The present invention provides an apparatus in the form of a float shoe or collar for use in cementing a casing string within a well bore. The shoe or collar has blades extending therefrom for centering the shoe or collar, as well as the lower end of the casing string, within the well bore. The blades...http://www.google.fr/patents/US5697442?utm_source=gb-gplus-shareBrevet US5697442 - Apparatus and methods for use in cementing a casing string within a well bore
Apparatus and methods for use in cementing a casing string within a well ...
