Decoding of seismic data for complex stratigraphic traps revealing by seismic attributes analogy in Yidma/Alamein concession area Western Desert, Egypt

Sandstone channels are one of the best stratigraphic traps for hydrocarbon accumulation, and their depositional and composition make them difficult to detect on ordinary seismic data, especially in structurally affected onshore areas like the Western Desert of Egypt. The Western Desert of Egypt has many hydrocarbon-bearing reservoirs of various compositions like carbonates and sandstones with high production rates, and thus the Western Desert of Egypt is recognized as a hot spot for oil and gas exploration. One of the important reservoirs in the Lower Cretaceous the Aptian sand produced around 285 MBBLS cumulative oil of 22 degrees API and still produces 102 BOPD. This reservoir has a channel-type depositional environment, and the dimensions of this channel could be resolved by good quality 3D seismic data in the moderately deep basins as the basins become deeper, the detection of the channel becomes increasingly challenging. This study aims to delineate the geometry of this reservoir and reveal the exposure from the Aptian sand channel in the Alamein area using the seismic attributes analogy on the re-processed 3D seismic data to determine the best drilling location for increasing the production from this reservoir. In this context, the relative acoustic impedance (RAI), iso-frequency components, and sweetness stratigraphic attribute analyses were conducted on the optimized seismic data and attested as important as they resolved the stratigraphic geological mystery in the structurally affected study area. These attribute analyses revealed the exposure from the distinctive meander channel of the Aptian sand for the first time in the study area nearby the producing Alamein field, where this channel was hard to be distinguished by the ordinary seismic interpretation methods and there is no drilled well penetrated the detected channel's body. Upon the results, the conclusion and recommendation summaries to intensify the efforts to test the productivity of the detected channel to increase the production from this motivating reservoir by drilling a new well targeting the best structural locations of the channel body.

Automated summary

This study used seismic attribute analogy on re-processed 3D seismic data to delineate the geometry and exposure of the Aptian sand channel in the Alamein area of the Western Desert of Egypt. The results provide guidance for determining the best drilling location to increase production from this reservoir.