Shale volume and permeability of the Miocene unconsolidated turbidite sands of Bonga oil field, Niger delta, Nigeria

  • Authors

    • Inyang Namdie University of Uyo, Uyo, Akwa Ibom State, Nigeria
    • Idara Akpabio University of Uyo, Uyo, Akwa Ibom State, Nigeria
    • Agbasi Okechukwu .E.
    2017-05-16
    https://doi.org/10.14419/ijag.v5i1.7586
  • Bonga Field, Permeability, Porosity, Shale Volume, Turbidite Sand.

  • Abstract

    Bonga oil field is located 120km (75mi) southeast of the Niger Delta, Nigeria. It is a subsea type development located about 3500ft water depth and has produced over 330 mmstb of hydrocarbon till date with over 16 oil producing and water injection wells. The producing formation is the Middle to Late Miocene unconsolidated turbidite sandstones with lateral and vertical homogeneities in reservoir properties. This work, analysis the petrophysical properties of the reservoir units for the purpose of modeling the effect of shale content on permeability in the reservoir. Turbidite sandstones are identified by gamma-ray log signatures as intervals with 26-50 API, while sonic, neutron, resistivity, caliper and other log data are applied to estimate volume of shale ranging between 0.972 v/v for shale intervals and 0.0549 v/v for turbidite sands, water saturation of 0.34 v/v average in most sand intervals, porosity range from 0.010 for shale intervals to 0.49 v/v for clean sands and permeability values for the send interval 11.46 to2634mD, for intervals between 7100 to 9100 ft., Data were analyzed using the Interactive Petrophysical software that splits the whole curve into sand and shale zones and estimates among other petrophysical parameters the shale contents of the prospective zones. While Seismic data revealed reservoir thickness ranging from 25ft to over 140ft well log data within the five wells have identified sands of similar thickness and estimated average permeability of700mD. Within the sand units across the five wells, cross plots of estimated porosity, volume of shale and permeability values reveal strong dependence of permeability on shale volume and a general decrease in permeability in intervals with shale volume. It is concluded that sand units with high shale contents that are from0.500 to0.900v/v will not provide good quality reservoir in the field.

  • References

    1. [1] Bonga Field-Wikipedia, the free Encyclopedia. http://www.wikipedia.org.

      [2] Gaffney, Cline and Associates (2014),’’West Africa, Deep Water Nigeria: Definition of Stratigraphic Plays’’ Royal Institution.

      [3] Selly, R.C. (1988) Applied Sedimentology: Academic Press London.

      [4] Kurniawan, A. Kenzie, J.M.Putri, J.A (2009) General Dictionary of Geology: Environmental Geographic Student Association.

      [5] Abriel, W.L (2008) Reservoir Geophysics: Applications. Distinguish Instructor Series No. 11, EAGE. https://doi.org/10.1190/1.9781560801634.

      [6] Bellingham, P. Connors, C. Harworth, R. Radovich, B and Danforth, A. (2014) Deep Water Niger Delta: An Unexplored World-Class Petroleum Province. ION Geophysical Vol.11, No.5.

      [7] N. J. Inyang, E. E. Okwueze and O. E. Agbasi, (2015), Detection of Gas Sands in the Niger Delta by Estimation of Poisson’s Dampening-Factor (PDF) Using Wireline Log Data, Geosciences, p-ISSN: 2163-1697, e-ISSN: 2163-1719, 2015; 5(1): 46-51, doi:10.5923/j.geo.20150501.06.

      [8] Short, K.C and Stauble, A.J (1967) Outline of Geology of Niger Delta: AAPG Bulletin, 51:761-770

      [9] I. Akpabio, J .C. Ibuot, O. E. Agbasi and O.T. Ojo, (2014), Petrophysical Characterization of eight wells from Wire-line Logs, Niger Delta Nigeria. Asian Journal of Applied Science, ISSN 2521 - 0893, volume 02, Issue 02, 105 -109.

      [10] Kulke, H. (1995) Nigeria, In H, Kulke. (Ed.) Regional Petroleum Geology of the World. Part II: Africa, America, Australia, and Antarctica: Berlin, Gerbrunder Borntragaer, p. 143-172.

      [11] O. E. Agbasi, N. Inyang and J. Ibout, (2013), Estimation of Water Saturation in Niger Delta Nigeria Using Wire-Line logs. IOSR, Journal of Applied Physics (IOSR-JAP). e-ISSN: 2278 – 4861, volume 3, issue 4(2013) pp.66 -71. www.iosrjournals.org.

      [12] Ubong E. Essien, Akaninyene. O. Akankpo and Okechukwu. E. Agbasi (2017). Evaluation of Reservoir’s Petrophysical Parameters, Niger Delta, Nigeria. International Journal of Advanced Geosciences, 5 (1) (2017) 19-25. https://doi.org/10.14419/ijag.v5i1.7456.

      [13] O. E. Agbasi, A. O. Akankpo and U. E. Essien (2017).Estimation of Reservoir Potentials of Two Wells in Niger Delta Region, Nigeria. Journal of Geosciences and Geomatics, 2017, Vol. 5, No. 2, 87-95.

      [14] Mode, A.W and Anyiam, A.O (2007) Reservoir Characterization: Implications from Geophysical Data of ‘’Paradise-Field’’ Niger Delta, Nigeria.

      [15] Starcher, P (1995) Present Understanding of the Niger Delta Hydrocarbon Babitat: Shell Development Company of Nigeria Ltd, Warri.

      [16] Wyllie, M.R.J. Gregory, A.R and Gardner, L.W (1956) Elastic Wave Velocities in Heterogeneous and Porous Media. Geophysics 2(1):41-70. http://dx.doi.org/10.1190/1.438217.

      [17] Akankpo, A.O., Umoren E.B., Agbasi O.E., (2015). Porosity Estimation Using Wire-Line Log to Depth in Niger Delta, Nigeria. IOSR Journal of Applied Geology and Geophysics (IOSR-JAGG) e-ISSN: 2321–0990, p-ISSN: 2321–0982.Volume 3, Issue 4 Ver. II (Jul - Aug. 2015), PP 31-38 www.iosrjournals.org.

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  • How to Cite

    Namdie, I., Akpabio, I., & Okechukwu .E., A. (2017). Shale volume and permeability of the Miocene unconsolidated turbidite sands of Bonga oil field, Niger delta, Nigeria. International Journal of Advanced Geosciences, 5(1), 37-45. https://doi.org/10.14419/ijag.v5i1.7586

    Received date: 2017-04-13

    Accepted date: 2017-05-12

    Published date: 2017-05-16