초록 ▼

The present invention provides improved lightweight well cement compositions useful for performing a variety of cementing applications in subterranean formations and particularly for cementing conductor pipe in offshore wells. A preferred cement composition basically comprises a hydraulic cement, an

The present invention provides improved lightweight well cement compositions useful for performing a variety of cementing applications in subterranean formations and particularly for cementing conductor pipe in offshore wells. A preferred cement composition basically comprises a hydraulic cement, an effective amount of an iron salt selected from the group of ferric chloride, ferrous chloride or mixtures thereof to reduce the transition time of the composition, sufficient water to form a pumpable slurry, an effective amount of a foaming additive for producing a foamed slurry, and sufficient gas to foam the slurry.

대표청구항 ▼

1. A method of cementing in a subterranean zone having a temperature of about 65.degree. F. or less using a lightweight well cement composition comprising the steps of:preparing a pumpable lightweight cement slurry having a density of less than about 14 lbs/gal; reducing the transition time of the l

1. A method of cementing in a subterranean zone having a temperature of about 65.degree. F. or less using a lightweight well cement composition comprising the steps of:preparing a pumpable lightweight cement slurry having a density of less than about 14 lbs/gal; reducing the transition time of the lightweight cement slurry by including an effective amount of an iron compound in the composition to reduce the transition time thereof; placing the slurry in the subterranean zone to be cemented wherein said zone has a temperature of about 65.degree. F. or less; and allowing the slurry to set into a hard impermeable mass.