Patent ID: 6924646
Filing Date: 2005-08-02
Classification: G01V

Abstract:
1. A method for locating a fracture in an earth formation using a propagation tool disposed in a borehole traversing the formation, the tool having a longitudinal axis, comprising: (a) transmitting electromagnetic energy from a transmitter antenna disposed on the propagation tool with its magnetic moment at an angle with respect to the longitudinal tool axis; (b) measuring voltage signals detected at a plurality of receiver antennas disposed on the propagation tool with their axes at an angle with respect to the longitudinal tool axis and oriented in different directions from one another, the voltage signals being related to the transmitted electromagnetic energy; (c) associating the measured voltage signals with a plurality of azimuthal angles measured circumferentially about the longitudinal tool axis; and (d) shifting at least one of the azimuthal angles associated with at least one of the measured voltage signals by a predetermined angle and processing the shifted and unshifted signals to locate the fracture.