Structural growth control of the Khuff exploration play in eastern Saudi Arabia

Faqira, Mohammad I. (Saudi Aramco - [email protected]), Murdy M. Al-Zahrani (Saudi Aramco), James L. Rico (Saudi Aramco), Khalid M. Shokair (Saudi Aramco), Michael A. Zinger (Saudi Aramco). Nezar A. Al-Talhah (Saudi Aramco) and William B. Stone (Saudi Aramco

Well and seismic data studies document that the Khuff gas play is primarily controlled by several structural growth periods from Carboniferous to Neogene time. The play is sourced by the Silurian Qusaiba hot shale, whose distribution is controlled by ÔHercynianÕ structural growth and is seismically mappable in eastern Saudi Arabia. Khuff A, B, and C reservoir development was controlled by the Permo-Triassic structural growth over Ghawar field and other trends in the area. The syn-depositional growth of these trends during the Khuff time contributed to reservoir development for two reasons: (1) relatively high paleotopography may have developed a high-energy environment, which set the reservoir quality framework of the Khuff reservoir; and (2) higher magnitude growth of these relative highs may have controlled the early dolomitization process and the porosity and permeability enhancement. The structural growth maps of the Khuff Formation suggest that most four-way dip closures in eastern Saudi Arabia developed in the Late Cretaceous and Early Neogene times. During these times the base Qusaiba source rock was generating wet and dry gases. Fluid inclusion results from Ghawar field Khuff reservoirs confirm the timing of the trap development by showing condensate fluids dated between 96 to 106 Ma. The high magnitude of the Late Cretaceous and Neogene growth reactivated some of the ÔHercynianÕ faults that provide an excellent conduit between the Qusaiba source and the Khuff reservoirs in the area.

Faqira, Mohammad I., Al-Zahrani, Murdy M., Rico, James L., Shokair,, Khalid M. , Zinger, Michael A., Al-Talhah, Nezar A. , Stone, William B., 2004, Structural growth control of the Khuff exploration play in eastern Saudi Arabia: Geo 2004, Bahrain, Gulf Petrolink.