What is the role of mud logger in the petroleum corporations?

Mudlogging is: Real time well site information service, including  :

Monitoring of all drilling parameters (ROP, Mud pit level changes, Variations in total gas,…)

rock cuttings examination and description / Coring

Oil and gas show detection and interpretation

So the Mud logger provides the basic engineering to prevent critical situations in the well and participates in reducing both the cost and the time of drilling

mud logger to pump mud into hole and examine if it need oil base mud or water base mud and then examine cuttings that came into shale shaker 

to pump cement in cementing operations

THE EXAMINATION OF THE ROCK CUTTINGS AND THE PERCENTAGES OF GAS HYDRATES ARE NOTED DOWN BY THE MUD LOGGER. A MUD LOGGER IS VERY ESSENTIAL IN PETROLEUM INDUSTRY AND THE FIRST ONE WHO DETECTS THE PRESENCE OF PETROLEUM.