STANDARD HANDBOOK OF PETROLEUM & NATURAL GAS ...

MWD and LWD 931
The cone can be replaced by a mechanism that senses the angular position
rather than the inclination of the drillstring.
The tool is then sensitive to the tool face and is called the teleorienter.
Figure 2-241 shows the read-out display of the driller in a zero tool-face
position. Four mud pressure pulses will be recorded each time the pumps are
started. In Figure 4-242a, a tool-face value of 20" is indicated by three pulses,
turning to the right. In Figure 4-24213, a tool-face value of -20" is indicated by
five pulses, and the borehole is turning left.
f.;;;\
HOLE
Figure 4-241. Driller read-out display of the teleorienter in a zero tool face
angle "go straight, build angle" position. (Courtesy Teledrift, Inc. [104].)
Figure 4-242. Driller read-out display of the teleorienter: (a) +20° tool-face
angle, turning right position; (b) -20" tool-face angle, turning left position.
(Courtesy Teledrift, Inc. [ 1 041.)