Print this pageAAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
Exploring the Ordovician Ghudun Play in North Oman: Challenges and Way Forward
(1) Exploration, Petroleum Development Oman, Muscat, Oman.
As conventional hydrocarbon plays have become highly mature after more than 50 years of exploration, Petroleum Development Oman (PDO) is increasingly focusing towards un-conventional plays. The Ghudun stratigraphic play is one example where Ordovician Ghudun sandstone reservoirs are sealed, vertically and laterally, by shales of the overlying Ordovician-Silurian Safiq Group. The Safiq Group consists of three member formations namely Saih Nihayda, Hasirah and Sahmah, listed from old to young.
Evaluation of the play was initiated with studies reviewing serendipitous Ghudun discoveries and subsurface data gathered over several decades. From these studies emerged the Ghudun stratigraphic play with several sub-play segments. The risks and uncertainties associated with the play are spatially variable, reflecting the various play segments, spans multiple geological domains and has variable oil and gas charge potential. The main challenge associated with this play is the difficulty in mapping Top Ghudun on seismic data (due to low impedance contrasts). This challenge forced PDO to seek alternative technologies such as gravity modeling and advanced seismic techniques e.g. neural net approaches to effectively unlock the play potential.
The play segment which is described is the Safiq Canyon Play Segment where canyons have eroded most of Saih Nihayda and some part of Upper Ghudun and are sealed by the Safiq shales. A cluster of prospects has been matured and a well was drilled in 2008. The drilling results have been disappointing but they highlighted risks that were not originally captured and technologies have been recognized which can mitigate these risks. The drilling results have resulted in updating our understanding of the Ghudun play.
In this paper we propose to describe the play elements and the techniques that have been used to date to unravel the challenging Ghudun play.