Patent ID: 7650269
Filing Date: 2010-01-19
Classification: G01V

Abstract:
1. A method of surveying a well borehole, comprising the acts of: disposing a sensor tool on a downhole segment of a drillstring inserted into said borehole; while said drillstring is rotating in said borehole, obtaining a first set of rotating sensor data from said sensor tool, the first set of data comprising magnetometer data and accelerometer data, the first set of data obtained at a first sample rate, and including data influenced by magnetic fields comprising an ambient magnetic field, a rotation-induced magnetic field, and an ambient-induced magnetic field; obtaining a second set of data from the sensor tool while the sensor tool is stationary, the second set of data comprising magnetometer data and accelerometer data, the second set of data obtained at a second, lower, sample rate; and calculating a trajectory model of said borehole through use of both the first set of data and the second set of data.