Apparent water resistivity (Rwa) and porosity exponent (m) were delineated using Pickett’s plot in Miocene, unconsolidated sandstone reservoirs of the Niger Delta Region. Quick log analysis was conducted using porosity (neutron-density-sonic) log lithology log and saturation (resistivity) log to delineate the reservoirs. The gamma values reported in this study varied from 40.00 to 45.91 gAPI indicating a spectrum of clean sand and with the resistivity range of 3.56–17.46 Ωm, the neutron density cross-over shows that the reservoirs are an Oil–Gas contact reservoir. The reservoir net pay range is between 18.5 ft and 96 ft, and it is clear that the reservoirs are suitable for economic production. Again, a linear association between porosity and porosity exponents has been developed as a decrease in porosity values will result in a decrease in porosity exponents. The measured values of apparent water resistivity in the study area were 0.208 Ωm, with the porosity exponent varying from 2.08 to 2.43 (representing variance from the theoretical value of 2 of 4 to 21.5%). These values (estimated from the Pickett plot may be a more accurate depiction of in situ condition) would aid in a better and more effective estimation of the formation factor in the area of study rather than incorporating theoretical constants from Archie’s equation.
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Adebayo, A. R., Al-Yousef, H. Y., & Mahmoud, M. (2014). Determination of Archie’s saturation exponent for CO2 sequestration in carbonate reservoirs Society of Petroleum Engineers. #172354SPE. Nigeria Annual International Conference and Exhibition (Lagos, Nigeria, 5–7 August).
Agbasi, O. E., Akankpo, A. O., & Essien, U. E. (2017). Estimation of reservoir potentials of two wells in Niger Delta, region Nigeria. Journal of Geosciences and Geomatics. https://doi.org/10.12691/jgg-5-2-5.
Agbasi, O. E., Igboekwe, M., Chukwu, G., & Etuk, S. E. (2018). Discrimination of pore fluid and lithology of a well in X field, Niger, Delta Nigeria. Arabian Journal of Geoscience. https://doi.org/10.1007/s12517-018-3610-7.
Agbasi, O. E., Sen, S., Inyang, N. J., & Etuk, S. E. (2021). Assessment of pore pressure, wellbore failure and reservoir stability in the Gabo field Niger Delta, Nigeria. Implications for drilling and reservoir management. Journal of African Earth Sciences. https://doi.org/10.1016/j.jafrearsci.2020.104038.
Aguilera, R. (2001). Incorporating capillary pressure, pore throat aperture radii, height above free-water table and Winland r35 values on Pickett plots. Bulletin of the American Association of Petroleum Geologists. https://doi.org/10.1306/61EEDB5C-173E-11D7-8645000102C1865D.
Aigbedion, I. (2007). Reservoir Fluid Differentiation case study from the Oredo Field. International Journal of Physical Sciences. https://doi.org/10.5897/IJPS.9000487.
Ara, T. S., Talabani, S., Vaziri, H. H., & Islam, M. R. (2001). In-depth investigation of the validity of the Archie equation in carbonate rocks. Society of Petroleum Engineers. https://doi.org/10.2118/67204-MS.
Archie, G. E. (1942). The electrical resistivity logs as an aid in determining some reservoir characteristics. Trans. https://doi.org/10.2118/942054-G.
Archie, G. E. (1952). Classification of carbonate reservoir rocks and petrophysical considerations. Bulletin of the American Association of Petroleum Geologists. https://doi.org/10.1306/3D9343F7-16B1-11D7-8645000102C1865D.
Avbovbo, A. A., & Ayoola, O. (1981). Petroleum prospects of the Southern Nigeria’s Anambra Basin. Oil Gas Journal, 79, 334–347.
Bassiouni, Z. (1994). Theory, measurement, and interpretation of well logs. Society of Petroleum Engineers.
Carothers, J. E. (1968). A statistical study of the formation factor relation to porosity. Log Analyst, 9(5), 13–20.
Ellis, D. V., & Singer, J. M. (2007). Well logging for earth scientists (2nd ed.). Springer.
Falebita, B. (2003). Deep drilling in the Niger Delta. Nape Bulletin, 10(1), 1–5.
Farid, M. F., Arns, J. Y., Pinczewski, W. V., & Arns, C. H. (2016). Experimental and numerical investigation on stress dependence of sandstone electrical properties and deviations from Archie’s law. SPE Annual Technical Conference and Exhibition. https://doi.org/10.2118/181484-MS.
Glover, P. W. J. (2009). What is the cementation exponent? A new interpretation. The Leading Edge. https://doi.org/10.1190/1.3064150.
Gomez-Rivero, O. (1977). Some considerations about the possible use of the parameters a and m as a formation evaluation tool through well logs. In: SPWLA 18th Annual Logging Symposium, Houston, Texas.
Haddad, S., Najimi, S., Zulkipli, S. N. F., Sinnappu, S., Johan, Z. J., Kyi, K. K., Wa, W. W., & Tan, W. (2013). Clastic and carbonate formation evaluation case study: East Asia Society of Petroleum Engineers. SPE Western Regional and AAPG Pacific Section Meeting Joint Technical Conference. https://doi.org/10.2118/165370-MS.
Hamada, G. M., Al-Awad, M. N. J., & Almalik, M. S. (2001). Log Evaluation of low-resistivity sandstone reservoirs. SPE Permian Basin Oil and Gas Recovery Conference. https://doi.org/10.2118/70040-MS.
