Patent ID: 6712134
Filing Date: 2004-03-30
Classification: E21B

Abstract:
A jarring tool for opposed jarring directions, comprising:a body: a first piston mounted for relative movement with respect to said body and having a first valve seat; a first valve member assembly movably mounted in said body for selective contact with said first valve seat, said first valve member assembly biased out of contact from said first valve seat by a bias force selectively resulting from a predetermined pressure buildup on said first piston to allow a jarring force to be imparted to said first piston in a first direction; and a second piston mounted for relative movement with respect to said body and having a second valve seat and a second valve member assembly in selective contact with said second valve seat until said bias force acting on said first valve member assembly moves said second valve member assembly out of contact with said second valve seat to allow a jarring force to be imparted to said first piston in a second direction opposite said first direction.