Utilizing Seismic-Derived Rock Properties in Well Planning, Drilling and Geosteering Khafji Stringer Sands, Zuluf field, Saudi Arabia

Sean A. Rahati*, Hussain Al-Otaibi, Yousef Al-Shobaili, and Randal Miller
Saudi Aramco
*[email protected]

The northern offshore Khafji Stringer Sands contain substantial oil reserves, yet imaging these sands has up to now been elusive. The target sands and shales do not have sufficient acoustic impedance contrast to appear in normal incident seismic data and the distribution is too erratic to be predicted with subsurface stratigraphic techniques. Simultaneous Offset Inversion was used to separate sands from shales in the angle-stack domain based on elastic rock properties. Used for the first time at Saudi Aramco, the results have made it possible to target thin sands using geosteered horizontal wells to maximize reservoir contact, production and ultimate recovery while reducing horizontal well tortuosity and drilling time. In this case study we will review the simultaneous offset inversion methodology and implementation as successfully applied to three horizontal wells.

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