Abstract: A signature element is attached to a downhole cable or other protected equipment and the signal from a signature position detector is used, at least in part, to control the orientation of a directed perforating device or other directional device. Signal emitting sources can include a radioactive material added to an encapsulating composition of a downhole cable.

Abstract: A signature element is attached to a downhole cable or other protected equipment and the signal from a signature position detector is used, at least in part, to control the orientation of a directed perforating device or other directional device. Signal emitting sources can include a radioactive material added to an encapsulating composition of a downhole cable.

Abstract: A method and apparatus for perforating a casing in a wellbore wherein the casing has control means attached thereto, which method and apparatus includes inserting a detectable source with the control means extending a selected length of the control means; inserting a sensing means in the casing for sensing the detectable source; sensing the location of the detectable source at selected levels in the casing; recording the direction of the detectable source at the selected levels in the casing; inserting perforating means in the casing, the perforating means for perforating the casing, the perforating means having orienting means for selectively positioning the perforating means relative to the recorded direction of the detectable source at the selected levels in the casing; and perforating the casing at a selected orientation relative to the sensed detectable source at the selected levels in the casing.