TRANSITION TIME OF CEMENT SLURRIES BETWEEN THE FLUID AND SET STATE.

To predict the occurrence of annular gas flow and design cement slurries capable of helping prevent annular gas flow, it is necessary to define the slurry characteristics at the beginning and end of this transition period as well as the length of time of the transition stage. Test techniques have been developed to study the start of this transition period. Additional tests have been conducted to define the condition of cement required to prevent gas entry. The test techniques developed to define this transition period of a cement slurry are described. Numerous job variables such as pumping time, placement time, slurry composition, circulating temperature and pressure were investigated to evaluate their influence on transition time. A method for using transition time and static gel strength development data to help predict annular gas flow and evaluate annular gas flow control materials is discussed.