Patent ID: 6062324
Filing Date: 2000-05-16
Classification: E21B

Abstract:
A well tool apparatus for use with an elongated pipe string that can load the tool transmitting impact thereto and with a flow bore for transmitting pressurized fluid to the tool and wherein the tool can be used during drilling, jarring or impacting in a well bore, comprising:a) a tool housing having an upper end portion connectable to said tool housing and in fluid communication with the lower end of a pipe string, the housing having at least one fluid chamber therein for receiving pressurized fluid transmitted from the pipe string thereto;b) a tubular stem having a flow channel therethrough communicating with the fluid chamber, the stem telescopically received by said housing for relative reciprocal movement therewith between a first unloaded position and a second loaded position, the stem having a valve seat thereon;c) an impact receptive working member attached during use to one end of said tubular stem for movement therewith between said first and second positions, wherein impact is transmitted to the working member in the second impact position so that the working member can be used during drilling, jarring or impacting in the well bore;d) a valve carried in said housing for controlling the flow of pressurized fluid in the fluid chamber, said valve being reciprocally movable therein between first and second positions;e) said valve being operable to relieve fluid pressure within the fluid chamber responsive to predetermined movement of said stem relative to said housing, permitting relative movement of said stem and housing into said second position when the valve seals the valve seat; andf) a shock absorbing member positioned within the fluid chamber and in between the working member and tool housing for reducing stresses in the working member and tool housing that are generated during impact.