A method and cementing composition is provided for sealing a subterranean
zone penetrated by a well bore, wherein the cementing composition
comprises a mixture of cementitious material, a polymeric cement cohesion
additive, and sufficient water to form a slurry. The polymeric cement
cohesion additive is a high molecular weight hydroxyethylcellulose. The
method comprises placing the cement composition in the subterranean zone
and allowing the cement composition to set into a solid mass therein.