Casing centralizer is a cementing tool which applied to centralize casing to improving the cementing quality. The cement could be concreted firmed between casing and borehole wall. They are designed for High Restoring Force and Low Starting Force for centralizing the casing pipe in a Horizontal and Deviated well. Centralizer could be installed on casing joint or any position working with stop collar for centralizing.
Commonly, there are two types casing centralizer of bow spring and rigid, sometimes, there is semi-rigid casing centralizer type. Depends on different circumstances, suitable centralizer is choosen.
As one useful cement tool, rigid centralizer enables casing run easily in wellbore of Horizontal and Deviated well with its shape of stream-lined. The ID of centralizer is bigger than OD of casing. Slip-on centralizer from pin end and tighten up the set screws or fixed with stop collar. There are three kinds of Rigid Centralizer available: roller centralizer, spiral blade rigid centralizer and straight blade centralizer. The material for both kinds of centralizers can be cast steel, cast aluminum, polymer etc.
There are two types of bow spring casing centralizer: Not-welded and welded, which can be single or double bow. For easily installation, hinged centralizer is preferred. After casing is conncected, centralizer can be placed on joint. Otherwise, centralizer should be fixed on designed position of casing with stop collar. Slip-on welded centralizer can be slipped onto casing from pin end then fixed with stop collar.
DCT Bow spring casing centralizer (slip-on one piece type, hinged non-welded type, hinged welded type, slip-on welded type, single bow, double bow)
GFZ Rigid casing centralizer (roller centralizer, spiral blade type, straight blade type, cast steel, cast aluminum, nylon, polymer)