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Subsurface Characterization Using Downhole Refraction Survey: A Case Study of the Niger Delta

Received: 15 January 2024     Accepted: 26 January 2024     Published: 7 March 2024
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Abstract

This study addresses the critical role of downhole refraction as a method for assessing subsurface characteristics, particularly in areas facing challenges such as ground roll issues and weak reflection signals during seismic data acquisition. Focused on the Agudama, Kenfa, and Yenegwe settlements in the Niger Delta region, where frequent engineering structure collapses occur, the research aims to understand the depth and velocity of unconsolidated zones through downhole refraction. The study emphasizes the limitations of relying solely on uphole refraction and highlights the necessity of downhole methods for accurate velocity determination. The research employs various techniques, including borehole drilling, velocity measurements, and seismic pulse generation. The study's primary objectives include investigating the causes of engineering structure failures, proposing geophysical solutions, and contributing valuable insights into the geological context of the Niger Delta region. The fieldwork involved a comprehensive approach, combining reconnaissance surveys, downhole refraction studies, and the use of specialized equipment such as a Geometrics Stratavisor NZXP seismograph and explosives for seismic sources. The results of the downhole refraction survey reveal a double-layer velocity model in the research areas, indicating variations in weathered or unconsolidated layer thickness and velocities. The study establishes a relationship between elevation, weathered layer thickness, and velocities in both weathered and consolidated layers, offering valuable information for engineering considerations. The research concludes that the downhole refraction method is crucial for evaluating weathered strata properties and provides cost-effective subsurface information. The study recommends drilling below the weathered zone for seismic energy source placement, excavation depths for stable structures, and future investigations focusing on closely spaced data points and additional soil properties. These recommendations aim to enhance the safety and durability of structures in the study area, contributing to the understanding and mitigation of engineering structure failures in the Niger Delta region.

Published in Engineering and Applied Sciences (Volume 9, Issue 1)
DOI 10.11648/j.eas.20240901.11
Page(s) 1-13
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Downhole Survey, Weathered Layer, Refraction Seismic, Drilling, Seismic Energy

References
[1] Agoha CC, Opara AI, Okereke CN, Onwubuariri CN, Emberga TT, Inyang GE, Ugwuegbu IE, Chilaka JC (2015) Weathered layer determination and its effects on engineering structures: case study of parts of the Niger delta. World Environ Eng 3(2): 40–51.
[2] Ajani OO, Fajemiroye JA, Odumosu OA (2013) Study of nearsurface layers of Omerelu area using low velocity layer (LVL) method. Int J Dev Sci 2(1): 131–139.
[3] Hoover, H., Jr., and Schaeffer, H. C., 1942, System for making weathering corrections: United States Patent 2 276 306; (abstract): Geophysics, 7, 323.
[4] Sheriff, R. E., 1991, Encyclopedic Dictionary of Exploration Geophysics: Soc. Expl. Geophys.
[5] Anomoharan O (2014) Downhole seismic refraction survey Of weathered layer characteristics in Escravos Nigeria. Am J Appl Sci 11(3): 371–380.
[6] Waldhauser F, Hypo D (2001) A computer program to compute double difference earthquake location, U. S. Geol. Surv. Open-file report 01 -113.
[7] Telford WM, Geldart LP, Sheriff RE (1990) Applied Geophysics, 2nd edn. Cambridge University Press.
[8] Klett TR, Ahlbrandt TS, Schmoker JW, Dolton JL (1997) Ranking of the world’s oil and gas provinces by known petroleum volumes. U. S. Geological Survey Open-file Report-97–463, CD-ROM.
[9] Ejedawe JE (1981) Patterns of incidence of oil reserves in Niger Delta Basin. American Association of Petroleum Geologists (AAPG), vol. 65.
[10] Doust H, Omatsola E (1990) Niger delta. In: Edwards JD, Santogrossi PA (eds) Divergent/passive margin basins AAPG Memoir 48. American Association of Petroleum Geologists.
[11] Kulke H (1995) Nigeria. In: Kulke H (ed) Regional petroleum geology of the world. Part II: Africa, America, Australia and Antarctica. Borntraeger, Berlin, Gebriider, pp 143–172.
[12] Hospers J (1965) Gravity field and structure of the Niger delta, Nigeria, West Africa. Geol Soc Am Bull 76: 407–422.
[13] Kaplan A, Lusser CU, Norton IO (1994) Tectonic map of the world, panel 10: Tulsa. American Association of Petroleum Geologists, scale 1: 10,000,000.
[14] Weber KJ, Daukoru EM (1975) Petroleum Geology of the Niger Delta. In: Proceedings of the ninth World Petroleum Congress, vol 2. Geology Applied Science Publishers, Ltd, London.
[15] Onwubuariri CN, Al-Naimi LS, Ijeh BI, Mgbeojedo TI, Igboekwe MU, Nnanna LA (2021) Investigation of geophysical challenges in land seismic data acquisition in Nigeria: case study of parts of the niger delta region. J Pet Explor Prod Technol 11: 587–599.
[16] Chiemeke CC, Aboh HO (2012) Delineation of aquiferous layers within the basement complex using joint inversion of seismic refraction tomography and high resolution 3D seismic reflection survey. Arch Appld Sci Res 4: 400–405.
Cite This Article
  • APA Style

    Onwubuariri, C. N., Anakwuba, E. K., Agoha, C. C., Egwuonwu, E., Ugochukwu, J., et al. (2024). Subsurface Characterization Using Downhole Refraction Survey: A Case Study of the Niger Delta. Engineering and Applied Sciences, 9(1), 1-13. https://doi.org/10.11648/j.eas.20240901.11

