The Flow Characteristics of Fly Ash Slurry for Plugging Abandoned Wells Using Coiled Tubing

The utilization of fly ash has been researched widely in recent years because of the environmental and economical concerns. The primary importance of plugging to abandon wells is to prevent contamination of groundwater aquifer by surface water, oil or gas seepage, or brine formation below the groundwater aquifers. Cement is the present plugging material. However, cement can be replaced by Class C fly ash which has more cementitious material than Class F fly ash due to its higher lime content. In this paper, the fly ash slurry properties are investigated in the laboratory experiments. Thickening times are measured to estimate the needed pumping time for the fly ash slurry. The rheology of fly ash slurry is also investigated to check the fly ash slurry properties. Finally, the frictional pressure loss test is performed through coiled and straight tubing and the friction pressure loss data are reported.