APARELHO E MÉTODO PARA DESENVOLVER UM CENTRALIZADOR INSTALADO EM UMA COLUNA DE REVESTIMENTO EXPANSÍVEL

A method of and apparatus for deploying a bow spring centralizer installed on an expandable casing string and restrained in the collapsed configuration by restraining bands that rupture, upon expansion of the casing string, to deploy the bow spring centralizer and provide stand-off between the expanded casing string and the wall of the borehole. In one embodiment, the bow spring centralizer comprises landings for receiving and retaining the bands for restraining the centralizer in the collapsed configuration. In another embodiment, the bands are secured to the centralizer to prevent separation of the ruptured bands from the deployed centralizer.