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Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh

Received: 23 June 2014     Accepted: 10 July 2014     Published: 20 July 2014
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Abstract

The Fenchuganj Gas Field is one of the water-drive gas fields in the Surma Basin, Bangladesh. Due to gas production water saturation is increasing day by day. However, fluid properties of the reservoir at the present state in the gas depleted condition should be addressed with proper prediction. In this paper, we represent some modeling results which evidences that the pore fluids have a significant effect on the acoustic impedance and the Poisson’s ratio of the reservoir rock which is directly correlated with seismic amplitudes at constant pressure with Batzle-Wang model and Gassman-Boit models. Moreover, these models with varying pressure and water saturation conditions show the reasonable predicted fluid modulus against pressure. The reservoir modeling from irreducible water saturation conditions (90% gas saturation) to residual gas conditions (10% gas saturation) provides a pathway to calculate values at reservoir conditions from logging conditions. Fluid bulk density increases when water saturation increases with constant pressure and stay around constant when water saturation increases with pressure fall. But overall it increases through the production path that we assumed. Amplitude versus Offset (AVO) analysis also consistent with other studies models which show that seismic reflection of p-wave changes due to change of pressure and water saturation of the reservoir rock layers. The AVO response decreases with increases of water saturation of the gas zones. The evaluation of fluid properties enables seismic data to be used more powerfully. This study is also showing that both gas zones of the Fenchuganj are under gas sand category 3. We suggest that the modeling of fluid property in determining the usefulness of time lapse seismic, predicting AVO and amplitude response, and making production and reservoir engineering decisions and forecasting in the study field.

Published in International Journal of Oil, Gas and Coal Engineering (Volume 2, Issue 3)
DOI 10.11648/j.ogce.20140203.12
Page(s) 36-54
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), 2014. Published by Science Publishing Group

