International Journal of Geosciences, 2024, 15, 40-53
https://www.scirp.org/journal/ijg
ISSN Online: 2156-8367
ISSN Print: 2156-8359
DOI: 10.4236/ijg.2024.151004 Jan. 31, 2024 40 International Journal of Geosciences
The Impact of Model Based Offset Scaling
Technique on the Amplitude Variation with
Offset Responses from 3D Seismic Data
Acquired from the Tano Basin, Offshore Ghana
Striggner Bedu-Addo
*
, Sylvester Kojo Danuor, Aboagye Menyeh
Department of Physics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Abstract
Amplitudes have been found to be a function of incident angle and offset.
Hence data required to test for amplitude variation with angle or offset needs
to have its amplitudes for all offsets preserved and not stacked. Amplitude
Variation with Offset (AVO)/Amplitude Variation with Angle (AVA) is ne-
cessary to account for information in the offset/angle parameter (mode con-
verted S-wave and P-wave velocities). Since amplitudes are a function of the
converted S- and P-waves, it is important to investigate the dependence of
amplitudes on the elastic (P- and S-waves) parameters from the seismic data.
By modelling these effects for different reservoir fluids via fluid substitution,
various AVO geobody classes present along the well and in the entire seismic
cube can be observed. AVO analysis was performed on one test well (Well_1)
and 3D pre-stack angle gathers from the Tano Basin. The analysis involves
creating a synthetic model to infer the effect of offset scaling techniques on
amplitude responses in the Tano basin as compared to the effect of unscaled
seismic data. The spectral balance process was performed to match the am-
plitude spectra of all angle stacks to that of the mid (26˚) stack on the test
lines. The process had an effect primarily on the far (34˚ - 40˚) stacks. The
frequency content of these stacks slightly increased to match that of the near
and mid stacks. In offset scaling process, the root mean square (RMS) ampli-
tude comparison between the synthetic and seismic suggests that the am-
plitude of the far traces should be reduced relative to the nears by up to
16%. However, the exact scaler values depend on the time window consid-
ered. This suggests that the amplitude scaling with offset delivered from
seismic processing is only approximately correct and needs to be checked
How to cite this paper: Bedu-Addo, S.,
Danuor, S.K. and Menyeh, A. (2024) The
Impact of Model Based Offset Scaling Tech-
nique on the Amplitude Variation with Offset
Responses from 3D Seismic Data Acquired
from the Tano Basin, Offshore Ghana. Inter-
national Journal of Geosciences, 15, 40-53.
https://doi.org/10.4236/ijg.2024.151004
Received: December 28, 2023
Accepted: January 28, 2024
Published: January 31, 2024
Copyright © 2024 by author(s) and
Scientific Research Publishing Inc.
This work is licensed under the Creative
Commons Attribution International
License (CC BY 4.0).
http://creativecommons.org/licenses/by/4.0/
Open Access