The drilling fluid program is designed and selected according to many factors and criteria for successful drilling operations. The better the drilling fluid is designed and selected, the more efficient and effective drilling operations are possible. Answer the following Questions. i. Discuss the factors affecting the drilling fluid selection for highest ROP. ii. Describe the role of fluid viscosity for the successful drilling operations and also expla the potential problems during drilling operations if there are changes in fluid viscosity. iii. Describe the relationship between mud density and overall drilling performance. iv. Identify the parameters affected by the changes in resistance of the fluid to flo, which may affect the drilling performance. (425=100marks)