Hutchins (2005) investigatedthedynamicstabilityandrheol-
ogy offoamscontainingpolymersupto400 °F and2000psiby
using acirculatingloopfoamrheometer.Apowerlawmodelwas
proposed todescribetheeffectiveviscosityoffoams.Foamstabi-
lity andbubbletexturewereaffectedbytheadditives,tempera-
ture, andpressure.Thefoamswith fine andhomogeneousbubble
textureweremoreviscousandstablethanthosewithcoarseand
heterogeneoustexture. Bonilla andShah(2000), Sani etal.(2001),
and Sudhakar (2002, 2003) utilized asimilarcirculatingloop
rheometertoinvestigatetherheologyofGuarfoamsandXanthan
foams. Herschel–Bulkley (HB)modelandpowerlawmodelwere
adoptedtocorrelatetheviscositydata.