Farshid Madanifar - Master of Science in Petroleum Engineering, Omidieh Branch, Omidieh, Iran
Bahram Habib Nia - Department of petroleum Engineering, Put, Ahwaz, Iran
Babak Karimpour - Bachelor of Science in Mechanical engineering, University of Guilan, Rasht, Iran

Mud is one of the main factor in drilling operations that has vital effect on drilling rate, type of drilling production and drilling optimization.The main aim of this project is to reviewing the type of mud and its effect on wells in Iranian oil field and other countriesAlso an introduction to the effect ofdrilling mud on production potential of wells. This paper contains different type of muds that are used for drilling operation to reduce drilling problems.Nowadays, the main problem is incorrect a well completion pplication of drilling mud in deep wells