Patent ID: 7090020
Filing Date: 2006-08-15
Classification: E21B

Abstract:
1. A method for controlling downhole operation of a multi-cycle dump valve mechanism of a straddle packer tool within a well casing, said multi-cycle dump valve mechanism having a valve operating mandrel movable within a housing and supporting a dump valve element for open and closed positioning relative to a valve seat of said housing, an indexing mechanism controlling closing movement of said valve operating mandrel and an energy storage system, said method comprising: positioning the straddle packer tool and multi-cycle dump valve mechanism at a desired location within a well casing and with said valve operating mandrel of said dump valve mechanism at a starting position with said dump valve element open; causing flow responsive conditioning of said indexing mechanism for closing movement of said valve operating mandrel and said dump valve element; causing flow responsive dump valve closing movement of said valve operating mandrel and storing energy in said energy storage system during said flow responsive valve closing movement with said dump valve element closed with respect to said valve seat, causing the flow of fluid through the straddle packer tool and accomplishing well treatment; upon completion of well treatment, causing stored energy return of said valve operating mandrel to an intermediate valve open position causing dumping of fluid through said dump valve mechanism into the well casing; and with said energy storage system returning said valve operating mandrel to said starting position.