Stuck Pipe Cause, Solutions & Prevention

1. What is the definition of Stuck Pipe?

a. Pipe that cannot be moved, circulation is sometimes possible.

b. Pipe that is stuck in the hole and cannot be pull out.

c. Pipe that has limited movement but circulation is possible.

d. Pipe that can be slowly pulled out of the hole but with excessive overpull.

2. What are the three mechanical forces (Mechanisms) that are responsible for stuck pipe?

a. Pack-off/Hole Bridge Wellbore Geometry Differential Sticking

b. High Mud Weights Excessive up-drag Key Seating

c. Loss of Circulation Hole Instability Hole collapse

d. Excessive Overpull Excessive Torque High Set-down Weight

3. While back-reaming out of the hole, overpull and torque increase and become erratic. Pump pressure is fluctuating by 300 psi. The TD stalls, circulation is lost and the pipe becomes stuck. What is the sticking Mechanism?

a. Excessive tight hole.

b. Poor hole cleaning and hole instability.

c. Hole Pack-off.

d. Hole Bridge.

4. While running the 9-5/8” casing, down-drag is increasing and high set-down weights (tight spots) or occurring every 1 to 2 joints. While washing down 5 joints later, the casing becomes stuck. Circulating pressure is normal but the casing will not move up or down. What is the sticking Mechanism?

a. Hole Bridge.

b. Hole Instability.

c. Excessive Centralizers.

d. Wellbore Geometry.

5. After pulling stand# 15, the slip dies were worn and had to be replaced. Ten minutes later, the drillstring was found stuck. The string cannot be moved up or down and rotation

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Stuck Pipe Cause, Solutions & Prevention

is impossible. The Top Drive is made up and circulation is normal. What is the sticking Mechanism?

a. The hole is partially packed-off.

b. Differential Sticking.

c. Key Seat Sticking.

d. Depleted formation pressure.

6. What is the most likely Cause of stuck pipe when drilling hole angles greater than 40º?

a. Inadequate hole cleaning.

b. Key seat sticking.

c. Hole collapse.

d. Micro Doglegs

7. While drilling, the circulating mud volume and bit cuttings should be the only material coming over the shakers. What hole problem is occurring if a large volume of splintered cavings if is observed at the shakers?

a. Inadequate hole cleaning.

b. The cement at the casing shoe is breaking apart.

c. High-pressure shale formation is caving into the wellbore.

d. An unconsolidated formation is caving into the wellbore.

8. What three factors control hole cleaning efficiency?

a. Hole size Mud density Rate of penetration

b. Hole depth Mud density Circulating volume

c. Mud density Mud viscosity Yield Point

d. Mud density Mud rheology Circulating volume

9. Why is 50º to 60º the most difficult hole angle to clean and the most likely to result in hole pack-off?

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Stuck Pipe Cause, Solutions & Prevention

a. Drillstring is on the low side of the hole Cuttings bed settle on the drillstring

b. High cuttings settling rate Cuttings bed avalanching

c. Cuttings settle to the low side Circulating flow moves to the high side

d. Increased hole instability Large volume of cavings

10. Of the three factors that control hole cleaning efficiency, which factor has the greatest effect?

a. Mud density.

b. Mud rheology.

c. Cuttings agitation with drillstring rotation.

d. Circulating rate.

11. In the majority of stuck pipe events (+/-70%), the first attempts to jar the pipe free should be in which direction?

a. Up.

b. Up and Down.

c. Down.

d. Up with maximum pipe torque.

12. When backreaming through a cuttings bed, why should the circulating rate be at least equal to the drilling circulating rate?

a. To help pump the drillstring out of the hole.

b. The large volume of cuttings will increase the density of the retuning mud.

c. Limited rig power will not allow maximum circulation rates while backreaming.

d. Cleaning a large volume of cuttings with a reduced annular velocity while pulling the drillstring.

13. Water base mud is bringing soft mushy cutting over the shaker: What down hole problem does this indicate?

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Stuck Pipe Cause, Solutions & Prevention

a. A soft shale formation is being drilled.

b. A water-sensitive shale is adsorbing water from the mud.

c. Excessive circulating rate is washing out a shale formation.

d. A mobile shale formation is squeezing into the wellbore.

14. Drilling hard/soft formation layers. Up-weight and off-bottom torque very erratic when back reaming the last connection. Just as the bit is pulled off bottom on the next connection, the top drive stalls and the pipe becomes stuck. No change in circulating pressure. What is the sticking Mechanism?

a. Wellbore Geometry.

b. Differential Sticking.

c. Hole Pack-off.

d. Hole Bridging.

15. In the sticking event of question 14, what is the Cause of the sticking Mechanism?

a. Unconsolidated Formations.

b. Cement Blocks.

c. Micro Doglegs.

d. Ledges.

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