DBPapers
DOI: 10.5593/sgem2017H/15/S06.056

SEDIMENTOLOGICAL FRAMEWORK OF EARLY CRETACEOUS (RUTBAH FORMATION) IN SABAN FIELD – SYRIA

A. Al Salam Al Khder, S.A. Usmanov, A.S. Borisov, N.V. Bokova
Thursday 23 November 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgemviennagreen.org, SGEM2017 Vienna GREEN Conference Proceedings, ISBN 978-619-7408-26-3 / ISSN 1314-2704, 27 - 29 November, 2017, Vol. 17, Issue 15, 447-454 pp; DOI: 10.5593/sgem2017H/15/S06.056

ABSTRACT

The Rutbah formation is one of the most important reservoirs at the Saban field east of Syria, it can hold up to 40 % of the hydrocarbon volume at the area. The Rutbah formation sediments are belong to the early Cretaceous (late Neocomian age). The Rutbah formation sediments at the Saban field are subdivided according to the well logs accompanied with sedimentological data into two parts from down to top which are; the lower Rutbah and the upper Rutbah. The lower Rutbah forms a good quality reservoir with typical average net/gross of 70%, while the upper Rutbah comprises a low net/gross of <20% sand/shale sequence. The upper Rutbah succession is dominated by mudstone (silty claystone to argillaceous siltstone with minor interbedding of sandstone), which deposited in a low energy, shallow marine shelf following a significant transgressive event. The lower Rutbah succession is composed largely of sandstone, bedded on a scale of one or more meters with decimetre-scale interbeds of mudstones (muddy sandstones and silty mudstones). The Rutbah sediments show complex variations in grain size, silt/clay content and proportion of bioturbation, suggesting major shifts in depositional setting or complex lithofacies geometry in a sand-rich depositional setting. Tidal channel, upper and lower shoreface are the main facies identified in Rutbah formation units. The depositional environment of the Rutbah formation is recognized as a semi-confined estuarine system with shallow marine influence. The environment involves different settings such incised valley, confined estuary system, semi-confined estuary system, tidal creek system and open estuary system.

Keywords: Euphrates, Cretaceous, Rutbah, Saban, Syria