Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt
Othman, A., Bakr, A., Maher, A. (2017). Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt. EKB Journal Management System, 6(1), 81-89. doi: 10.1016/j.nrjag.2017.04.008
Adel A.A. Othman; Ali Bakr; Ali Maher. "Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt". EKB Journal Management System, 6, 1, 2017, 81-89. doi: 10.1016/j.nrjag.2017.04.008
Othman, A., Bakr, A., Maher, A. (2017). 'Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt', EKB Journal Management System, 6(1), pp. 81-89. doi: 10.1016/j.nrjag.2017.04.008
Othman, A., Bakr, A., Maher, A. Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt. EKB Journal Management System, 2017; 6(1): 81-89. doi: 10.1016/j.nrjag.2017.04.008

Integrated seismic tools to delineate Pliocene gas-charged geobody, offshore west Nile delta, Egypt

NRIAG Journal of Astronomy and Geophysics
Volume 6, Issue 1, June 2017, Pages 81-89    PDF (5.44 M)
DOI: 10.1016/j.nrjag.2017.04.008
Authors
Adel A.A. Othman; Ali Bakr; Ali Maher
Abstract
Nile delta province is rapidly emerging as a major gas province; commercial gas accumulations have been proved in shallow Pliocene channels of El-Wastani Formation. Solar gas discovery is one of the Turbidities Slope channels within the shallow Pliocene level that was proved by Solar-1 well.
The main challenge of seismic reservoir characterization is to discriminate between Gas sand, Water sand and Shale, and extracting the gas-charged geobody from the seismic data. A detailed study for channel connectivity and lithological discrimination was established to delineate the gas charged geobody.
Seismic data, being non-stationary in nature, have varying frequency content in time. Spectral decomposition of a seismic signal aims to characterize the time-dependent frequency response of subsurface rocks and reservoirs for imaging and mapping of bed thickness and geologic discontinuities. Spectral decomposition unravels the seismic signal into its constituent frequencies.
A crossplot between P-wave Impedance (Ip) and S-wave Impedance (Is) derived from well logs (P-wave velocity, S-wave velocity and density) can be used to discriminate between gas-bearing sand, water-bearing sand, and shale. From Ip vs. Is crossplot, clear separation occurs in the P-impedance so post stack inversion is enough to be applied.
Integration between Inversion results and Ip vs. Is crossplot cutoffs help to generate 3D lithofacies cubes, which is used to extract facies geobodies.
Keywords
Spectral decomposition analysis; seismic attributes; RGB color-blending; Spectral analysis vs. seismic attributes; Seismic reservoir characterization; Seismic inversion; Geobody extraction; Gas-charged geobody delineation
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