Tubular testing apparatus with expandable back-up members and method of using same

Claim 1

APPARATUS ADAPTED TO BE CONNECTED TO A TUBULAR STRING FOR HYDRAULICALLY TESTING A TUBULAR MEMBER DISPOSED IN A WELL BORE AT ANY DESIRED PRESSURE, INCLUDING: AN ELONGATE BODY SUPPORTED FROM THE END OF SAID STRING; A FIRST UPPER PACKER AND A SECOND LOWER PACKER SUPPORTED IN LONGITUDINALLY SPACED RELATIONSHIP ON SAID BODY FOR SEALING WITH THE INTERIOR SURFACE OF SAID TUBULAR MEMBER, SAID BODY HAVING PASSAGE MEANS FORMED THEREIN FOR CONDUCTING FLUID FROM SAID STRING TO THE SPACE BETWEEN SAID PACKERS, SAID PACKERS BEING FORMED OF A RESILIENT MATERIAL THAT COLD-FLOWS ABOVE A PREDETERMINED PRESSURE, SAID FIRST PACKER BEING LONGITUDINALLY MOVABLE RELATIVE TO SAID BODY, WITH SAID SECOND PACKER BEING HELD AT A FIXED POSITION THEREON; FIRST RADIALLY EXPANDABLE BACK-UP MEANS MOUNTED ON SAID BODY ABOVE SAID FIRST PACKER, SAID FIRST BACK-UP MEANS NORMALLY BEING SEPARATED FROM THE INTERIOR SURFACE OF SAID TUBULAR MEMBER BY AN ANNULUS-SHAPED SPACE; MEANS FOR RADIALLY EXPANDING SAID FIRST BACK-UP MEANS INTO CONTACT WITH THE INTERIOR SURFACE OF SAID TUBULAR MEMBER WHEN THE FLUID IN SAID SPACE BETWEEN SAID PACKERS IS SUBJECTED TO A PRESSURE GREATER THAN SAID PREDETERMINED PRESSURE; A PLURALITY OF ARCUATE SEGMENTS OF TONGUE AND GROOVE CONSTRUCTION THAT ENCIRCLE SAID BODY BELOW SAID SECOND PACKER, WHICH SEGMENTS HAVE DOWNWARDLY EXTENDING CAM FACES FORMED THEREON; A PRESSURE PLATE THAT ABUTS AGAINST THE LOWER END OF SAID SECOND