Targeting infill wells in the densely fractured Lekhwair Field, Oman

Abstract

The oil bearing reservoirs of the Lekhwair A-North field in Oman consist of layered low permeability chalky limestones of the Lower Shu'aiba and the Kharaib formations. These have been waterflooded since 1992 by a 200 well development project. However, the field is more faulted and fractured than was anticipated prior to full-scale development and prolific early water breakthrough occurred in many producers (~20%), due largely to direct alignment of injectors and producers along the principal orientation of faults and fractures in the field. As a consequence, the waterflood is currently being converted from a vertical inverted 9-spot well pattern to a line drive orientated parallel to the dominant orientation of faults and fractures in the field. This will result in significantly improved reservoir sweep and oil recovery. Although initially disappointing, production from the field is now well on the way to meeting original expectations.