Unlocking the Remaning Potential of the Thayem
and Nishan Fields from Outcrop and Core Studies,
Al-Ja’Aidi, Omar1, Peter Homewood1, Henk Droste1, Jamal Al Jundi2,
Mohammed Abou Shaker2, Jurgen
Grotsch2 (1) Sultan Qaboos University, Al Khod, Oman (2) Al Furat Oil
The Thayyem and Al Nishan
oil fields are located in north-eastern
Outcrop and core studies indicate that the transgressive and regressive part of the Dhiban Formation are each characterized by different facies associations and two depositional models are required to describe this interval.
The transgressive interval is dominated by moderate energy, good reservoir quality subtidal mollusk sands and littoral deposits closely associated with supra-tidal sabkha. This may suggest the presence of a poorly developed protective barrier and that the inter-tidal and sub-tidal environments may have been isolated by growth of beach bars and spits. In core, the regressive unit displays a more restricted facies association of thick oil stained stromatolites, salina, muds and marls and supra-tidal sabkha. Here the protective barrier is better developed with a low energy inter- to sub-tidal area between the barrier and the supratidal sabkha.
The two depositional models have different implications for the lateral continuity and stacking trends of the reservoir and sealing intervals.