A procedure that permits using a cement column height in the borehole that normally would cause fracture of a subsurface formation. Stage-cementing operations are conducted after the primary cement job has been completed in a normal manner. When the primary cement hardens, ports are opened in a stage-cementing tool which was placed in the casing string as casing was being installed into the borehole. The second-stage cement is pumped through the ports into the borehole above the top of the primary cement.
Source: API BULLETIN E3, Environmental Guidance Document: Well Abandonment and Inactive Well Practices for U.S. Exploration and Production Operations, First Edition, January 1993 (Reaffirmed June 2000). Global Standards