Foamed cement operations require not only a better understanding of foam quality during placement, but also good control of nitrogen injection. This will ensure well security during placement and provide well integrity after placement.

Real-time foam cementing process control system is capable of handling abrupt changes in the cement slurry pump rate which allows for the delivery of quality foamed cement with the designed proportions of gaseous nitrogen and surfactants. The system can also perform process controlled 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 foamed cement placement simulator provides better understanding on the evolution of foam quality across the wellbore during the placement. The 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 placement and after cement is 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 in order to meet the job objectives.

The combination of these two technologies would effectively reduce the operational complexities on foamed cement jobs, which would substantially increase success rate and enhance well integrity assurance.

Several case studies of foamed cement jobs performed in Gulf of Mexico are presented where the use of both real-time process control and dynamic placement simulations resulted in successful execution and proper cement placement.