Patent ID: 6296058
Filing Date: 2001-10-02
Classification: E21B

Abstract:
Apparatus for use in a well bore for cleaning perforations traversing earth formations containing hydrocarbons under pressure and having a tubing string extending to a location proximate to the perforations and sealed with respect to the bore of the well; said apparatus includingan implosion tool having selectively operable latching means for releasably locking the implosion tool in the tubing string,said implosion tool having a longitudinally extending flow passage;access ports in said tool for placing said flow passage in fluid communication with the exterior of the tool,a slidable valve sleeve disposed in said flow passage over said access ports and being pressure balanced in said flow passage, said access ports and said valve sleeve constituting an implosion valve;a large piston and a small piston slidably disposed in bores in said tool where the large piston is cooperable with said valve sleeve and the smaller piston is cooperable with said large piston, said large piston being in fluid communication with said flow passage and said small piston being in fluid communication with the formation pressure below the tool, said large piston and said small piston having an area relationship so that a predetermined tubing pressure with respect to a given shut in pressure can be used in moving said valve sleeve and in opening said access ports, and whereby said valve sleeve can be moved to open said access ports by controlling the pressure in the tubing string with respect to the shut in pressure of the well to develop an implosion fluid flow from the perforations when said access ports are first opened.