Managing Field Development Uncertainty in the Geologically Complex Stringer Sands in Offshore Saudi Arabia

Abstract

This paper will describe how new technologies, such as geosteering, seismic imaging and new drilling techniques, are being pursued to improve overall net sand reservoir contact and production improvements in horizontal wells. These technologies have been implemented in offshore wells to obtain valuable geological information, improve well placement, and minimize sidetracks by reducing uncertainty. The geologically complex stringer sand reservoir is unconsolidated sandstone with a permeability of 3-5 Darcy. Proper well placement and minimizing costly sidetracks are critical to the success of this offshore field. Improvements in the well placement of horizontal wells within stringer sand reservoirs have improved immensely in the offshore fields of Saudi Arabia. New technologies and techniques involving geosteering, seismic imaging, and well design have been evaluated and field tested, and has improved the net to gross sand ratio from 50% to over 80% with a corresponding increase in production of over 50%, with opportunities for additional improvement.