TELEMETRY - MWD - THE SECOND-TIER BENEFITS.

The Teleco MWD system consists of a sensor and transmitter mounted in a nonmagnetic drill collar (the downhole assembly) and surface display equipment located on the drilling platform. The system uses mud pulse telemetry to transmit data and hence there is no wire line. The downhole assembly is installed in the drill string near the drill bit. The transmitter encodes the directional data into a series of pressure pulses by periodically moving a valve that partially restricts mud flow. The presence or absence of pulses in a given time interval forms a binary number which is decoded into a directional angle and displayed on the surface equipment. Electrical power for the downhole assembly is produced by a mud-powered turbine-generator within the assembly.