyState versus unsteady-state techniques. SPE 89867

  • Tanikawa W, ShimamotoT (2009) Comparison of Klinkenberg-corrected gas permeability and water permeability in sedimentary rocks. International Journal of Rock Mechanics and Mining Sciences 46:229–238

  • Haines TJ, Michie EAH, Neilson JE, Healy D (2016) Permeability evolution across carbonate hosted normal fault zones. Mar Pet Geol 72:62–82

    Article  Google Scholar 

  • Ross ER (2011) Grain’s Petrophysical handbook: online shareware petrophysics. Training and reference manual

  • Rustichelli A, Torrieri S, Tondi E, Laurita S, Strauss C, Agosta F, Balsamo F (2016) Fracture characteristics in Cretaceous platform and overlying ramp carbonates: An outcrop study from Maiella Mountain (central Italy). Mar Pet Geol 76:68–87

  • Lucia FJ (2007) Carbonate reservoir characterization. Springer-Verlag, Berlin, Heidelberg, 331p

  • Miranda TS, Santos RF, Barbosa JA, Gomes IF, Alencar ML, Correia OJ, Falcao TC, Gale JFW, Neumann VH (2018) Quantifying aperture, spacing and fracture intensity in a carbonate reservoir analogue: Crato Formation, NE Brazil. Mar Pet Geol 97:556–567

  • Laubach SE, Diaz-Tushman K (2009) Laurentian paleostress trajectories and ephemeral fracture permeability, Cambrian Eriboll Formation sandstones west of the Moine thrust zone, northwest Scotland. J Geol Soc Lond 166:349–362

Download references

Acknowledgements

We express our gratitude to the Ministry of Natural Resources of Kurdistan Region and the Ministry of Oil of the Iraqi government for providing the project data.

Author information

Authors and Affiliations

  1. Department of Geology, University of Sulaimani, Kurdistan, Iraq

    Devan Hussein

  2. Kurdistan Institution for Strategic Study and Scientific Research, Sulaimani, Iraq

    Fraidoon Rashid

  3. Department of Civil and Environmental Engineering, Imperial College, London, UK

    James A. Lawrence

  4. School of Earth and Environment, University of Leeds, Leeds, UK

    Paul W. J. Glover & Piroska Lorinczi

Authors
  1. Devan Hussein
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Fraidoon Rashid
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. James A. Lawrence
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Paul W. J. Glover
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Piroska Lorinczi
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Devan Hussein.

Ethics declarations

Conflict of interest

The authors declare no competing interests.

Additional information

Responsible Editor: François Roure

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Hussein, D., Rashid, F., Lawrence, J.A. et al. Influence of fractures on the reservoir quality of Lower Miocene carbonates in Northern Iraq. Arab J Geosci 15, 63 (2022). https://doi.org/10.1007/s12517-021-09345-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s12517-021-09345-9

Keywords

  • Fractures
  • Carbonate reservoirs
  • Porosity
  • Permeability
  • Reservoir quality
  • Diagenesis