Diagenetic History and Porosity Evaluation of the Albian-Aptian  Succession in BaladOil Field, Central of Iraq

Zainab  Amer; Aiad Ali Hussien Al-Zaidy; Mohammed Sulaiman

doi:10.48165/

Authors

Zainab Amer Department of Civil Engineering, AL-Esraa University College, Baghdad-Iraq
Aiad Ali Hussien Al-Zaidy Department of Geology, College of Sciences, University of Baghdad, Baghdad-Iraq
Mohammed Sulaiman Oil Exploration Company - Ministry of Oil, Baghdad-Iraq

DOI:

https://doi.org/10.48165/

Keywords:

Diagenetic history, Porosity evaluation, Albian-Aptian succession, Balad oil field Zainab Amer, Aiad Ali Hussien Al-Zaid, Mohammed Sulaiman

Abstract

Carbonate-clastic succession which includes the Shu'aiba, Nahr Umr and Mauddud formations are representing a part of Barremian-Aptian Sequence (Wasi'a Group). The present study includes three boreholes; Balad-1, Balad-4 and Balad-8within the Balad Oil Field. The most common diagenetic features observed in the studied sections include micritization, cementation, leaching (dissolution), dolomitization and compaction fabrics in carbonate rocks. While the calstic rocks effected by cementation, compaction, dissolution processes. The Albian-Aptian succession in the study area is affected by many types of diagenetic processes during and post deposition. There are three diagenetic zones in this succession; the first within Shuaiba Formation which characterized by high compacted limestone and dolomitization in all studied wells with low porosity values. The second within Nahr Umr Formation is characterized by different diagenetic patterns in the studied area, where appeared in Ba-1 three late diagenetic subzone within sandstone units. These zones are affected by dissolution process to product an affective porous unit, and separated them by cemented and compacted zones. To the south of study area (Ba-4) these subzones became less porosity values and the early and moderate diagenetic stages (cemented and compacted) were common. To the north the clastic succession was characterized by one affective porous unit and dominantly by cemented and compacted zones. The third upper zone within Mauddud succession is characterized by two high effective porous units with dominance of dissolution process in the upper part of Mauddud Formation in Ba-1. While the lower part of this formation is affected by cementation and dolomitization (early and moderate diagenetic stage) with a breakdown for primary and secondary porosities. To the south of study area (Ba-4), the effective porous was become weaker because of dominance the dolomitization effect. In addition to developed a new effective porous zone in the middle part of Mauddud Formation. In the northern part of the region (Ba-8), the dissolution and early dolomitized processes were the dominance effects in this unit. Therefore, the effective porous zones were becoming more prevalent and influential. Accordingly, three effective porous have been distinguished in the upper part of Maudud Formation and three others in the lower part.

Downloads

Download data is not yet available.

References

Al-Zaidy A. A., Sattam M., Nasir M. E., (2013). High Resolution Sequence Stratigraphy and Reservoir Characterization of the Hartha Formation in Ahdab Oilfield. Journal of Babylon

University/ Engineering Sciences / No. (1)/ Vol.(21), pp. 37-49.

Anderson, J. H., (1985). Depositional facies and carbonate diagenesis of the downslope reefs in the Nisku Formation (U. Devonian), central Alberta, Canada. Dissertation. The University of Texas/ Austin, Texas, 393p.

Bathurst, R. G. C., (1975). Carbonate sediments and their diagenesis. Developments in Sedimentology 12. (Second Edition) Elsevier/Amsterdam, 658p.

Bellen, R. C. Van, Dunnington, H. V., Wetzel, R. and Morton, D., (1959). Lexique Stratigraphique, Interntional. Asie, Iraq, vol. 3c. 10a, 333p.

Boogs S. Jr., (2009). Petrology OF Sedimentary Rocks, second edition, Cambridge University Press, New York, 600p.

Buday, T., (1980). The Regional Geology of Iraq. Vol.1: Stratigraphy and Paleogeography. Publications of GEOSURV, Baghdad.

Burley, S.D., (1984). Patterns of diagenesis in the Sherwood Sandstone Group (Triassic), United Kingdom. Clay Minerals, 19, 403–440

Choquette P.W. and Pray L.C., (1970). Geological nomenclature and classification of porosity in sedimentary carbonate, APGB, Vol. 54, pp: 207- 250.

