Patent ID: 8800655

Claim:
A stage cementing tool comprising: a closing sleeve; an opening and closing sleeve shear means; an opening and closing seat sleeve having a running-in-hole position, an open position, and a closed position, wherein the opening and closing sleeve shear means holds the opening and closing seat sleeve above the closing sleeve such that a differential pressure area is created, wherein the opening and closing seat sleeve isolates port holes during the running-in-hole position when being lowered into a bore hole, wherein the opening and closing sleeve shear means shear after pressure is applied and allow the opening and closing seat sleeve to drop to the closing sleeve such that the opening and closing seat sleeve is in the open position and port holes are open, wherein the opening and closing seat sleeve is used as a mechanical opening and closing seat sleeve when a bomb is dropped into the bore hole and is used as a hydraulic opening and closing seat sleeve when a bomb is not dropped into the bore hole, and the same mechanical parts are used when the opening and closing seat sleeve operates as a mechanical opening and closing seat sleeve as when the opening and closing seat sleeve operates as a hydraulic opening and closing seat sleeve.