A method for magnetizing a wellbore tubular includes magnetizing the tubular at three or more discrete locations on the tubular. In exemplary embodiments the magnetized wellbore tubular includes at least one pair of opposing magnetic poles located between longitudinally opposed ends of the tubular. Wellbore...http://www.google.de/patents/US8026722?utm_source=gb-gplus-sharePatent US8026722 - Method of magnetizing casing string tubulars for enhanced passive ranging
