US Patent 12000234 Cement plug system

A plug system includes a lower plug, an upper plug, and a sleeve configured to be positioned at least partially within the lower plug, the upper plug, or both. The sleeve defines one or more channels in an outer surface thereof. The sleeve is configured to shift axially from a first position into a second position with respect to the lower plug. In the first position, fluid is prevented from flowing through the one or more channels. In the second position, the fluid is permitted to flow through the lower plug via the one or more channels.