Patent attributes
A cementing tool has an outer housing defining a central flow passage and a plurality of housing flow ports through a wall thereof. An opening sleeve has first and second opening sleeve faces exposed to housing pressure. The first opening sleeve face has a greater surface area than the second opening sleeve face. The pressure differential created is such that the sleeve will move from a first position to a second position in which flow through the plurality of housing flow ports is permitted. The cementing tool has an opening seat defined on the opening sleeve. The opening sleeve may also be moved from the first to the second position as a result of the engagement of the opening plug with the opening seat and an application of pressure thereabove.
