Temperature-dependent studies of high-performance foamed cements

Abstract

In this study, through-transmission acoustic time-of-flight experiments were used to study the variation of the mechanical properties of foamed cements when subjected to realistic field temperatures. Since temperature increases by ~25 °C/km in depth, it is important to understand the properties of foamed cements used in wellbore applications at relevant depths. By studying these foamed cements up to around 165 °C, characterization up to ~6 km in depth is achieved, which covers almost all drilling depths. In particular, it was found that foamed cements containing a higher percentage of air were less affected by temperature, and that Young’s modulus and the compressional sound speed do not decrease linearly with the increasing air content, as one might expect. The sound speeds varied from 2942 m/s for 10% foamed cement, to 2500 m/s for 30% foamed cement at room temperature. Young’s modulus varied from 16.0 GPa for 10% foamed cement to 9.2 GPa for 30% foamed cement at room temperature. The softening rate with heating also decreased with the increasing air content, with 10% foamed cement decreasing by 7.8% in Young’s modulus with heating from room temperature to ~165 °C, while 30% foamed cement only decreased by 5.5%.