US Patent 11274519 Reverse cementing tool

A reverse cementing tool has an outer case connected in a casing string. A dual stage actuating sleeve is disposed in the outer case and is operable in a first stage actuation to open a cement flow path from a well annulus to a central flow passage of the reverse cementing tool. In a second stage actuation the cement flow path is closed. The actuating sleeve includes inner and outer sleeves in the outer case. The inner and outer sleeves move in opposite directions in the outer case to first open, and then close the cement flow path.