The invention discloses present disclosure provides a centralising device and a method for using the centralising device to immovably centralise a conductor casing within an aperture of a supporting framework. The centralising device has one or more body portions, each having an inner surface and an outer surface, wherein the inner surface(s) are arranged for abutting the conductor casing and the outer surface(s) are arranged for abutting the framework. The body portion(s) are located within the aperture between the conductor casing and the framework for limiting movement of the conductor casing relative to the framework. Each body portion includes a first member providing the outer surface and a second member providing the inner surface. The first member and second member are movable relative to each other, to thereby permit adjusting the position of the inner surface relative to the position of the outer surface, so as to centralise the conductor casing within the aperture.