Douban, A. F. and Medhadi, P., (1999). Sequence Cretaceous Megasequences, Kuwait. AAPG International.

Dunham, R.J., (1962), Classification of carbonate according to depositional texture, in Ham, W.E. (ed.), Classification of carbonate rocks. AAPG Memoir 1, p.108-121.

Einsele, G., (2000). Sedimentary basins: evolution, facies, and sediment budget. Springer.792 pp.

Flugel, E. (2010) Microfacies of Carbonate Rocks, Analysis, Interpretation and Application. Springer-Verlag, Berlin, 976 p.

Flugel, E., (2004). Microfacies analysis of limestone, Translated by Christensen, K., Springer-Verlag, Berlin, 633pp.

Folk, R. L., (1962). Spectral subdivision of limestone types, in W. E. Ham, ed., Classification of Carbonate Rocks: Tulsa, OK, American Association of Petroleum Geologists Memoir 1, p. 62-84.

Folk, R.L., (1965). Some aspects of recrystallization in ancient limestone, in Pray, L.C. and Murray, R.C. (eds.), Dolomitization and limestone diagenesis: a symposium, SEPM Spec.Pub.13, p.14-48.

Ginsburg R. N., (1957). Early diagenesis and 1ithification of shallow water carbonate sediments m south Florida.In: Regional aspects of carbonate deposition: Soc. Econ. Paleontologists and Mineralogists, Spec, Publ., 5: p.80-99.

Jassim S.Z. Buday T. (2006) Tectonic Framework. In Jassim, S.Z. and Goff, J.C., 2006. Geology of Iraq. Dolin, Prague and Moravian Museum, Brno. 341pp.

Kaufman, J., Cander, H.S., Daniels, L.D., AND Meyers, W.J., (1988). Calcite cement stratigraphy and cementation history of the Burlington–Keokuk Formation (Mississippian), Illinois and Missouri: Journal of Sedimentary Petrology, v. 58, p. 312–326.

Longman, M.W., (1980). Carbonate diagenetic textures from near shore diagenetic environments. AAPG Bulletin, v.64, p.461-487.

Lucia, F.J., (2007). Carbonate Reservoir Characterization. An Integrated Approach, Second Edition. Springer Verlag Berlin, Heidelberg. 336p.

Mattes, B. W. and Mountjoy, E. W., (1980). Burialdolomitization of the UpperDevonian Miette buildup, Jasper National Park, Alberta. In: D. H. Zenger, J. B. Dunham and R. L. Ethington (Eds.),

Concepts and Models of Dolomitization. SEPM Spec. Pub. No. 28, pp. 259-297. 22. Moore, C. H., (2004). Carbonate reservoirs, porosity evaluation and diagenesis in a sequence stratigrphic framework, Developments in sedimentology55.

Moore, C.H. (1989): Carbonate diagenesis and porosity. Developments in Sedimentology, 46, 338 p.

Murray, R. C., (1960). Origin of porosity in carbonate rocks. J. Sediment. Petrol., 30: p.59- 84.

Nichols, G. (2009) Sedimentology and Stratigraphy. Blackwell Science Ltd., London, 335 p.

Roger, M. S., (2006). Stratigraphic Reservoir Characterization for Petroleum Geologists, Geophysicists and Engineers, First Edition, Elsevier, 478p.

Scholle, P. A., & Ulmer-Scholle, D. S., (2003), A Color Guide to the Petrography of Carbonate Rocks: Grains, textures, porosity, diagenesis, AAPG Memoir 77, Published by The American Association of Petroleum Geologists, Tulsa, Oklahoma, USA, 459pp.

Scholle, P. A., (1977). Chalk diagenesis and its relation to petroleum exploration: oil from chalks, a modern miracle? Am. Assoc. Petrol. Geol. Bull., 61: p.982-1009.

Summerfield, M. A., (1983). Petrography and diagenesis of silcrete from the Kalahari Basin and Cape coastal zone, southern Africa. Journal of sedimentary petrology 53: 895-909.