1887
Volume 39 Number 5
  • ISSN: 0263-5046
  • E-ISSN: 1365-2397

Abstract

Abstract

In 2019, ADNOC decided to record walkabove and walkaway VSP surveys in a deep deviated well, in ultra-shallow waters offshore Abu Dhabi. The field is part of a major gas and condensate development project in UAE. The primary objectives included vertical travel times and velocities, robust well to seismic tie, and higher-resolution VSP images of the Palaeozoic-age targets. Other objectives included acoustic impedance inversion and anisotropy calibration. This was the first time a walkaway was acquired with only 2 m of water depth and in a deep hostile downhole environment. This study showed the importance of pre-survey modelling to achieve the VSP objectives. The data were acquired in continuous mode with GPS time stamping. Good data quality was recorded, despite high temperature, deep targets, multiple casings and a small volume seismic source deployed at 1 m depth. Wideband 5–90 Hz data were retrieved across 6 km of complex overburden, resulting in images with three-fold resolution improvement compared to the surface seismic data. The VSP also provided acoustic impedance sections of the deeper targets and measurements to optimize surface seismic processing. The results validate the viability of 3DVSP surveys with similar shallow-water source and downhole receiver array for reservoir characterization and well placement.

Loading

Article metrics loading...

/content/journals/10.3997/1365-2397.fb2021033
2021-05-01
2021-05-11
Loading full text...

Full text loading...

References

  1. Ali, Y. and A. Nehaid, H.
    [2007]. A Case Study of Porosity Prediction from Seismic Inversion in a Carbonate Oilfield, Abu Dhabi, UAE. 69th EAGE Conference and Exhibition incorporating SPE EURO-PEC.
    [Google Scholar]
  2. Cao, D., Hirabayashi, N., Leaney, S., Borland, W. and Hara, K.
    [2000]. An integrated 3-D tomographic inversion – Application to multi-survey VSP data: 70th Ann. Int. Mtg, SEG Expanded Abstracts, 1779–1782.
    [Google Scholar]
  3. Chapman, C.H. and Pratt, R.G.
    [1992]. Traveltime tomography in anisotropic media – I, J. Int.109, 1–19.
    [Google Scholar]
  4. Miller, D., Oristaglio, M.
    and G.Beylkin [1987]. A new slant on seismic imaging: Migration and integral geometry: Geophysics, 52, 943–964.
    [Google Scholar]
  5. Muller, K., Soroka, W., Paulsson, B., Marmash, S., Al Baloushi, M. and Al Jeelani, O.
    [2010]. 3D VSP technology now a standard high-resolution reservoir-imaging technique: Part 2, interpretation and value.The Leading Edge, 29(6), 698–704.
    [Google Scholar]
  6. Takougang, E. and Bouzidi, Y.
    [2018]. Imaging high-resolution velocity and attenuation structures from walkaway vertical seismic profile data in a carbonate reservoir using visco-acoustic waveform inversion.Geophysics, 83, B323–B337.
    [Google Scholar]
  7. Takougang, E., Ali, M., Bouzidi, Y., Bouchaala, F., Sultan, A. and Mohamed, A.
    [2020]. Characterization of a carbonate reservoir using elastic full-waveform inversion of vertical seismic profile data.Geophysical Prospecting, 68(6), 1944–1957.
    [Google Scholar]
  8. Yin, S.-Z., Bai, G-P., Gao, L. and Xu, C-Y.
    [2018]. A facies and palaeogeography-based approach for analysis of petroleum systems in United Arab Emirates, Journal of Palaeogeography, 7, 168–178.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.3997/1365-2397.fb2021033
Loading
/content/journals/10.3997/1365-2397.fb2021033
Loading

Data & Media loading...

  • Article Type: Research Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error