Abstract: A bi-directional jar with bit turning capability jars down when weight is set down on the tool and pressure is built up on a piston to move the body up while compressing a spring. When spring force opens the valve in the piston, the housing comes down striking an anvil as the flow rushes through the piston before the valve recluses for another cycle. The valve member features a hydraulic brake to slow its movement after the valve is forced open. Clutching action comes from an angled spline acting through a spirally cut cylinder, which reduces in diameter to engage the bit to turn. A single spring acts on a pair of pistons for bi-directional jarring. Modularity allows rapid conversion to uni-directional operation.

Abstract: A method of removing a gravel packed screen to reach another zone is described. The method involves a bottom hole assembly comprising an isolation device for the screen and a tool to latch on to it. A perforating gun is shot off to put holes in the screen to allow gravel to come through. A flow through a reversing valve is initiated to urge the gravel into the newly perforated screen while a vibrator shakes the screen and stimulates gravel flow through the screen. Alternatively, the screen is not isolated and a reverse circulation from the surface in conjunction with vibration urges the gravel to flow through the screen and out through the tubing supporting the bottom hole assembly.

Abstract: A downhole vibration tool consisting of a body assembly installed in a work string, and a drop-in dart valve assembly. An open inner bore through the body assembly allows the performance of operations through the body assembly. To activate the vibration tool, the dart valve assembly is dropped into the work string and pumped downhole into engagement with the body assembly. Once the dart valve assembly is in place in the body assembly, continued pumping of fluid will cause the tool to begin to vibrate longitudinally. When the jarring operation is finished, the dart valve assembly can be released from the body assembly and retrieved, with a wireline or coiled tubing unit.

Abstract: A bi-directional jar with bit turning capability is disclosed. To jar down, weight is set down on the tool and pressure is built up on a piston to move the body up while compressing a spring. When spring force opens the valve in the piston, the housing comes down striking an anvil as the flow rushes through the piston before the valve recluses for another cycle. The valve member features a hydraulic brake to slow its movement after the valve is forced open. Clutching action comes from an angled spline through a spirally cut cylinder, which reduces in diameter to engage the bit to turn. A single spring acts on a pair of pistons for bi-directional jarring. Modularity allows rapid conversion to uni-directional operation.

Abstract: A method for using fishing and drilling jars which require high applied tensile loads in deviated or horizontal well bores is described. The method involves the placement of the string of high frequency vibratory devices that are triggered by flow therethrough. These vibratory devices are placed in the region of the bend or deviation in the well bore. The vibratory forces are applied coincidently with the tensile overpull force so as to fully utilize the applied overpull force at the surface down hole at the jar which is attached to the fish.

Abstract: A vibratory impact tool for loosening downhole stuck objects in oil or gas wells, utilizing an internal piston spring which is repeatedly compressed by hydraulic pressure, and repeatedly released by lifting a dart valve from a valve seat on a flow-through piston. When the dart valve is lifted from the valve seat by a tripping spring, flow resumes through the piston, quickly lowering hydraulic pressure above the piston, allowing the piston spring to sharply drive the piston against the housing. The dart valve is then reseated on the valve seat, causing the piston to again be driven against the piston spring, rapidly repeating the process.

Abstract: A bypass sub which will automatically bypass fluid flow in excess of a selected optimal flow rate for a downhole mud motor. A spring biased mandrel within a housing is driven downwardly by increased fluid flow, and driven upwardly by spring force upon decreased fluid flow, to control the alignment of a port in the mandrel with a bypass port in the housing, thereby maintaining a desired rate of fluid flow to the downhole motor.