Morphological Controls of Submarine Canyons on Reservoir Heterogeneity: Seismic Detection of the Matruh Canyon (Cretaceous, Egypt) and Global Deep-Water Analogues

Abstract

Submarine canyons critically control reservoir heterogeneity in deep-water settings, yet their erosional surfaces often evade seismic detection. This study integrates the instantaneous phase, variance coherence, spectral whitening and acoustic impedance inversion of advanced seismic attributes to resolve the morphology of the Cretaceous Matruh Canyon (Egypt's Western Desert) and quantify its impact on the Alam El Bueib IIIG reservoir. Conventional 2D seismic data initially obscured the canyon's basal erosional surface due to velocity push-down artefacts and sparse line spacing. Our workflow successfully delineated a U-shaped, fault-controlled incision system, revealing stark thickness variations (> 440 ft locally) where canyon infill replaced reservoir sands with sealing Matruh Shale. Paradoxically, while this erosion disrupted continuity evidenced by shale-plugged wells (e.g., Emry Deep_04), it concurrently created stratigraphic traps through lateral sand-shale juxtaposition and shale-drape seals. Note that shale gouge ratio analysis confirmed robust lateral seals (> 80%) along bounding faults, notably where shale thickness exceeded 200 ft. We initially struggled to reconcile the abrupt transition from productive sands (Emry Deep_01X) to non-reservoir intervals until spectral whitening resolved thin (< 138 ft) SII sand remnants. Global analogues (Brazil Pre-salt, Niger Delta) highlight Matruh's uniqueness: its syn-rift tectonic setting and > 400-m incision depth create traps distinct from post-rift carbonates or shale diapirs.

Keywords

alam el bueib formation / cretaceous syn-rift basins / seismic attribute analysis / shale gouge ratio (SGR) / stratigraphic trap formation / submarine canyons

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2026 Geological Society of China.