Delineating the fluvial channel system in the Upper Triassic formation of the Elward area in the Syrian Euphrates Graben using 3-D seismic attributes

Abstract

3-D seismic data were used to evaluate the reservoir in the Mulussa F formation in the Elward area and to discover new drillable locations by delineating the fluvial channel system and the features of its facies. Seismic attributes such as relative acoustic impedance, coherency volume and reflection strength were considered. The attribute maps revealed different types of channels such as braided, meandering and anastomosing channels. They also revealed fluvial features such as point bars, Ox-Bows and crevasse splays, which are considered potential points of hydrocarbon accumulation due to the abundance of sandy bodies. The map of relative acoustic impedance demonstrated that the sandstone beds have high impedance, whereas the shale beds have low impedance. In fact, well data indicated that the shaly beds were surrounded by sandy beds, and their thickness was in the range of 20-25 m within the Mulussa F formation. The coherency attribute showed some of the meandering tributary channels that were not seen on the relative acoustic impedance map. The abundance of fluvial channels in the Euphrates region indicates a large water discharge during the deposition of the Mulussa F formation because of the wet climate prevailing during the Upper Triassic.

The impact of geological uncertainty on primary production from a fluvial reservoir

“…Three-dimensional seismic data are often used to generate pseudo-images of the subsurface. Several studies show that incised valleys, channel belts, large channels (with a thickness above the seismic vertical resolution), and abandoned channels filled with coaly horizons are seismically detectable (Alsouki et al 2014;Zhang et al 2015). In the absence of seismic data, outcrops and modern deposition systems are important sources of information related to sedimentary features.…”