Abstract: A servo valve in a servo pulser used to restrict flow to a larger main valve includes external stops on a housing to define rotational starting/stopping points and sweep zones for a servo rotor having digits for contacting the stops. The digits extend longitudinally away from the servo valve seat and extend into the sweep zones. Interaction between the stops and the digits in the sweep zones limit rotation of the rotor to a swept arc between the stops. The servo pulser rotor oscillates between stopping points in alternating clockwise/counterclockwise sweeps. Each sweep in a given direction creates one full pulse: closed, open, and closed. The servo pulser carries out a feedback/decision loop between hydraulic pulses (and sweeps) that receives information on one or more previous pulses and calculates how fast or slow it should drive the servo rotor for the current pulse.

Abstract: A servo valve in a servo pulser used to restrict flow to a larger main valve includes external stops on a housing to define rotational starting/stopping points and sweep zones for a servo rotor having digits for contacting the stops. The digits extend longitudinally away from the servo valve seat and extend into the sweep zones. Interaction between the stops and the digits in the sweep zones limit rotation of the rotor to a swept arc between the stops. The servo pulser rotor oscillates between stopping points in alternating clockwise/counterclockwise sweeps. Each sweep in a given direction creates one full pulse: closed, open, and closed. The servo pulser carries out a feedback/decision loop between hydraulic pulses (and sweeps) that receives information on one or more previous pulses and calculates how fast or slow it should drive the servo rotor for the current pulse.

Abstract: A shock isolated gamma probe attenuates axial, lateral, and torsional shocks to a gamma sensor package. A gamma sensor is inserted into and fixed to a tubular cartridge. The cartridge is closed with a cap and keyed at the other end. The cartridge is inserted into a resilient sleeve having an extension at the closed end to conform to the key on the cartridge. The open end of the resilient sleeve is closed with a gasket. The sleeve/cartridge assembly are inserted into a tubular structure on a first chassis. The first chassis has a keying structure for the key and extension of the resilient on an end bulkhead. The cartridge and first chassis are resiliently engaged to attenuate shocks. A second bulkhead, on a second chassis, closes the open end of the tubular structure on the first chassis.

Abstract: A shock isolator device for use in a downhole tool attenuates axial shocks to a protected structure and maintains that structure's rotational orientation to the tool while reducing damage to, maintenance costs of, and wear on, the device components. The shock isolator device interposes an internally- and externally-splined key between an internally-splined sleeve on an anti-rotation section and an externally-splined plunger attached to a connector. The key is less wear-resistant than the sleeve or plunger and can be replaced. The meshed sleeve, key, and plunger force the protected structure attached to the connector to maintain its rotational orientation. The sleeve of the anti-rotation system is attached to a shock damper, which damps axial shocks between the plunger and the sleeve, and is connected to a second connector. The shock damper includes a spring assembly and a viscous damper using a piston in an oil-filled cylinder forcing oil through an orifice.

Abstract: An asynchronous top-mounted pulser system for a measurement while drilling tool uses hydraulic flow, an obstruction, a piston-balance system, and an orifice, to create pressure pulses in drilling fluid, using hydraulic pressure on an obstruction in a main pulser to assist in closing the obstruction. A valve poppet is set above (upstream of) the orifice and is pushed by fluid flow towards a closing position. The piston-balance system, connected to the poppet and located downstream of the orifice in the main pulser, responds to net pressures on the upstream and downstream sides of the piston to move the poppet. The piston also responds to a spring assembly urging the piston downstream, and tending to move the valve poppet to a closed position. A servo pulser, located downstream of the main pulser, opens and closes a rotary shear servo valve-controlled bypass flow path to control the net pressures on the piston.

Abstract: An asynchronous top-mounted pulser system for a measurement while drilling tool uses hydraulic flow, an obstruction, a piston-balance system, and an orifice, to create pressure pulses in drilling fluid, using hydraulic pressure on an obstruction in a main pulser to assist in closing the obstruction. A valve poppet is set above (upstream of) the orifice and is pushed by fluid flow towards a closing position. The piston-balance system, connected to the poppet and located downstream of the orifice in the main pulser, responds to net pressures on the upstream and downstream sides of the piston to move the poppet. The piston also responds to a spring assembly urging the piston downstream, and tending to move the valve poppet to a closed position. A servo pulser, located downstream of the main pulser, opens and closes a rotary shear servo valve-controlled bypass flow path to control the net pressures on the piston.