Keywords

Fluid, Reservoir, Gas Sand, Saturation, and AVO

References
[1] Zoeppritz, K., 1919, Erdbebenwellen VIIIB, On the reflection and propagation of seismic waves, Gottinger Nachrichten, I, p. 66-84.
[2] Gassmann, F., 1951, Elastic waves through a packing of spheres: Geophysics, 16, 673-685.
[3] Biot, M. A., 1956, Theory of propagation of elastic waves in a fluid-saturated porous solid: Journal of Acoustical Society of America, 28, 168-191.
[4] Kuster, G.T., and Toksöz, M.N., 1974, Velocity and attenuation of seismic waves in two-phase media: Part I. theoretical formulations: Geophysics, 39, 587-606.
[5] O'Connell R., Budiansky B. 1974, Seismic velocities in dry and saturated crack solids. Journal of geophysical Research, 79, 5412-5426.
[6] Rutherford, S.R. and Williams, R.H., 1989, Amplitude-versus-offset variations in gas sands: Geophysics, 54, 680-688.
[7] Mavko, G., and Jizba, D. 1991, Estimating grain-scale fluid effects on velocity dispersion in rocks, Geophysics, 56(12), 1940–1949, doi:10.1190/1.1443005.
[8] Batzle, M. and Wang, Z., 1992, Seismic properties of pore fluids: Geophysics, Vol. 57(11), 1396-1408.
[9] Sheriff, R.E., 1991, Encyclopedic Dictionary of Exploration Geophysics, 3rd Edition: SEG Geophysical References Series 1, Tulsa, USA, p. 384.
[10] Castagna, J.P. and Swan, H.W., 1997, Principles of AVO crossplotting: The Leading Edge, 16, 337-342.
[11] Bulloch, T.E., 1999, The Investigation Of Fluid Properties And Seismic Attributes For Reservoir Characterization, M.Sc thesis for Geological Engineering, Michigan TechnologicaI University, USA.
[12] Annual Report, 2010, Bangladesh Petroleum Exploration and Production Company Limited (BAPEX), Bangladesh
[13] Mannan, M. A., 2002, Stratigraphic evolution and geochemistry of the Neogene Surma Group, Surma Basin, Sylhet, Bangladesh, PhD Dissertation, Department of Geology, University of Oulu.
[14] Farhaduzzaman, M., Wan Hasiah A., Islam, M. A., and Pearson, M. J., 2012, Source rock potential of the organic-rich shales in the Tertiary Bhuban and BokaBil Formations, Bengal Basin, Bangladesh. Journal of Petroleum Geology, 35 (4), 357-376.
[15] Sheriff, R.E., and Geldart, L.P., 1995, Exploration Seismology, 2nd Edition: Cambridge University Press, New York, USA, p. 592.
[16] Murphy, W.F., Schwartz, L.M., and Hornby, B., 1991, Interpretation physics of Vp and Vs in sedimentary rocks: Transactions SPWLA 32nd Annual Logging Symp., p. 1-24.
[17] Schlumberger Oilfield Glossary. (URL: http://www.glossary.oilfield.slb.com/en/Terms.aspx?LookIn=term%20name&filter=amplitude%20variation%20with%20offset)
[18] Mavko, G., Mukerji, T., Dvorkin, J., 1998, The Rock Physics Handbook: Tools for Seismic Analysis in Porous Media: Cambridge University Press, Cambridge, New York, USA, 329 pp.
[19] Castagna, J. P., and Backus, M. M., 1993, Offset-Dependent Reflectivity -Theory and Practice of AVO Analysis: SEG Investigations in Geophysics Series, 8, Tulsa, USA, 348.
[20] Hales, A.L., and Roberts, J.L., 1974, The Zoeppritz amplitude equations: more errors: Bulletin of Seismological Society of America, Vol. 64, p. 285.
[21] Aki, K., and Richards, P.G., 1980, Quantitative seismology: Theory and methods: W. H. Freeman and Co.
[22] Shuey, R.T., 1985, A simplification of the Zoeppritz equations: Geophysics, 50, 609-614
[23] Hilterman, F., 1989, Is AVO the seismic signature of rock properties? 59th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 559.
[24] Knigh R, Nolen-Hoeksema R. A., 1990, laboratory study of the dependence of elastic wave velocities on pore scale fluid distribution. Geophysical Research Letters, 17 (10), 1529-1532.
[25] Liu Zhupin, WU Xiaowei, Chu Zehan 1994, Laboratory study of acoustic parameters of rock. Chinese Journal of Geophysics (Acta Geophysica Sinica), 37 (5): 659-666.
[26] Gregory A R. Fluid saturation on dynamic elastic properties of sedimentary rocks. Geophysics, 1976, 41 (5), 895-921.
[27] Lee, M.W., 2003, Elastic Properties of Overpressured and Unconsolidated Sediments, U.S. Geological Survey Bulletin 2214, Version 1.0, 1-10.
[28] Gardner, G. H. F. and Harris, M.H., 1968, Velocity and attenuation of elastic waves in sands: Society of Professional Well Log Analysts, Transactions, 9th Annual Log Symposium, p. M1–M19.
[29] Pickett, G.R., 1963, Acoustic character logs and their applications in formation evaluation: Journal of Petroleum Technology, 15, 650–667.
[30] Deb, P. K., 2011, An application of seismic and well log techniques to the structural and stratigraphic development of Fenchuganj Gas Field, B.Sc thesis, Department of Petroleum and Mining Engineering, SUST, Bangladesh.
Cite This Article
  • APA Style

    S. M. Ariful Islam, Md Shofiqul Islam, Mohammad Moinul Hossain. (2014). Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh. International Journal of Oil, Gas and Coal Engineering, 2(3), 36-54. https://doi.org/10.11648/j.ogce.20140203.12

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    ACS Style

    S. M. Ariful Islam; Md Shofiqul Islam; Mohammad Moinul Hossain. Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh. Int. J. Oil Gas Coal Eng. 2014, 2(3), 36-54. doi: 10.11648/j.ogce.20140203.12

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    AMA Style

    S. M. Ariful Islam, Md Shofiqul Islam, Mohammad Moinul Hossain. Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh. Int J Oil Gas Coal Eng. 2014;2(3):36-54. doi: 10.11648/j.ogce.20140203.12

