Means for perforating and fracturing earth formations

Claim 1

APPARATUS FOR PERFORATING AND FRACTURING A LOW PERMEABILITY EARTH FORMATION PENETRATED BY A TUBULAR WALL CASING COMPRISING, A FLUID CONVEYANCE TUBE WITHIN SAID CASING AND OPENING INTO THE PORTION THEREOF WITHIN THE LOW PERMEABILITY EARTH FORMATION, A SEALING MEANS INTERPOSED BETWEEN SAID TUBE AND SAID CASING TO FORM A SEALED COMPARTMENT IN THE PORTION OF THE CASING IN SAID EARTH FORMATION, FLUID INJECTION MEANS CONNECTED TO SAID TUBE TO INJECT FLUID THROUGH SAID TUBE AND INTO SAID COMPARTMENT TO PROVIDE A PRESSURE THEREIN IN EXCESS OF FRACTURING PRESSURE, VALVE MEANS IN THE PORTION OF SAID TUBE LOCATED WITHIN THE COMPARTMENT CONSTRUCTED SO AS TO PERMIT FLOW ONLY INTO SAID COMPARTMENT WHEREBY PRESSURIZED FLUID MAY BE CONSTRAINED WITHIN SAID COMPARTMENT; A CASING AND EARTH FORMATION PERFORATOR WITHIN SAID COMPARTMENT, AND SAID APPARATUS INCLUDING PRESSURE BLEED-OFF MEANS CONNECTING THE INTERIOR OF SAID COMPARTMENT WITH THE EXTERIOR THEREOF.