Permanent downhole resonant source
Pilot operated mud pulse valve and method of operating the same
Power transmission apparatus for enclosed fluid systems
Pressure pulse detection apparatus
Pressure pulse detection apparatus incorporating noise reduction
Pressure pulse generator for downhole tool
Pressure pulse generator for measurement-while-drilling...
Pressure pulse generator system for measuring while drilling
Pressure signalling for fluidic media
Process and device for transmitting information over a distance
Pulse production and control in drill strings
Pulser