MWD is a wireless measurement while drilling system powered by a downhole turbine generator. The instrument is based on a fixed encoding of the downhole parameters measured by the probe sensor to generate a pulse signal that controls the pulse generator to expand and contract In order to control the mud circulation area between the mushroom head and the restrictor ring. When the mushroom head retracts, the mud in the drill string can smoothly pass through the restrictor ring: when the mushroom head is raised, the mud circulation area is reduced, thereby generating a positive mud pressure pulse in the drill string. The pressure sensor connected to the riser converts the received pressure signal into an electrical signal. It is transmitted to the computer through the explosion-proof box and interface box. The signal is filtered, decoded, and calculated to obtain the downhole measurement parameters.
The mud flow area between the mushroom head and the restrictor ring determines the strength of the signal. The use of different restrictor rings can make the instrument work in different wellbore, different displacement and different working conditions. Obtain a pressure signal of ideal amplitude.
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