Haro, C. (2009). The equations archie forgot: Anisotropy of the rocks. SPE Annual Technical Conference and Exhibition. https://doi.org/10.2118/123913-MS.
Hill, H. J., & Milburn, J. D. (1956). Effect of clay and water salinity on electrochemical behaviour of reservoir rocks. Transactions of the AIME. https://doi.org/10.2118/532-G.
Inyang, N. J., Akpabio, O. I., & Agbasi, O. E. (2017). Shale volume and permeability of the miocene unconsolidated turbidite sand of Bonga oil field Niger, Delta Nigeria. International Journal of Advanced Geoscience. https://doi.org/10.14419/ijag.v5il.7586.
Jardine, D., & Wilshart, J. W. (1982). Carbonate reservoir description SPE #10010. International Petroleum Exhibition and Technical Symposium of the Society of Petroleum Engineers. https://doi.org/10.2118/10010-MS.
Jorden, J.R. (1971). Goals for formation evaluation. Society of Petroleum Engineers. Journal of Petroleum Technology. https://doi.org/10.2118/3269-PA.
Leandro, H., & Ivan, M. (2015). The impact of Archie’s parameters in the calculation of water saturation for carbonate reservoir, Campos Basin, Brazil SEG-2015-5915007SEG Annual Meeting (New Orleans, Louisiana, 18–23 October).
Li, G. R., Guo, Q. Y., Shi, Y. J., & Li, C. H. (2006). Identification of high gamma ray reservoir in Ordos Basin. Well Logging Technology, 30(6), 511–515.
Magbagbeola, O. A., & Willis, B. J. (2007). Sequence stratigraphic and syndepositional deformation of the Agbada Formation Robertkiri field Niger Delta, Nigeria. Bulletin of the American Association of Petroleum Geologists. https://doi.org/10.1306/02050705150.
MazinM. A. (2006). Using Modified CORIBAND Technique to Evaluate Carbonate Reservoirs in East Baghdad Oil Field, M.Sc. Thesis, University of Baghdad.
Morgan, W. B., & Pirson, S. J. (1964). The effect of fractional wettability on the Archie saturation exponent. Society of Petrophysicists and Well Log Analysts-1964-B, SPWLA 5th Annual Logging Symposium (Midland, Texas, 13–15 May).
Panda, A., Darous, C., Al-Kindi, Z., Akram, A., & Kriplani, S. (2016). A specific approach to petrophysical evaluation in a complex carbonate reservoir SPE# 183097Abu Dhabi. International Petroleum Exhibition and Conference. https://doi.org/10.2118/183097-ms.
Pickett, G. R. (1966). A review of current techniques for determination of water saturation from logs. Journal of Petroleum Technology. https://doi.org/10.2118/1446-PA.
Pickett, G.R., (1973). Pattern recognition as a means of formation evaluation. The Log Analyst, 14(4), 3–11.
Porter, C. R., & Carothers, J. E. (1970). Formation factor porosity relationship derived from well log data. Society of petrophysicists and Well Log Analysts. In: 11th Annual Logging Symposium, Los Angeles, May 3–6.
Short, K. C., & Stauble, A. J. (1967). Outline of geology of Niger Delta. American Association of Petroleum Geologists Bulletin. https://doi.org/10.1306/5D25C0CF-16C1-11D7-8645000102C1865D.
Tiab, D., & Donaldson, E. C. (2012). Petrophysics: Theory and practice of measuring reservoir rock and fluid transport properties (3rd ed.). Gulf Professional Publishing.
Timur, A., Hempkins, W. B., & Worthington, A. E. (1972). Porosity and pressure dependence of formation resistivity factor for sandstones. In: Canadian Well Logging Society 4th Formation Evaluation Symposium, Calgary, Canada, May 9–10.
Winsauer, W. O., Shearin, H., Masson, P., & Williams, M. (1952). Resistivity of brine-saturated sands in relation to pore geometry. Association of Petroleum Geologists Bulletin. https://doi.org/10.1306/3D9343F4-16B1-11D7-8645000102C1865D.
Worthington, P. (2011). The petrophysics of problematic reservoirs. Journal of Petroleum Technology. https://doi.org/10.2118/144688-JPT.
Yu, Z. F., Cheng, R. H., Zhao, X. Q., Sun, F. X., Xu, Z. J., & Shen, Y. J. (2012). Genesis and identification of high gamma sandstone in the first member of of Nantun formation of Wunan depression in Hailar Basin. Journal of China University of Petroleum. https://doi.org/10.3969/j.issn.1673-5005.2012.03.012.
Zhang, X. L., Feng, Q., Sun, P., & Li, W. (2010). Characteristics of high gamma ray reservoir of Yanchang formation in Ordos Basin. Chinese Journal of Geophysics. https://doi.org/10.3969/j.issa.0001-5733.2010.01.023.
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Igboekwe, M.U., Agbasi, O.E., Chukwu, G.U. et al. Delineation of apparent water resistivity and porosity exponent of the Miocene unconsolidated sandstone reservoir of coastal swamp depobelt, Niger Delta, Nigeria. J. Sediment. Environ. (2021). https://doi.org/10.1007/s43217-021-00068-1
- Archie’s equation
- Formation factor
- Pickett’s plot