Reservoir evaluation and hydrocarbon play assessment in a Niger Delta field

نوع مقاله : مقاله پژوهشی‌

نویسندگان

1 Assistant Professor, Department of Geology and Geophysics, Alex Ekwueme Federal University, Ndufu Alike, Nigeria

2 Assistant Professor, Department of Geology, Gregory University, Uturu Abia State, Nigeria

3 Associate Professor, Department of Geology and Geophysics, Alex Ekwueme Federal University, Ndufu Alike, Nigeria

چکیده

Amidst the blend of trepidation about dwindling petroleum reserves, a latent frenzy towards improving reserves worldwide, and the ironical call for replacement of fossil fuels, the need still persists, to leverage on legacy data and increasing technological advantages to
re-characterize existing fields for optimal reserve recovery. Reservoir evaluation and
hydrocarbon play assessment of a typical Niger delta field has been carried out in this
research work. This involved delineation of reservoir rocks, characterizations of the fluid within the reservoir, and assessment of the structural relations of the seal, source, and trap (Play Type) in the study location. By inspection of the signatures of a suit of petrophysical logs (comprising of resistivity, gamma ray, shale volume, and density), the HD2000
reservoir was delineated. The reservoir is sandwiched between two impermeable shale beds (seals/caps) bordering the top and bottom of the reservoir. Using Lambda-Rho, Mu-Rho,
P-Impedance, Vp/Vs Ratio, and porosity, petrophysical cross plot analyses was carried out. Advanced post-stack 3-D acoustic impedance inversion yielded petrophysical attribute slices which helped to validate the observations in the cross plots. Results showed that the wells cut through zones of low values of P- Impedance, Mu-Rho, Lambda-Rho, and Vp/Vs ratio, corresponding to hydrocarbon saturated sands. Event time structure maps at both horizons and a seismicsection showing faults, fractures, and an anticline structural trend, confirmed that the play type is a fault and fracture infested rollover anticline, which combines with the delineated seals/caps at the top and bottom of the reservoir to form a structural trap for
hydrocarbon within the reservoir. These observations correspond to the characteristics of plays in the oil rich belt of the Niger delta petroleum field, where rollover anticlines in front of growth faults form the main objectives of oil exploration.
 

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Reservoir evaluation and hydrocarbon play assessment in a Niger Delta field

نویسندگان [English]

  • Azuoko George-Best 1
  • Usman Ayatu Ojonugwa 1
  • Emmanuel Onyeka Ezim 2
  • Ekwe Amobi Chigozie 3
  • Ema Michael Abraham 1
1 Assistant Professor, Department of Geology and Geophysics, Alex Ekwueme Federal University, Ndufu Alike, Nigeria
2 Assistant Professor, Department of Geology, Gregory University, Uturu Abia State, Nigeria
3 Associate Professor, Department of Geology and Geophysics, Alex Ekwueme Federal University, Ndufu Alike, Nigeria
چکیده [English]

Amidst the blend of trepidation about dwindling petroleum reserves, a latent frenzy towards improving reserves worldwide, and the ironical call for replacement of fossil fuels, the need still persists, to leverage on legacy data and increasing technological advantages to
re-characterize existing fields for optimal reserve recovery. Reservoir evaluation and
hydrocarbon play assessment of a typical Niger delta field has been carried out in this
research work. This involved delineation of reservoir rocks, characterizations of the fluid within the reservoir, and assessment of the structural relations of the seal, source, and trap (Play Type) in the study location. By inspection of the signatures of a suit of petrophysical logs (comprising of resistivity, gamma ray, shale volume, and density), the HD2000
reservoir was delineated. The reservoir is sandwiched between two impermeable shale beds (seals/caps) bordering the top and bottom of the reservoir. Using Lambda-Rho, Mu-Rho,
P-Impedance, Vp/Vs Ratio, and porosity, petrophysical cross plot analyses was carried out. Advanced post-stack 3-D acoustic impedance inversion yielded petrophysical attribute slices which helped to validate the observations in the cross plots. Results showed that the wells cut through zones of low values of P- Impedance, Mu-Rho, Lambda-Rho, and Vp/Vs ratio, corresponding to hydrocarbon saturated sands. Event time structure maps at both horizons and a seismicsection showing faults, fractures, and an anticline structural trend, confirmed that the play type is a fault and fracture infested rollover anticline, which combines with the delineated seals/caps at the top and bottom of the reservoir to form a structural trap for
hydrocarbon within the reservoir. These observations correspond to the characteristics of plays in the oil rich belt of the Niger delta petroleum field, where rollover anticlines in front of growth faults form the main objectives of oil exploration.
 

