Methods of preventing well cement stress failure

摘要

Improved methods of cementing in a well are provided whereby stress failures in the resulting set cement are prevented or reduced. The methods basically comprise the steps of placing a foamed cement composition in a zone in the well to be cemented which when set has sufficient elastic properties to resist stress failure comprised of hydraulic cement, water, a gas present in an amount in the range of from about 5% to about 75% by volume of the cement composition and a foaming agent, and then allowing the cement composition to set across the zone.