ABSTRACT
Abstrac t A parametri c surve y o f typica l pumpin g condition s i n Nort h Se a wel l cementin g ha s show n tha t althoug h th e flo w o f th e cemen t slurr y ma y occasionall y b e turbulen t i n th e annulus , th e flo w i s generall y lamina r i n th e pip e wit h a plu g diamete r i n exces s o f 70 % o f th e pip e diameter . Thi s pape r examine s th e propertie s o f th e materia l i n th e plu g obtaine d b y measurin g th e 'ge l strength' , define d a s th e stati c yiel d strengt h a t zer o shea r rate , b y th e us e o f a si x blade d shea r vane . Thi s techniqu e ha s th e advantag e o f avoidin g hig h wate r conten t sli p layer s suc h a s ma y for m a t th e surfac e o f smoot h bobs . Th e developmen t o f th e shea r van e techniqu e int o th e hig h pressur e an d hig h temperatur e regim e b y th e us e o f a modifie d pressurize d consistomete r i s described . Dat a ar e presente d showin g th e effec t o f pressure s u p t o 3 6 MP a an d temperature s u p t o 52° c o n th e ge l strengt h an d dynami c yiel d strengt h o f tw o cemen t slurrie s use d i n th e oi l industry . I t i s show n tha t ge l strength s i n exces s o f 15 0 P a ar e measure d b y th e van e tes t afte r fort y minute s o f heatin g an d value s u p t o 200 0 P a ar e observe d afte r sevent y minute s heating . Th e effec t o f pressur e alon e implie s tha t th e slurrie s ma y no t behav e a s full y saturate d undraine d systems . Keyword s Shea r vane , oi l wel l cements , ge l strength , yiel d strength .
