Tartan’s At Bit Sub enables measurement of inclination and gamma count data approximately two feet behind the drill bit. Data is wirelessly transmitted around the downhole motor to the Electric Dipole System. Received data is decoded by the Electric Dipole electronics, where it is logged and periodically transmitted to the surface.
The 5.125-in. (130 mm) sub has four packets, one each for inclinometer, gamma, transmission electronics and battery. The 6.5-in. (165 mm) sub has five packets, with the same contents as the 5.125-in. subs, but with an extra battery. Battery life is typically between 8-120 hours per single battery pack.