The interpretive stratigraphy of a regional traverse dip section from the Khuff outcrop belt in central Saudi Arabia to Al-Jawb in Eastern Saudi Arabia

Billing, Ian  M. (Saudi Aramco - [email protected]), Denis Vaslet (BRGM), Yves-Michel Le Nindre (BRGM), Abduljaleel Abubshait (Saudi Aramco), Raid Dakhil (Saudi Aramco), Rami Kamal (Saudi Aramco), Aus Tawil (Saudi Aramco), Randy Demaree (Saudi Aramco), Geir Ytreland (Saudi Aramco) and Alastair Gray (Saudi Aramco)

The Permo-Triassic  Khuff Formation in the subsurface of Saudi Arabia acts as a significant gas reservoir, and a detailed sequence stratigraphic scheme has recently been completed for the Khuff in the supergiant Ghawar field in eastern Saudi Arabia.  The challenge then facing carbonate geoscientists was to evaluate this model outside of the Ghawar structure, and produce a regionally-consistent geological framework for this formation. A significant amount of core has been taken in wells outside of Ghawar, and moderately well-exposed outcrops of the Khuff Formation also exist within the Kingdom.  This is the result of a detailed geological study of the Khuff Formation to the south of Ghawar as a step in the creation of a regional Khuff Formation model across the entire Arabian Shelf. The Khuff Formation outcrops in a narrow 600-km-long arcuate N-S belt in central Arabia, to the west of Riyadh.  While providing good information on potential reservoir geometries and an insight into the stacking patterns of these shallow-water to supra-tidal carbonates, linking the outcrops to the subsurface has proved challenging, due to down-dip facies changes and the paucity of diagnostic evaporite markers, which act as significant units for correlation in the subsurface. By compiling a 250 km-long dip-section traverse, utilizing extensive and detailed core descriptions, micropaleontological analysis and wireline log integration, a consistent correlation has been compiled.  This presentation illustrates the results of this traverse from the Qassim outcrops in central Arabia, through shallow-cored water wells, into exploration wells, tying up with the Ghawar field, and terminating at Jawb.  This study represents a major advancement in the regional understanding of the sequence stratigraphy and lateral facies distribution of the Khuff Formation, and will aid future exploration efforts throughout the Arabian Gulf.

Billing, I.M., Vaslet, D., Le Nindre, Y., Abushait, A., Dakhil, R., Kamal, R., Tawil, A., Ytreland, G., and Gray, A, 2004, The interpretive stratigraphy of a regional traverse dip section from the Khuff outcrop belt in central Saudi Arabia to Al-Jawb in Eastern Saudi Arabia: Geo 2004, Bahrain, Gulf Petrolink..