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  • @article{10.11648/j.ogce.20140203.12,
      author = {S. M. Ariful Islam and Md Shofiqul Islam and Mohammad Moinul Hossain},
      title = {Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh},
      journal = {International Journal of Oil, Gas and Coal Engineering},
      volume = {2},
      number = {3},
      pages = {36-54},
      doi = {10.11648/j.ogce.20140203.12},
      url = {https://doi.org/10.11648/j.ogce.20140203.12},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ogce.20140203.12},
      abstract = {The Fenchuganj Gas Field is one of the water-drive gas fields in the Surma Basin, Bangladesh. Due to gas production water saturation is increasing day by day. However, fluid properties of the reservoir at the present state in the gas depleted condition should be addressed with proper prediction. In this paper, we represent some modeling results which evidences that the pore fluids have a significant effect on the acoustic impedance and the Poisson’s ratio of the reservoir rock which is directly correlated with seismic amplitudes at constant pressure with Batzle-Wang model and Gassman-Boit models. Moreover, these models with varying pressure and water saturation conditions show the reasonable predicted fluid modulus against pressure. The reservoir modeling from irreducible water saturation conditions (90% gas saturation) to residual gas conditions (10% gas saturation) provides a pathway to calculate values at reservoir conditions from logging conditions. Fluid bulk density increases when water saturation increases with constant pressure and stay around constant when water saturation increases with pressure fall. But overall it increases through the production path that we assumed. Amplitude versus Offset (AVO) analysis also consistent with other studies models which show that seismic reflection of p-wave changes due to change of pressure and water saturation of the reservoir rock layers. The AVO response decreases with increases of water saturation of the gas zones. The evaluation of fluid properties enables seismic data to be used more powerfully. This study is also showing that both gas zones of the Fenchuganj are under gas sand category 3. We suggest that the modeling of fluid property in determining the usefulness of time lapse seismic, predicting AVO and amplitude response, and making production and reservoir engineering decisions and forecasting in the study field.},
     year = {2014}
    }
    

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  • TY  - JOUR
    T1  - Investigation of Fluid Properties and their Effect on Seismic Response: A Case Study of Fenchuganj Gas Field, Surma Basin, Bangladesh
    AU  - S. M. Ariful Islam
    AU  - Md Shofiqul Islam
    AU  - Mohammad Moinul Hossain
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    DO  - 10.11648/j.ogce.20140203.12
    T2  - International Journal of Oil, Gas and Coal Engineering
    JF  - International Journal of Oil, Gas and Coal Engineering
    JO  - International Journal of Oil, Gas and Coal Engineering
    SP  - 36
    EP  - 54
    PB  - Science Publishing Group
    SN  - 2376-7677
    UR  - https://doi.org/10.11648/j.ogce.20140203.12
    AB  - The Fenchuganj Gas Field is one of the water-drive gas fields in the Surma Basin, Bangladesh. Due to gas production water saturation is increasing day by day. However, fluid properties of the reservoir at the present state in the gas depleted condition should be addressed with proper prediction. In this paper, we represent some modeling results which evidences that the pore fluids have a significant effect on the acoustic impedance and the Poisson’s ratio of the reservoir rock which is directly correlated with seismic amplitudes at constant pressure with Batzle-Wang model and Gassman-Boit models. Moreover, these models with varying pressure and water saturation conditions show the reasonable predicted fluid modulus against pressure. The reservoir modeling from irreducible water saturation conditions (90% gas saturation) to residual gas conditions (10% gas saturation) provides a pathway to calculate values at reservoir conditions from logging conditions. Fluid bulk density increases when water saturation increases with constant pressure and stay around constant when water saturation increases with pressure fall. But overall it increases through the production path that we assumed. Amplitude versus Offset (AVO) analysis also consistent with other studies models which show that seismic reflection of p-wave changes due to change of pressure and water saturation of the reservoir rock layers. The AVO response decreases with increases of water saturation of the gas zones. The evaluation of fluid properties enables seismic data to be used more powerfully. This study is also showing that both gas zones of the Fenchuganj are under gas sand category 3. We suggest that the modeling of fluid property in determining the usefulness of time lapse seismic, predicting AVO and amplitude response, and making production and reservoir engineering decisions and forecasting in the study field.
    VL  - 2
    IS  - 3
    ER  - 

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Author Information
  • Department of Petroleum and Mining Engineering, Shahjalal University of Science and Technology, Sylhet 3114 Bangladesh

  • Department of Petroleum and Mining Engineering, Shahjalal University of Science and Technology, Sylhet 3114 Bangladesh

  • Geophysical division, Bangladesh Petroleum Exploration and Production Company (BAPEX), Dhaka, Bangladesh

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