Foam cementing has been widely used for offshore applications where the formation has low fracturerngradients, and shallow water flow may occur. One challenge of foam cementing is to ensure that thernfoamed slurry is stable at the desired foam qualities with low permeability. Therefore, stabilizers arerncommonly applied along with the foaming agent. This paper describes the comparison testing and severalrnoffshore applications of a new liquid foam stabilizer that improves logistics and flexibility on the rig, andrnprevents excessive viscosity and foaming during mixing.rnThe new liquid foam stabilizer was tested in the laboratory to compare its performance with that of arndry stabilizer used previously in the field. The stabilizer was then used in several offshore wells to assessrnits performance in real-world operations. In particular, one problem with dry foam stabilizers is that theyrncan promote excessive foaming during mixing, which leads to pump cavitation if not controlled with arndefoaming agent. The field operations were arranged to test a new operational procedure for use with thernliquid foam stabilizer to avoid cavitation without a defoamer.rnThe laboratory testing determined that the new solids-free liquid foam stabilizer disperses easily in therncement slurry. The new stabilizer was also found to improve the stability of the foam and the densityrndistribution of the set foam cement compared with no stabilizer. Furthermore, several case histories willrndemonstrate that the combination of the liquid additive and the new operational procedure improved thernslurry mixability without any pump cavitation issues.rnThe new liquid foam stabilizer has more predictable and reliable response than conventional dryrnstabilizers, and the case histories will demonstrate how its use improves cementing flexibility andrnlogistics.
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