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Sea state description of Asabo offshore in Nigeria

  • Jasper, Agbakwuru A. (Center for Maritime and Offshore Studies, Federal University of Petr. Resources Effurun) ;
  • Bernard, Akaawase T. (Center for Maritime and Offshore Studies, Federal University of Petr. Resources Effurun) ;
  • Gudmestad, Ove T. (University of Stavanger)
  • 투고 : 2018.09.09
  • 심사 : 2019.11.15
  • 발행 : 2020.03.25

초록

A study of the wave conditions for the Asabo offshore location at the Qua Iboe oil field in Eastern Nigeria has been carried out. Statistical analysis was applied to three (3) years of data comprising spectral periods, Tp and significant wave heights, Hs. The data was divided into two (2); data from October to April represents one set of data and data from May to September represents another set of data. The results were compared with similar studies at other locations offshore of West Africa. It was found that there is an absence of direct swellwaves from the Southern Ocean reaching the location under study (the Asabo site). This work suggests that the wave system is largely emanating from the North Atlantic storms. The presence of numerous islands near the Asabo location shields the site from effects of storms from south west and therefore swells from the Southern Ocean. It is noted that the local wind has little or no contribution. An Hs maximum of 2 m is noted at the Asabo offshore location. It is found that the Weibull distribution best describes the wave distribution at Asabo. Thus, the Weibull distribution is suggested to be adequate for long term prediction of extreme waves needed for offshore design and operations at this location.

키워드

과제정보

The Authors are grateful to SHELL Nigeria for the provision of the data for this work and to The Federal University of Petroleum Resources, Effurun, Nigeria, and the University of Stavanger, Norway, for collaboration on this study.

참고문헌

  1. Agbakwuru, J.A. and Akaawase, B.T. (2018), "Evaluation of wind energy potentials in Nigerian Onshore and Offshore locations", FUPRE J. Scientific Ind. Res., 4-12.
  2. Akinsanya, A.O., Gudmestad, O.T. and Agbakwuru, J.J. (2017), "Swell description for Bonga Offshore Nigerialocation", Ocean Syst. Eng., 20(4), 7-10.
  3. Alves, J.H. (2006), "Numerical modeling of ocean swell contributions to the global wind wave climate". Ocean Modelling, Vol. 11 (1-2), pp. 98-122. https://doi.org/10.1016/j.ocemod.2004.11.007
  4. Ardhuin, F., Bertrand, C. and Fabrice, C. (2009), "Observation of swell dssipation across oceans", Geophys. Res. Lett., 39, 12-18.
  5. Barber, N.F. andUrsell, F. (1948), "The generation and propagation of ocean waves and swell. Wave periods and velocities", Philos. T. Roy. Soc. London, 240, 527-560. https://doi.org/10.1098/rsta.1948.0005
  6. Bhowmick, S., Kumar, R., Chaudhuri, S. and Sarkar, A. (2011), "Swell propagation over Indian Ocean Region". Int. J. Ocean Clim. Sys., 2(5), 87-99. https://doi.org/10.1260/1759-3131.2.2.87
  7. Chen, G., Chapron, B., Ezraty, R. and Vandemark, D. (2002), "A global view of swell and wind sea climate in the ocean by satellite altimeter and scatterometer", J. Atmos. Ocean. Technol., 19(11), 1849-1859. https://doi.org/10.1175/1520-0426(2002)019<1849:AGVOSA>2.0.CO;2
  8. Chen, Y.H., Francis, J.A. and Miller, J.R. (2002), "Surface temperature of the arctic: Comparison of TOVS satellite retrievals with surface observations", J.Climate, 15(2),10.1175/1520-0442, 3698-3708.
  9. DNV-RP-H103, (2011), "Modelling and Analysis of Marine Operations, Recommended Practice", LastModifiedApril.https://rules.dnvgl.com/docs/pdf/DNV/codes/docs/2012-12/RP-H103.pdf, pp. 54.
  10. Ewans, K., Forristall, G.Z., Olagnon, M., Prevosto, M. and Van Iseghem, S.(2004), "WASP-West Africa Swell Project - Final Report", 90+192 pp., http://archimer.ifremer.fr/doc/00114/22537/.
  11. Forristall, G.Z., Ewans, K., Olagnon, M. and Prevosto, M.(2013), "The West Africa Swell Project (Wasp) ", Proceedings of the 32nd Int. Conf. on Offshore and Arctic Eng, OMAE 2013-11264, pp. 165-180.
  12. Ginos, B.F. (2009), "Parameter Estimation for the Lognormal Distribution", Master of Science Thesis, Department of Statistics, Brigham Young University, December, 54-88.
  13. Gerling, T.W. (1992), "Partitioning sequences and arrays of directional wave spectra into component wave systems", J. Atmos. Oceanic Technol., 9, 444-458. https://doi.org/10.1175/1520-0426(1992)009<0444:PSAAOD>2.0.CO;2
  14. Hanson, J.L. and Phillips, O.M. (2001), "Automated analysis of ocean surface directional wave spectra", Atmos., Ocean, Technol., 277-293.
  15. Haver, S. (2013), "Prediction of Characteristic Response for Design Purposes", Preliminary Revision 5, Statoil, Stavanger, Norway, pp. 54.
  16. Haver, S. (2016), "Stochastic Description of Ocean Waves & Response Analysis and Prediction of Extremes", Lecture Note, Rev. 1, UIS/NTNU, Norway.
  17. Haver, S. and Nyhus, K.A. (1986), "A wave climate description for long term response calculations". Proceedings of the OMAE, Tokyo.
  18. Kelvin, E., George, Z.F., Michel O. and Sylvie, V.I. (2004), "West African swell project WASP)", Nigeria, 17-34.
  19. Ododo, J.C., Agbakwuru, J.A. andOgbu, F.A. (1996), "Correlation of solar radiation with cloud cover and relative sunshine duration", Energy Conversion and Management, 37(10), October 1996, 1555-1559. https://www.sciencedirect.com/science/article/pii/0196890496868373. https://doi.org/10.1016/0196-8904(96)86837-3
  20. Olagnon, M., Ewans, K., Forristall,G.Z. and Prevosto, M. (2013), "West Africa Swell SpectralShapes", Int. Conf. on Offshore Mech. and Arctic Eng., Proceedings of the OMAE 2013, paper number11228.
  21. Prevosto, M., Ewans, K., Forristall,G.Z. and Olagnon, M.(2013), "Swell Genesis, Modelling and Measurements in West Africa", Int. Conf. on Offshore Mech. and Arctic Eng., Proceedngs of the OMAE 2013-11201.
  22. Sabique, L., Annapurnaiah, K., Nair Balakrishnan, T.M. and Srinivas, K. (2011), "Contribution of Southern Indian Ocean Swells on the Wave Heights in the Northern Indian Ocean. A modeling study", Ocean Eng., 43, 113-120. https://doi.org/10.1016/j.oceaneng.2011.12.024
  23. Samiksha, S.V., Vethamony, P., Aboobacker,V. and Rashmi, R.(2012), "Propagation of Atlantic Ocean Swells in the North Indian Ocean: A Case Study". Natural Hazards and Earth System Sciences, 12(5), 3605-3615. https://doi.org/10.5194/nhess-12-3605-2012