Foamed cement operations not only require a solid knowledge of the foam quality during placement, but also good control of nitrogen injection throughout the operation. These two factors ensure optimum well control during placement and provide well integrity after placement completion. A real-time foamed cement process control system is capable of handling dramatic changes in the cement slurry pump rate which allows for delivering quality foamed cement with the designed proportions of gaseous nitrogen and surfactants. The process-controlled system can also perform operations with more than 200 stages of varying nitrogen ratios to provide a near-constant density column of foamed cement in the wellbore. A dynamic compressible fluid placement simulator provides better understanding on the evolution of foam quality across the wellbore during the placement. The simulator computations take into account the influence of circulating pressures and temperatures on nitrogen compressibility. The simulator then evaluates the computed surface and downhole pressures and foam qualities throughout cement placement and after cement in place, and issues warnings whenever those parameters fall outside the design criteria at any time during the operation. Such feedback allows the engineer to adjust the design to meet the job objectives. The combination of these two technologies effectively reduces the operational complexities on foamed cement operations, which will substantially increase the success rate and enhance well integrity. Several case studies of foamed cement operations performed in the Gulf of Mexico are presented in which the use of real-time process control and dynamic placement simulation provided successful job execution and proper cement placement.

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