INERTIALLY-STABILIZED MAGNETOMETER MEASURING APPARATUS FOR USE IN A BOREHOLE ROTARY ENVIRONMENT

摘要

A measurement apparatus for making magnetic and gravity component measurements in a borehole, including measurements made while the apparatus is rotating about the borehole axis, comprising a magnetic field component sensing device having at least two axes of sensivity normal to each other, a gravity field component sensing device having at least two axes of sensitivity normal to the borehole axis and normal to each other, an inertial angular rotation sensing device having an axis of sensitivity along the borehole axis to sense inertial angular motion about the borehole axis, control, power and processing circuitry to operate said sensing devices and to process the outputs of said sensing devices to obtain stabilized component data in a coordinate system that does not rotate with the said measurement apparatus, communication circuitry to transmit output data to auxiliary equipment at the surface or in the borehole, and support structure to support the sensing devices.