Patent ID: 6922373
Filing Date: 2005-07-26
Classification: G01V

Abstract:
1. A method of determining the relative bearing of a receiver in a borehole comprising the steps of: a. using a directional borehole receiver to receive a direct P-wave generated by a source; b. determining the source azimuth from the source to the borehole; c. estimating an approximate relative bearing angle of the borehole receiver; d. scanning at least one angle around the approximate relative bearing angle; e. rotating for each scanned angle the directional data into the true earth frame creating rotated directional data for each of the scanned angles; f. measuring for each scanned angle a polarization angle of the rotated data in the horizontal plane; g. estimating an azimuth from each polarization angle; h. calculating for all source events the weighted sum of the difference between source azimuth and estimated azimuth, and normalizing by the number of shots to find the azimuth error; and i. selecting a relative bearing angle from the scanned angles.