Offshore cementing operations may require the use of liquid additives for logistical and blending requirements. Some additives should be suspended in hydrocarbon fluid because the active material cannot be readily liquefied in water. These suspensions often exhibit rheological instability and high viscosity, posing issues with shelf life and dosing through delivery lines. This paper describes the use of an innovative liquid cement additive designed to overcome limitations of conventional oil-based suspensions and improve cementing operations.
The new microemulsion fluid loss additive overcomes shelf-life stability and fluid transfer issues inherent to conventional oil-based suspension additives, while providing excellent fluid loss control in cement. Shelf-life stability and fluid transfer rates affect the quality of mixing cement slurry, reduce delivery/pump rates, and extend overall job times. The microemulsion fluid loss additive chemistry was verified to provide improved shelf-life stability and reduced viscosity. Fluid loss, mixability/rheology, and stability tests in cement slurry evaluated the additive performance. Flow tests and calibrations using conventional liquid additive injection pumps were performed before deployment. Benefits of the microemulsion fluid loss additive were validated in a cement design for deepwater offshore work.