کلیدواژه‌ها [English]

  • Reservoir
  • play
  • rock properties/attributes
  • petrophysical volumes

مراجع

Azuoko, G-B., Ehirim, C. N., Ebeniro J. O., and Uraechu D. N. 2017, “Multiples in Onshore Niger Delta from 3D Prestack Seismic Data” International Journal of Physical Sciences”, Vol. 12, Issue 1, pp. 1–7, 16th January, 2017 (DOI: 10.5897/IJPS2016.4558)
Azuoko, G-B., 2016, “Multiple Generators in Onshore Niger Delta”, International Journal of Scientific and Engineering Research, Vol. 7, Issue 10, pp. 368 – 372, 10th October, 2016
Azuoko, G-B., Ekwe, A. C., Amulu, E. N., Usman, A. O., Omonona, O. V., Eluwa, N. N. and Kufre, U. I. 2021, Rock Property Cross-Plot Analysis And Post-Stack Acoustic Impedance Inversion for Optimal Reservoir Characterization In "Alpha" Field, Onshore Niger Delta Basin. Presented at the SPE Nigeria Annual International Conference and Exhibition, Lagos, Nigeria, August 2021. SPE-208252-MS https://doi.org/10.2118/208252-MS . Published:August 02 2021
Bassey, N., 1996, Prospect generation, Basic concepts and definition: Schlumberger Ltd.
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Edwards, J. D. and Santogrossi, P. A. 1990, Summary and conclusions, in, Edwards, J. D. and Santogrossi, P. A. eds., Divergent/passive Margin Basins, AAPG Memoir 48: Tulsa, American Association of Petroleum Geologists, P. 239-248.
Ejedawe, J. E., 1981, Patterns of incidence of oil reserves in Niger Delta Basin: American Association of Petroleum Geologists, v. 65, p. 1574-1585.
Ekwe, A. C., Onuoha K. M., Osayande N., 2012, Fluid and Lithology Discrimination Using Rock Physics Modelling and Lambdamurho Inversion: An example from Onshore Nigeria: Search and Discovery Article #40865
Evamy, B. D., Haremboure, J., Kamerling, P., Knaap, W. A., Molloy, F. A. and Rowlands, P. H., 1978, Hydrocarbon habitat of Tertiary Niger Delta: American Association of Petroleum Geologists Bulletin, v. 62, p. 277-298.
Gabor, T., Hussein, H., Bernhard, N., 2010, “Play Types and Hydrocarbon Potential of Deep-Water NW Egypt”: AAPG Annual Convention Exhibition, Denver, Colorado, USA.
Huff, K. F., 1980, Frontiers of World Exploration, in: Facts and Principles of World Petroleum Geology, Miall, A.D. (ed), Canadian Society of Petroleum Geology, Memoir #6, Calgary, Alberta, Canada, p. 343-362.
Ibe, A. A., Oyewole, T. E, 2018, Hydrocarbon play assessment of X-field in an onshore Niger Delta, Nigeria. Springer Journal of Petroleum Exploration and Production Technology (PEPT), DOI: org/10.1007/s13202-018-0497-5
Kjempeurd, A., 2005, Resource Assessment: CNPA.
Osisanya, W. O., Alile, O. M., Eze, S. U., Ibitoye, T. A. and Oyanameh, O. E, 2021, Hydrocarbon Play Assessment of “Oswil” Field, Onshore Niger Delta
Region Journal of Geological Research 3(1), DOI: 10.30564/jgr.v3i1.2783
Pratap, V. and Sonare, S. C., 2005, “Insights on Olpad Formation: -Assessment of Hydrocarbon Play Types in North Cambay Basin, India”: ONGC, Meshna.
Weber, K. J. 1987, Hydrocarbon distribution patterns in Nigerian growth fault structures controlled by structural style and stratigraphy: Journal of Petroleum Science and Engineering, v. 1, p. 91-104.
مجله ژئوفیزیک ایران
دوره 16، شماره 4
بهمن 1401
صفحه 113-122

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