5. Say we have a well with 8000 ft of 4.26 x 5 drillpipe and 500 ft of 8 x 3 collars. The viscosity is 15 cp with 10 ppg mud. The hole is 10 inches in diameter. The vg meter reads 15 cp at 300 rpm and 20 at 600 rpm. The bit has 3 nozzles at 12/32's (make sure you can do this by hand.. you can check it with the spreadsheet) a. At static conditions what is the pressure at the bottom of the well? b. What is the pressure at the bottom of the well while circulating? (Bingham plastic model) c. What is the hp at the bit d. What is the pump pressure?

Fig: 1