Petrophysical analysis of “explorer†wells using well log and core data(a case study of “explorer†field, offshore Niger Delta, Nigeria)

  • Authors

    • Abe J. Sunday Federal University of Technology Akure
    • Lurogho S. Ayoleyi Federal University of Technology Akure
    2020-10-22
    https://doi.org/10.14419/ijag.v8i2.31114
  • Petrophysics, Correlation, Regression, Niger Delta, Reservoirs, Characterization, Hydrocarbon and Saturation.

  • Abstract

    Reservoir characterization involves computing various petrophysical parameters and defining them in terms of their quantity and quality so as to ascertain the yield of the reservoir. Petrophysical well log and core data were integrated to analyze the reservoir characteristics of Explorer field, Offshore, Niger Delta using three wells. The study entails determination of the lithology, shale volume (Vsh), porosity (Φ), permeability (K), fluid saturation and cross plotting of petrophysical and core values at specific intervals to know their level of correlation. The analysis identified twelve hydrocarbon-bearing reservoir from three different wells. Average permeability value of the reservoir is 20, 0140md while porosity value range between 18% to 39%. Fluid type defined in the reservoirs on the basis of neutron/density log signature were basically water, oil and gas, low water saturation values ranging from 2.9% to 46% in Explorer wells indicate high hydrocarbon saturation. The Pearson Correlation Coefficient and Regression Equation gave a significant relationship between petrophysical derived data and core data. Scatter plot of petrophysical gamma ray values versus core gamma ray values gave an approximate linear relationship with correlation coefficient values of 0.6642, 0.9831 and 0.3261. Crossplot of petrophysical density values and core density values revealed that there is a strong linear relationship between the two data set with correlation coefficient values of 0.7581, 0.9872 and 0.3557, and the regression equation confirmed the relationship between the two data set. Also the scatter plot of petrophysical porosity density values versus core porosity density values revealed a strong linear relationship between the two data set with correlation coefficient values of 0.7608 and 0.9849, the regression equation confirmed this also. Crossplot of petrophysical porosity density values versus core porosity density values in Well 3 gave a very weak correlation coefficient values of 0.3261 and 0.3557 with a negative slope. The petrophysical properties of the reservoirs in Explorer Well showed that they contain hydrocarbon in commercial quantity and the cross plot of the petrophysical and core values showed direct relationship in most of the wells.

     

     

  • References

    1. [1] Adaeze, I., Ulasi, S., Onyekuru, O., and Julian, C.J. (2012): Petrophysical evaluation of Uzek well using well log and core data, offshore Depobelt, Niger Delta, Nigeria: Pelagia Research Library.

      [2] Google Map (1994): Google map of Nigeria showing the Niger Delta. Retrieved from https://maps.google.com/maps?q=map+of+the+niger+delta&ie=UTF8&hq=&hnear=Niger+Delta&ll=5.670651,7.745361&spn=3.164564,5.410767&t=m&z=8&vpsrc=6&ei=ZiLHUveKH8zD8AOzwYGQAw&pw=2/.

      [3] H. Doust and O. Omatsola, Niger delta. In: Edwards, J., Santagrossi, P. (Eds.), Divergent Passive Margins. American Association of Petroleum Geologists, Memoir 48, pp. 191-248, 1990.

      [4] K.C. Short and A.J. Stauble, “Outline of geology of Niger Delta,†American Association of Petroleum Geologists Bulletin, vol. 51, pp. 761-779, 1967.https://doi.org/10.1306/5D25C0CF-16C1-11D7-8645000102C1865D.

      [5] E.J. Frankl and E.A. Cordy, “The Niger Delta Oil Province: Recent developments onshore and offshore,†Proceedings ofSeventh World Petroleum Congress, Mexico City, pp. 195-209, 1967.https://doi.org/10.1306/5D25B843-16C1-11D7-8645000102C1865D.

      [6] A. Avbovbo, “Tertiary lithostratigraphy of Niger Delta,†American Association of Petroleum Geologists Bulletin, vol. 62, pp. 295-300, 1978.https://doi.org/10.1306/C1EA482E-16C9-11D7-8645000102C1865D.

      [7] K.J. Weber, “Hydrocarbon Distribution Pattern in Nigerian growth fault structures controlled by structural style and stratigraphy,†Journal of Petroleum Science and Engineering, 1, pp. 1-12, 1987.https://doi.org/10.1016/0920-4105(87)90001-5.

      [8] A. Dresser, “Log interpretation charts,†Houston Dresser Industries, Inc. pp. 107, 1979.

  • Downloads

  • How to Cite

    J. Sunday, A., & S. Ayoleyi, L. (2020). Petrophysical analysis of “explorer” wells using well log and core data(a case study of “explorer” field, offshore Niger Delta, Nigeria). International Journal of Advanced Geosciences, 8(2), 219-230. https://doi.org/10.14419/ijag.v8i2.31114

    Received date: 2020-08-27

    Accepted date: 2020-10-03

    Published date: 2020-10-22