Method and apparatus for surveying a borehole with a rotating sensor package

A method of surveying a well borehole penetrating earth formations, 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 both magnetometer data and accelerometer data, and obtained at a first sample rate;
• 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
• correlating the first and second data sets to estimate the trajectory of said borehole through the formations.

A method of surveying a well borehole, comprising the acts of:

• disposing a sensor tool on a drillstring inserted into said borehole;
• while said drillstring is rotating in said borehole, obtaining a first set of sensor data from at least one inclinometer and at least one magnetometer, the data including data influenced by magnetic fields comprising at least an ambient magnetic field and a rotation-induced magnetic field;
• correcting the first set of sensor data based upon modeling of the rotation-induced magnetic field, to provide a corrected set of sensor data;
• modeling the borehole path in reference to the corrected set of sensor data;
• while the drillstring is not rotating in the borehole, obtaining a second set of data, the second set of data obtained from at least one inclinometer and at least one magnetometer;
• and
• adjusting the borehole path model in reference to the second set of data.

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;
• determining a model that comprises the current that would be induced in a drillstring immersed in a time-varying magnetic field as a result of rotation of the drillstring in a borehole;
• obtaining a set of rotating sensor data from said sensor tool while the drillstring is rotating in said borehole;
• and
• modeling the borehole trajectory in reference to both the modeled induced current and the rotating sensor data;