Well perforating control

Claim 1

IN COMBINATION, A WELL TUBING STRING HAVING A NUMBER OF MAGNET CARRYING NIPPLES AT SPACED APART DEPTH INTERVALS AND WITH POLE PIECES SPACED APART IN CODED RELATION TO DIFFERENT WELL TOOLS TO BE ACTUATED IN RESPONSE TO RECEIPT THEREBY OF MAGNETIC LINES OF FORCE, ONE OF SAID NIPPLES HAVING ITS MAGNET POLE PIECES LOCATED FOR THE PRESENTATION OF LINES OF FORCE ONLY IN AN ISOLATED SIDE REGION OF THE NIPPLE, A PERFORATING GUN FOR CO-OPERATION WITH THE LAST MENTIONED NIPPLE, A MEGNETO DEVICE CONTAINED IN THE GUN AND PROVIDED WITH POLE PIECES ISOLATED WITHIN ONE SIDE OF THE GUN TO COMPEL A GIVEN ROTATIONAL POSITION OF THE GUN FOR INFLUENCING SAID DEVICE BY THE MAGNETIC LINES OF FORCE THROUGH ALIGNMENT OF THE POLE PIECES OF THE GUN AND THE NIPPLE, MEANS OPERABLE ON THE GUN AND CONTROLLING SAID GIVEN ROTATIONAL POSITION AND PRFORATING MEANS RESPONSIVE TO SAID MAGNETO DEVICE AND MOUNTED BY THE GUN TO PERFORM A PERFORATING OPERATION WITHIN A ZONE FIXED IN RELATION TO THE ISOLATED SIDE LOCATION OF THE POLE PIECES OF SUCH MAGNETO DEVICE.