Oilfield applications of colloidal silica gel

This paper reports on a practical reservoir fluid-flow control system based on colloidal silica gel that was developed. Colloidal silica gel is an environmentally benign system that provides easy surface handling, reliable gel-time control at temperatures up to 250{degrees} F, and high in-situ performance. Extensive laboratory testing was completed and is discussed elsewhere. Colloidal silica gel has been used in 11 well work-overs for water-injection-profile modification (four wells), water-production control (three wells), and remedial casing repair (four wells). Only one of the four injection-well treatments was a clear-cut technical success, with failure typically caused by pressure parting the gel plug after the well treatment. Two of the three water-production-control jobs were technical and economic successes. Temporary success was achieved in three of the four casing-repair treatments.