## Workshop

### SCORE

1. Convert the following mud densities into pressure gradients.
2. 13.5 ppg b. 16 ppg c. 12 ppg psi/ft psi/ft psi/ft
3. Convert the following gradients into mud densities.
4. 0.806 psi/ft b. 0.598 psi/ft c. 0.494 psi/ft ppg ppg ppg
5. Calculate the hydrostatic pressure for the following.
6. 9.5 ppg mud at 9000ft MD/8000 ft TVD =_
7. 15.5 ppg mud at 18000ft TVD/21000ft MD =_
8. 0.889 psi/ft mud at 11000ft MD/9000ft TVD =_
9. Convert the following pressures into equivalent mud weights in PPG.
10. 3495 psi at 7000ft b. at 4000ft with 2787 psi c. 12000ft MD/10500ft TVD with 9000 psi

High bottom hole temperatures could affect the hydrostatic pressure gradients resulting in:

a. An increase in the hydrostatic gradient b. A decrease in the hydrostatic gradient c. Would have no effect 2

SECTION 1 : FUNDAMENTAL PRINCIPLES OF WELL CONTROL

### SCORE

6. Assuming a 10 ppg mud is being circulated at 700 GPM at a depth of 10000ft TVD/MD the circulating pump pressure is 3000 psi. If the circulating friction losses in the system are as follows:

Pressure losses through pipe/collars 1200 psi

Pressure loss across the bit jets 1600 psi

Pressure loss in the annulus 200 psi a. When circulating what is the dynamic bottom hole pressure?

b. What is the static bottom hole pressure?

c. What is the equivalent circulating density ECD?

d. If the pump speed is increased to give 800 GPM, what will the pump pressure be?

e. Will this increase in the pump speed have any effect on bottom hole pressure?

f. Referring to the data given above, if the mud weight being circulated at 700 GPM was 12 ppg rather than 10 ppg, what would pump pressure be?

7. When circulating a 12 ppg mud at 10000ft ECD is 12.3 ppg. What is the annular pressure loss?

SECTION 1 : FUNDAMENTAL PRINCIPLES OF WELL CONTROL

### SCORE

1. Calculate the pressure that one barrel of 12 ppg mud Wt exerts.
2. Around the drill collars if the annular capacity is 0.03 bbls/ft.

b. Around the drill pipe if the annular capacity is 0.05 bbls/ft.

9. If the fluid level in a well bore fell by 480ft, what is the reduction in bottom hole pressure if the mud weight is 12 ppg?

10. If a 12 ppg mud over-balances the formation pressure by 240 psi theoretically how far could the mud level fall before going under-balance?

11. Drilling at 12700ft with an 8 1/2" bit, the drill pipe is 5" with 700ft of 6 1/2" collars. The mud weight = 12 ppg. The yield point of the mud is 12lbs/100ft2. Use the equation given below to determine ECD.

Annular-pressure loss = YP x L

200(DH-DP)

where YP = Yield point of mud in lbs/100ft L = Length of annulus, collar or pipe DH = Hole diameter DP = Collar or pipe diameter

12. If a formation pore pressure gradient at 8500ft is 0.486 psi/ft, what mud weight is required to give an over-balance of 200 psi?

SECTION 1 : FUNDAMENTAL PRINCIPLES OF WELL CONTROL 