Abstract: An asynchronous top-mounted pulser system for a measurement while drilling tool uses hydraulic flow, an obstruction, a piston-balance system, and an orifice, to create pressure pulses in drilling fluid, using hydraulic pressure on an obstruction in a main pulser to assist in closing the obstruction. A valve poppet is set above (upstream of) the orifice and is pushed by fluid flow towards a closing position. The piston-balance system, connected to the poppet and located downstream of the orifice in the main pulser, responds to net pressures on the upstream and downstream sides of the piston to move the poppet. The piston also responds to a spring assembly urging the piston downstream, and tending to move the valve poppet to a closed position. A servo pulser, located downstream of the main pulser, opens and closes a rotary shear servo valve-controlled bypass flow path to control the net pressures on the piston.

Abstract: An asynchronous top-mounted pulser system for a measurement while drilling tool uses hydraulic flow, an obstruction, a piston-balance system, and an orifice, to create pressure pulses in drilling fluid, using hydraulic pressure on an obstruction in a main pulser to assist in closing the obstruction. A valve poppet is set above (upstream of) the orifice and is pushed by fluid flow towards a closing position. The piston-balance system, connected to the poppet and located downstream of the orifice in the main pulser, responds to net pressures on the upstream and downstream sides of the piston to move the poppet. The piston also responds to a spring assembly urging the piston downstream, and tending to move the valve poppet to a closed position. A servo pulser, located downstream of the main pulser, opens and closes a rotary shear servo valve-controlled bypass flow path to control the net pressures on the piston.

Abstract: An adjustable hydraulic coupling device allows simultaneously mounting of different parts of a downhole drilling tool to the drill string near its upper and lower extremities. This top- and bottom-mounting is made to points on the drill string separated by an indeterminate length. The coupling device allows a mechanical and sealed fluid connection between two portions of the tool, and allows assembling of both portions of the drilling tool into one functional unit, and allows both axial translation and rotational motion therebetween. A cylindrical protruding tube is attached to the portion of the drilling tool mounted at its upper extremity while a mating cylindrical tube is attached to the part of the drilling tool mounted near the bottom. During assembly, the smaller tube enters the larger tube and provides a sealed fluid path and also allows for the engagement length of the assembly to vary as required.

Abstract: A servo pulser used to actuate a pulser valve and create pressure pulses in downhole measurement while drilling tools is described. An electric gearmotor is used to rotate a shaft which in turn operates a servo valve. A facing portion of the shaft is compressed onto the face of a servo seat having passages connected to the inside of a drill collar and the rotating action is used to open and/or obstruct a fluid path through those passages. The shaft may include wear-resistant tips to obstruct the fluid path. Part of the torque-transmitting apparatus between the gearmotor and the shaft can be hydrostatically compensated, and part sealed against the operating environment. A magnetic torque coupler may be used as part of the torque-transmitting apparatus between the gearmotor and the shaft. The servo pulser is coupled to a pulser valve, a power source and a sensor package all of which reside inside a short section of drill pipe near the bottom of well bore being drilled.

Abstract: A servo pulser used to actuate a pulser valve and create pressure pulses in downhole measurement while drilling tools is described. An electric gearmotor is used to rotate a shaft which in turn operates a servo valve. A facing portion of the shaft is compressed onto the face of a servo seat having passages connected to the inside of a drill collar and the rotating action is used to open and/or obstruct a fluid path through those passages. The shaft may include wear-resistant tips to obstruct the fluid path. Part of the torque-transmitting apparatus between the gearmotor and the shaft can be hydrostatically compensated, and part sealed against the operating environment. A magnetic torque coupler may be used as part of the torque-transmitting apparatus between the gearmotor and the shaft. The servo pulser is coupled to a pulser valve, a power source and a sensor package all of which reside inside a short section of drill pipe near the bottom of well bore being drilled.