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    ACS Style

    Onwubuariri, C. N.; Anakwuba, E. K.; Agoha, C. C.; Egwuonwu, E.; Ugochukwu, J., et al. Subsurface Characterization Using Downhole Refraction Survey: A Case Study of the Niger Delta. Eng. Appl. Sci. 2024, 9(1), 1-13. doi: 10.11648/j.eas.20240901.11

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    AMA Style

    Onwubuariri CN, Anakwuba EK, Agoha CC, Egwuonwu E, Ugochukwu J, et al. Subsurface Characterization Using Downhole Refraction Survey: A Case Study of the Niger Delta. Eng Appl Sci. 2024;9(1):1-13. doi: 10.11648/j.eas.20240901.11

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      author = {Chukwuebuka Nnamdi Onwubuariri and Emmanuel Kenechukwu Anakwuba and Chidiebere Charles Agoha and Emmanuel Egwuonwu and Joseph Ugochukwu and Lawson-Jack Osaki and Tochukwu Innocent Mgbeojedo},
      title = {Subsurface Characterization Using Downhole Refraction Survey: A Case Study of the Niger Delta},
      journal = {Engineering and Applied Sciences},
      volume = {9},
      number = {1},
      pages = {1-13},
      doi = {10.11648/j.eas.20240901.11},
      url = {https://doi.org/10.11648/j.eas.20240901.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.eas.20240901.11},
      abstract = {This study addresses the critical role of downhole refraction as a method for assessing subsurface characteristics, particularly in areas facing challenges such as ground roll issues and weak reflection signals during seismic data acquisition. Focused on the Agudama, Kenfa, and Yenegwe settlements in the Niger Delta region, where frequent engineering structure collapses occur, the research aims to understand the depth and velocity of unconsolidated zones through downhole refraction. The study emphasizes the limitations of relying solely on uphole refraction and highlights the necessity of downhole methods for accurate velocity determination. The research employs various techniques, including borehole drilling, velocity measurements, and seismic pulse generation. The study's primary objectives include investigating the causes of engineering structure failures, proposing geophysical solutions, and contributing valuable insights into the geological context of the Niger Delta region. The fieldwork involved a comprehensive approach, combining reconnaissance surveys, downhole refraction studies, and the use of specialized equipment such as a Geometrics Stratavisor NZXP seismograph and explosives for seismic sources. The results of the downhole refraction survey reveal a double-layer velocity model in the research areas, indicating variations in weathered or unconsolidated layer thickness and velocities. The study establishes a relationship between elevation, weathered layer thickness, and velocities in both weathered and consolidated layers, offering valuable information for engineering considerations. The research concludes that the downhole refraction method is crucial for evaluating weathered strata properties and provides cost-effective subsurface information. The study recommends drilling below the weathered zone for seismic energy source placement, excavation depths for stable structures, and future investigations focusing on closely spaced data points and additional soil properties. These recommendations aim to enhance the safety and durability of structures in the study area, contributing to the understanding and mitigation of engineering structure failures in the Niger Delta region.
    },
     year = {2024}
    }
    

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    AU  - Chukwuebuka Nnamdi Onwubuariri
    AU  - Emmanuel Kenechukwu Anakwuba
    AU  - Chidiebere Charles Agoha
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    AU  - Joseph Ugochukwu
    AU  - Lawson-Jack Osaki
    AU  - Tochukwu Innocent Mgbeojedo
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    N1  - https://doi.org/10.11648/j.eas.20240901.11
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    JO  - Engineering and Applied Sciences
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    UR  - https://doi.org/10.11648/j.eas.20240901.11
    AB  - This study addresses the critical role of downhole refraction as a method for assessing subsurface characteristics, particularly in areas facing challenges such as ground roll issues and weak reflection signals during seismic data acquisition. Focused on the Agudama, Kenfa, and Yenegwe settlements in the Niger Delta region, where frequent engineering structure collapses occur, the research aims to understand the depth and velocity of unconsolidated zones through downhole refraction. The study emphasizes the limitations of relying solely on uphole refraction and highlights the necessity of downhole methods for accurate velocity determination. The research employs various techniques, including borehole drilling, velocity measurements, and seismic pulse generation. The study's primary objectives include investigating the causes of engineering structure failures, proposing geophysical solutions, and contributing valuable insights into the geological context of the Niger Delta region. The fieldwork involved a comprehensive approach, combining reconnaissance surveys, downhole refraction studies, and the use of specialized equipment such as a Geometrics Stratavisor NZXP seismograph and explosives for seismic sources. The results of the downhole refraction survey reveal a double-layer velocity model in the research areas, indicating variations in weathered or unconsolidated layer thickness and velocities. The study establishes a relationship between elevation, weathered layer thickness, and velocities in both weathered and consolidated layers, offering valuable information for engineering considerations. The research concludes that the downhole refraction method is crucial for evaluating weathered strata properties and provides cost-effective subsurface information. The study recommends drilling below the weathered zone for seismic energy source placement, excavation depths for stable structures, and future investigations focusing on closely spaced data points and additional soil properties. These recommendations aim to enhance the safety and durability of structures in the study area, contributing to the understanding and mitigation of engineering structure failures in the Niger Delta region.
    
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Author Information
  • Department of Physics, Michael Okpara University of Agriculture, Umudike, Nigeria; Department of Geophysics, Nnamdi Azikiwe University, Awka, Nigeria

  • Department of Geophysics, Nnamdi Azikiwe University, Awka, Nigeria

  • Department of Geology, Federal University of Technology, Owerri, Nigeria

  • Department of Physics, Michael Okpara University of Agriculture, Umudike, Nigeria

  • Department of Physics, Michael Okpara University of Agriculture, Umudike, Nigeria

  • Department of Physics and Geology, Federal University Otuoke, Otuoke, Nigeria

  • Geotechnical Department, Arab Center for Engineering Studies, Doha, Qatar

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