TOT Technologies’ Dual Telemetry EMPULSE allows continuous drilling operations where ground or drilling conditions and technical reasons (such as drilling out of casing) interrupt or prevent data transmission to the surface. Switching from EM to Mud Pulse data transmission, or vice versa, is performed via downlink avoiding costly trips to change out equipment and ensuring that important directional and formation information is always available whatever the down-hole conditions. The system can be pre-programmed at surface enabling the tool to operate in ‘sliding’ and ‘rotary’ modes whilst drilling. This allows for optimal data transmission and update rates and reduces unnecessary power consumption. Other modes may be programmed and switched via downlink for operations such as magnetic ranging. Where used in conjunction with depth tracking the system offers a full suite of LWD sensors including CPR Resistivity, Gamma, Pressure while Drilling, Vibration, ROP and Temperature. EM-PULSE is designed as a modular probe based system with flexible centralizers that are compatible with most drill collar sizes providing a one size fits all solution. In addition the system is also retrievable, an important feature should the drill string becomes stuck in hole.