Common causes and solutions for drill rods jamming

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Common reasons:
Unstable wellbore

The collapse of the formation, reduction in diameter, or block falling from the wellbore can cause the drill pipe to get stuck.

Preventive measures: Optimize drilling fluid performance (such as increasing viscosity and plugging), and control wellbore trajectory.

Rock debris accumulation (sand settling and stuck drilling)

Insufficient drilling fluid displacement or prolonged pump shutdown can cause rock debris to deposit and wrap around the drill pipe.

Preventive measures: Maintain the circulation displacement and rock carrying efficiency, and avoid long-term pump shutdown.

Keyway locking drill

Frequent rotation in the directional well forms a keyway, and the drill rod is stuck in the keyway.

Preventive measures: Regularly perform short trips to repair the wellbore and control dogleg deviation.

Adhesive stuck drill (differential pressure stuck drill)

The filtration loss of drilling fluid is large, forming thick mud cake, and the drill pipe and wellbore are adsorbed due to pressure difference.

Preventive measures: Reduce the filtration loss of drilling fluid and use lubricants or extreme pressure grease.

Operational error

Excessive drilling speed can cause pressure stimulation or unreasonable drilling parameters (torque, drilling pressure).

Emergency response plan:
Attempt to move drilling tools

Move the drilling tool up and down (avoiding strong pulling and twisting), while circulating the drilling fluid, gradually increasing the tension to the safe limit.

Adjust the performance of drilling fluid

Inject high lubricity drilling fluid or unblocking agent (such as diesel+surfactant).

Shock release card

Apply high-frequency vibration using a drilling vibrator or ground vibrator.

Soaking acid or unblocking solution

For mud cake adsorption sticking, inject acidic liquid or specialized unblocking agent for soaking.

Inverted or nested milling

If the jam cannot be resolved, the upper drilling tool needs to be inverted and removed, and then the milling cylinder should be inserted to remove the jam.