Abstract: A centraliser comprises two collars that are connected by asymmetric spring bows. The spring bows each comprise two arcs, where the curvature of one arc is inverted with respect to the curvature of the other arc, one being concave and the other convex. The spring bows are in sets that are equidistantly spaced around the circumference of the collars, each set having the same configuration, and the opposite configuration to the spring bows in the other set. Upon insertion into a wellbore, one set of spring bows is therefore compressed before the other set. Upon compression, the deformation of the concave arc leads to mutual deformation of the convex arc, and the spring bows adopt a flatter configuration, enhancing the rotational freedom of the tubular.

Abstract: A centralizer comprises two collars that are connected by asymmetric spring bows. The spring bows each comprise two arcs, where the curvature of one arc is inverted with respect to the curvature of the other arc, one being concave and the other convex. The spring bows are in sets that are equidistantly spaced around the circumference of the collars, each set having the same configuration, and the opposite configuration to the spring bows in the other set. Upon insertion into a wellbore, one set of spring bows is therefore compressed before the other set. Upon compression, the deformation of the concave arc leads to mutual deformation of the convex arc, and the spring bows adopt a flatter configuration, enhancing the rotational freedom of the tubular.

Abstract: A centraliser comprises two collars that are connected by asymmetric spring bows. The spring bows each comprise two arcs, where the curvature of one arc is inverted with respect to the curvature of the other arc, one being concave and the other convex. The spring bows are in sets that are equidistantly spaced around the circumference of the collars, each set having the same configuration, and the opposite configuration to the spring bows in the other set. Upon insertion into a wellbore, one set of spring bows is therefore compressed before the other set. Upon compression, the deformation of the concave arc leads to mutual deformation of the convex arc, and the spring bows adopt a flatter configuration, enhancing the rotational freedom of the tubular.