ANALYSIS OF MUD HYDRAULICS INTERACTIONS.

Importance of approaching the optimization of drilling variables in a logical sequence cannot be overemphasized. First and probably most important variable is the drilling fluid. Next, comes hydraulics, and finally, bit selection. Once the above three conditions are met, then optimum weight and rpm can be provided for the particular bit selected, and the proper interaction of the mud and hydraulics can be obtained. Effect of mud on the penetration rate is examined. Hydraulics should consider the type of mud to be used for providing adequate cleaning of the hole and maintaining hole stability. Finally, paper examines combined effects of mud and hydraulics and the ways for their optimization. Typical sample of MUDHY computer program's input and predictions is shown.