| abstract |
The present invention provides methods, lightweight well cement compositions and additives for the well cement compositions. The methods of the invention for sealing pipe in a well bore penetrating a zone or formation which readily fractures at low hydrostatic pressure is basically comprised of the steps of providing a lightweight cement composition comprised of a hydraulic cement, water and an additive comprising an aqueous suspension of microspheres containing a water swellable clay suspending agent, placing the cement composition in the annulus between the pipe and the well bore and allowing the cement composition to set. |