Delineating Plio-Pleistocene channels (gas reservoirs) via seismic attributes in Baltim Gas Field, Nile Delta, Egypt

Abstract

The Baltim gas fields in the offshore Nile Delta contain substantial gas condensate accumulations. This study aims to identify Pleistocene (El-Wastani formation) and Pliocene (Kafr El-Sheikh formation) reservoirs. Data from five wells, including gamma-ray, density, neutron, sonic, and resistivity wireline logs, were integrated with seismic data to refine gas horizon interpretation. A synthetic seismogram was generated to assist in correlating these data. Seismic attributes were applied to enhance seismic data interpretation, revealing key geological features. This study focuses on verifying two potential gas anomalies. The first anomaly involves structural attributes, such as discontinuity and fault likelihood, crucial for detecting fault systems and assessing gas leakage. Fault sealing properties, whether fully sealed, partially sealed, or non-sealed, are important for understanding gas accumulation and migration. The second anomaly concerns stratigraphic attributes, using three types: sweetness, reflection strength, and spectral decomposition. Sweetness and reflection strength are effective for identifying gas, highlighting zones with high reflectivity and hydrocarbon presence. Spectral decomposition is particularly valuable for delineating channel fairways, identifying channelized gas-bearing sands, and clarifying the Pliocene anomaly, which indicates prime drilling and development locations. This study integrates 3D reprocessed seismic data from 2018 and well data, providing a comprehensive seismic interpretation that enhances understanding of gas reservoir characteristics.

Keywords

• seismic attributes
• gas reservoirs
• baltim field
• nile delta channels