Precision connector for well instrumentation

Abstract

For the directional drilling of boreholes, the orientation of accelerometer modules, magnetometer modules and gyroscopes or other directional sensing devices must be accurately known and maintained with respect to each other and to external mounting devices. This is accomplished by a self-aligning segmented cylindrical connection which accurately maintains modules in rotational alignment with each other for all three directions of rotation, even if the mating surfaces of the connection experience wear due to rough use in the drilling application or repeated calibration in a calibration fixture. Wedged surfaces on each of the male and female portions of the connection constitute the mating surfaces, and are the only surfaces at which the male and female portions contact one another. A depression between the mating surfaces defined by the female portion permits reproducible angular displacement of one portion with respect to the other even if one or both portions are worn. The connection has great ability to resist relative rotation of the two segments being connected under the application of a bending force because the connection, by its unique design, translates bending load into tensile load with respect to the screws which fasten the connection together.