Patent ID: 8746343

Claim:
A wellbore fluid treatment assembly comprising: a tubing string including an inner bore and a tubular housing with a wall, an outer wall surface and an inner wall surface defining the inner bore through the tubular housing, the tubing string further including an uphole drift diameter uphole of the tubular housing; a port through the wall of the tubular housing, the port providing access between the outer wall surface and the inner wall surface through the port; a sliding sleeve installed in the tubular housing inner bore and slidable between (i) a closed-port position covering the port, wherein fluid cannot pass through the port, and (ii) a open-port position exposing the port to the inner bore and wherein fluid can pass through the port, the sliding sleeve including an outer diameter, an inner diameter defining an axial bore and a constriction along the inner diameter forming a seat; and a plug moved by fluid pressure through the tubing string and sized to seal against the seat to drive the sliding sleeve from the closed-port position to the open-port position by fluid pressure; wherein the seat is retrievable up through the tubular housing and axially moved up through the inner bore to remove the constriction from the tubing string.