Apparatus for drill stem testing

Claim 1

APPARATUS FOR USE IN DRILL STEM TESTING AN ISOLATED EARTH FORMATION IN FLUID COMMUNICATION WITH THE INTERIOR OF A DRILL STEM THROUGH THE LOWER END THEREOF FOR INDICATING THE PRESENCE OF EARTH FLUIDS IN THE DRILL STEM, COMPRISING: AN ELONGATED HOUSING; SWAB CUP MEANS ON SAID HOUSING HAVING A DIAMETER SUFFICIENT SO THAT SAID SWAB CUP MEANS SEALINGLY CONTACT THE BORE WALL OF THE DRILL STEM; A FLUID PASSAGWAY MEANS INCLUDING A CHECK VALVE IN SAID HOUSING, IN FLUID COMMUNICATION WITH THE EXTERIOR OF SAID HOUSING ABOVE AND BELOW THE SWAB CUP MEANS, ADAPTED TO PERMIT ONE-WAY FLUID FLOW UP THE DRILL STEM PAST SAID SWAB CUP MEANS; AN ELONGATED MANDREL ADAPTED TO BE CONNECTED TO A WIRELINE, AND TELESCOPICALLY EXTENDING INTO SAID HOUSING THROUGH ONE END OF SAID HOUSING P A LATCHING HEAD AFFIXED TO ONE END OF SAID MANDREL; STOP MEANS ON THE HOUSING ENGAGEABLE BY SAID LATCHING HEAD TO HOLD SAID MANDREL WITHIN SAID HOUSING AT ITS LEAST TELESCOPED POSITION: A TRIPPABLE LATCH IN SAID HOUSING INITIALLY LATCHED ON TO SAID LATCHING HEAD TO HOLD SAID MANDREL IN ITS MOST TELESCOPED POSITION; LATCH TRIPPING MEANS, INCLUDING ELECTROMAGNET MEANS IN SAID HOUSING OPERATIVELY ASSOCIATED WITH SAID TRIPPABLE LATCH TO TRIP SAID LATCH WHEN SAID ELECTROMAGNET MEANS IS ELECTRICALLY ENERGIZED; ELECTRICAL RESISTIVITY DETECTING MEANS ON SAID HOUSING ADAPTED TO MEASURE THE RESISTIVITY OF FLUIDS AROUND SAID HOUSING AND TO PRODUCE AN ELECTRICAL OUTPUT SIGNAL INDICATIVE OF THE MEASUREMENT; AND MEANS ELECTRICALLY CONNECTING SAID ELECTRICAL RESISTIVITY MEASURING MEANS TO SAID ELECTROMAGNET MEANS OPERABLE TO ENERGIZE SAID ELECTROMAGNET MEANS WHEN THE OUTPUT SIGNAL OF THE RESISTIVITY MEASURING MEANS IS INDICATIVE OF FLUIDS OF GIVEN RESISTIVITY AROUND SAID HOUSING.