The Barik Sandstone Member, Northern Oman: Stratigraphic Traps and Review of a Tight Gas Play

John F. Aitken*, John A. Millson, Steven G. Fryberger, Alban Rovira, Dieter Skaloud, Hamad Al-Shuaily, Abdullah Al-Habsy, Mohamed Al-Harthy, Celestine Ugwu, Bhupendra N. Singh, and Sre Vaddey
PDO
*[email protected]

The Barik Sandstone Member (Cambrian-Ordovician Haima Supergroup) in northern Oman is the most productive deep and tight gas unit in Oman. The majority of existing dis-coveries are conventional structural closures but much of the remaining potential resides in stratigraphic traps. The Barik Sandstone Member comprises a variety of reservoir facies within an overall continental braid-plain to marginal marine/offshore setting. Through time, the position of the Barik coastline oscillated across northern Oman. Better reservoir devel-opments are associated with sand-rich, fluvial-dominated systems, contemporaneous with regional progradational events, and exhibit abrupt contacts with adjacent marine mud-prone intervals. These progradational units are probably a result of forced regression. Barik strati-graphic-trap configurations rely on the northerly pinchout of these sandstone systems. Ma-jor flooding surfaces, ichnofacies and magnetostratigraphy have assisted in defining a de-tailed intra-reservoir, regional correlation framework for the barren beds of the Barik Sand-stone Member. This framework gives some regional control on intra-Barik reservoir distri-bution and connectivity and facilitates improved understanding of local changes in palaeo-geography, providing a correlation resolution of less than one million years. With limita-tions on the seismic definition of reservoir distribution regional, Barik well penetrations, integrated with outcrop studies, provide the main input into geological models for the Barik Sandstone Member and the basis for play maps. All data have been used in facies model-ling, core-log calibration, depositional environment interpretation, provenance, palaeocur-rent analysis and reservoir quality determination. These parameters have been mapped to generate play maps that assist in defining and testing the stratigraphic pinchout traps in the Barik Sandstone Member and in early appraisal activities in discovered stratigraphic traps.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain