METHOD OF AND APPARATUS FOR TELEMETERING INFORMATION FROM A POINT IN A WELL BOREHOLE TO THE EARTH'S SURFACE

Down-hole information from rotary well drilling operations is transmitted to a surface or remote location by the venting of drilling fluid from the interior of the drill stem into the bore-hole annulus in, for example, Binary Coded Decimal format. A valve is caused to operate by the digital output of one or more down-hole transducers thus releasing and restoring the drilling fluid pressure in the desired sequence. A "sub" contains the necessary electronics, power supply and a motorized valve assembly. Commands from the surface to transmit information from any one of the transducers are transmitted by means of sequential pulses such as Binary Coded Decimal format, in the drilling fluid pressure which are provided by the operator by deliberately decreasing and then increasing the surface pump pressure in a sequence to which the applicable down-hole actuating means is responsive.