Triaxial behavior of a stabilized and a highly porous oil well cement paste at different saturation and drainage conditions

Chemo-Physico-Mechanical Behavior of Class G Oil Well Cement Pastes

“…The entrained air resulted in increased porosity of the cement, and also a reduction in the compressive strength of the samples, as exhibited in both UCA measurements and direct uniaxial measurements. A similar correlation between porosity and unconfined compressive strength has been observed previously [59,138]. Addition of a defoamer additive effectively mitigated this behavior in formulations with PVOH, and produced a stabilized cement with a porosity and compressive strength comparable to that of the reference sample.…”

“…Foaming tendency depends on many factors but is increased at low temperatures, in the presence of salts and in the presence of additives that contain surface-active agents such as latex additives or PVOH additives, such as the one chose to be used as fluid loss in this work [59]. Therefore, defoamer agents either decrease the surface tension or alter the dispersion of solids or both [58].…”

“…The low permeability of the cement samples prevented the determination of pore volume. Thus, caliper measurements were used to calculate the porosity using grain volume and total sample volume, as per Lima et al [59].…”