Geophone orientation azimuths were found from 3D and 2D VSP data, acquired near Lousana, Alberta, in order to examine any dependence of computed geophone orientation on source-well offset or azimuth. Additionally, a comparison was made between analytic and hodogram methods. The 2D dataset consisted of three lines; the standard deviation for this survey was 0.67° for all lines, 0.45° for the east line, 0.41° for the southeast line and 0.55° for the south line. Removal of sources less than 500 m (approximately 1/2 of the geophone depth) significantly improved the scatter in this dataset. Standard deviation in orientation azimuths for all lines was found to be 0.90° using the hodogram method; thus, while the both methods performed well, the analytic method produced more consistent results. The 3D dataset was divided based on source-well azimuth into bins with centers trending 0°-180°, 45°-225°, 90°-270° and 135°-315°. There appeared to be little dependence on source-well sector azimuth, which is expected for flat, isotropic geology near the well. Standard deviation in orientation azimuths were found to be 1.74° using the full 3D dataset. Offsets were binned into ranges of 0-600 m, 600-950 m, 950-1300 m, 1300-1650 m and greater than 1650 m. Scatter in rotation angles was shown to be strongly dependent on offset, with the most constrained results in the 1300-1650 m offset bin. The optimal offset range for geophone orientation calibration was found to be between 1 and 2 times the receiver depth.
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