Effect of Silica Flour and Potasium Chloride as Additives in the Rhelogical Properties of High Temperature High Pressure Gas Well Cement Slurry
Amuah Freda Roli *
African Center of Excellence, Center for Oilfield Chemicals and Research, University of Port Harcourt, Port Harcourt, Nigeria.
Ogbonna Joel
African Center of Excellence, Center for Oilfield Chemicals and Research, University of Port Harcourt, Port Harcourt, Nigeria and Department of Petroleum and Gas Engineering, University of Port Harcourt, Port Harcourt, Nigeria.
Anthony John
African Center of Excellence, Center for Oilfield Chemicals and Research, University of Port Harcourt, Port Harcourt, Nigeria and Department of Petroleum and Gas Engineering, University of Port Harcourt, Port Harcourt, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
This study explores the effects of silica flour and potassium chloride on the rheological properties of high temperature and pressure gas wells. Seven different materials were used as additives which includes: fresh water, dyckerhoff, silica flour, antifoam, extender, fluid loss, dispersant, retarder, anti-settling agent, gas control agent, dry viscosifier, potassium chloride and accelerator. Four recipes were prepared using these additives in different mixtures. Recipe four has all the additives including silica flour and potassium chloride. A series of flow tests was performed using an advanced shear-stress/shear strain controlled rheometer. Rheological properties of cement slurries were calculated from the resulting flow curves using the Bingham plastic model and the Herschel–Bulkley’s model. Changes in shear stress–shear rate relationships, yield stress, plastic viscosity, and shear thinning/thickening behavior were found to be related to temperature and the type and dosage of supplementary cementitious material. The four recipes were applied in 10 cases.
Among the four different recipes tested for all the 10 cases, Recipe 4 has the best regression values for both temperature vs transit time and pressure vs transit time this can be attributed to the presence of silica flour and potassium chloride.
Keywords: Additives, slurry, rheology, temperature, pressure