Method of cementing wells with foam-containing cement

摘要

To cement the annulus around a casing string in a well penetrating an underground formation, a column of cement slurry which is or includes a foam cement slurry is placed in the annulus and allowed to set. The amount of gas contained in the slurry and the set cement is such that the density in the cement slurry column and the cement in the annulus increases with increasing depth.