Background: Properly designed slurries for optimal cementing operations in oil and gas wells require additives to control properties such as density, free fluid, compressive strength, rheology, among others. These additives are imported though Ghana produces large amount of agro-waste annually and could be enhanced as cement slurry additives. The extender is one of such additives.

Objective and Method: This paper evaluates the effect of guinea corn husk ash as an extender on the properties of class G cement slurries using API RP10B standards. Prepared slurry samples were subjected to rheological, free fluid and density tests and the compressive strength of cured mould were determined.

Results and Conclusion: The ash showed improvement in the compressive strength with all the samples recording values above the minimum 10.3 MPa recommended by API RP10B. The rheological properties recorded viscosity values below 50 cP confirming the good pump-ability of the slurries. The decrease in free fluid content as concentration of ash was increased is indicative of the potentials of the ash to ensure stability of the slurry during cementing operations. The guinea corn husk ash, a product developed from agro-waste showed potential properties of an oil-well cement slurry extender and requires further research.