Seismic Imaging and Reservoir Architecture of Sub-Marine Channel Systems Offshore West Nile Delta of Egypt

Abstract

Offshore Nile Delta gas reservoirs are dominated by slope-channel systems of Plio-Pleistocene age. High-quality, three-dimensional seismic imaging has significantly helped in defining the geomorphology and architectures of these channels. Integrating seismic, logs and core data from four wells resulted in understanding of different stages of channel development and reservoir quality. The studied reservoirs that are largely controlled by episodes of transgressive-regressive events resulted in deposition of fine grained sediment and shale. Sienna channel complex consists of unconfined channel system with clearly defined development stages. The stages include amalgamated or stacked channels followed by channel abandonment phases and local flooding events. The depositional pattern continued through the Late Pliocene-Pleistocene. SimSat-P1 and Sim-Sat-P2 reservoirs are characterized by isolated sand bodies, most probably relics of fan depositional setting. The depositional scenario that is largely controlled by successive transgression and flooding events resulted in deposition of interbedded, sheet-like, fine grained sediment and shale.

Increased Land Subsidence and Sea-Level Rise Are Submerging Egypt’s Nile Delta Coastal Margin

“…It is defined by step faults and gravityinduced displacements associated with down-to-north rotated fault blocks that extend from deep structural offsets to the surface. Geophysical surveys show that such features mapped in subsurface on land in the northern delta block continue at depth offshore (Sharaf et al, 2014). Ground motion measurements indicate that these can affect both surface deposits of the northern delta and seafloor strata offshore (Mohamed et al, 2015).…”

Integrated seismic and well gamma-ray analysis for delineation Sienna channel depositional architecture, offshore West Nile Delta, Egypt

“…This became clear after correlating seismic signature with well log data; starting from attribute maps passing through a rock physics model "lithology and fluid discrimination" to gamma-ray logs which enhance lithology interpretation and channel depositional cycles finning upward cycles'. Sharaf et al (2014) studied the sienna area but little bit using seismic techniques to enhance the depositional history of the channel as seismic methods helped us a lot to clear understand reservoir architecture but Sharaf et al (2014) studied more in lithofacies analysis which is a good point after constructing more accurate model analysis.…”

“…Exploration across the Nile Delta started by onshore Messinian incised valleys then offshore discoveries which made on the extension of this play and subsequently on new plays such as the Pliocene shallow marine reservoirs of the Rosetta field (Kijtzscii 1984) (EGPC [Egyptian General Petroleum Corporation] 1994) (Eid et al 2019). Sharaf et al, 2014. Studied the Sienna area in the framework of lithofacies analysis and integrate with seismic data as Seismic time slices indicate that the Sienna channel complex consists of an unconfined channel system with clearly defined evolution stages.…”

Seismic geomechanics of mud volcanoes

“…Pliocene-Quaternary sedimentary cover within the region has received an abundant supply of clay-dominated terrigenous deposits (Macgregor 2012 Dolson et al 2001;Sharaf 2003;Ismail et al 2010 ;Sharaf et al 2014;Tassy et al 2015;Leila et al 2016;Makled et al 2017b).…”

“…al. 2001;Sharaf 2003;Ismail et al 2010;Sharaf et al 2014;Tassy et al 2015;Leila et al 2016;Makled et al 2017b) Today the two main fluvial pathways across the onshore Nile delta are the Rosetta branch in the west and the Damietta branch in the east. Offshore there is a wide continental platform passing northwards into the Nile Deep Sea Fan which covers the continental slope and parts of the abyssal plain to a depth of ~3500 m (Fig.…”