scholarly journals Pre-drill pore pressure prediction using seismic velocities for prospect areas at Beni Suef Oil Field, Western Desert, Egypt

2017 ◽  
Vol 7 (4) ◽  
pp. 1011-1021 ◽  
Author(s):  
A. El-Werr ◽  
A. Shebl ◽  
A. El-Rawy ◽  
N. Al-Gundor
Geophysics ◽  
2005 ◽  
Vol 70 (6) ◽  
pp. O39-O50 ◽  
Author(s):  
Øyvind Kvam ◽  
Martin Landrø

In an exploration context, pore-pressure prediction from seismic data relies on the fact that seismic velocities depend on pore pressure. Conventional velocity analysis is a tool that may form the basis for obtaining interval velocities for this purpose. However, velocity analysis is inaccurate, and in this paper we focus on the possibilities and limitations of using velocity analysis for pore-pressure prediction. A time-lapse seismic data set from a segment that has undergone a pore-pressure increase of 5 to 7 MPa between the two surveys is analyzed for velocity changes using detailed velocity analysis. A synthetic time-lapse survey is used to test the sensitivity of the velocity analysis with respect to noise. The analysis shows that the pore-pressure increase cannot be detected by conventional velocity analysis because the uncertainty is much greater than the expected velocity change for a reservoir of the given thickness and burial depth. Finally, by applying amplitude-variation-with-offset (AVO) analysis to the same data, we demonstrate that seismic amplitude analysis may yield more precise information about velocity changes than velocity analysis.


2008 ◽  
Author(s):  
Ehsan Nosrat ◽  
Abdolrahim Javaherian ◽  
Mahmoud Reza Torabi and Homayoun Behzad Asiri

Geophysics ◽  
2002 ◽  
Vol 67 (4) ◽  
pp. 1286-1292 ◽  
Author(s):  
C. M. Sayers ◽  
G. M. Johnson ◽  
G. Denyer

1A predrill estimate of pore pressure can be obtained from seismic velocities using a velocity‐to–pore‐pressure transform, but the seismic velocities need to be derived using methods having sufficient resolution for well planning purposes. For a deepwater Gulf of Mexico example, significant differences are found between the velocity field obtained using reflection tomography and that obtained using a conventional method based on the Dix equation. These lead to significant differences in the predicted pore pressure. Parameters in the velocity‐to–pore‐pressure transform are estimated using seismic interval velocities and pressure data from nearby calibration wells. The uncertainty in the pore pressure prediction is analyzed by examining the spread in the predicted pore pressure obtained using parameter combinations which sample the region of parameter space consistent with the available well data. If calibration wells are not available, the ideas proposed in this paper can be used with measurements made while drilling to predict pore pressure ahead of the bit based on seismic velocities.


First Break ◽  
2006 ◽  
Vol 24 (1095) ◽  
Author(s):  
L.D. Den Boer ◽  
C.M. Sayers ◽  
Z.R. Nagy ◽  
P.J. Hooyman ◽  
M.J. Woodward

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