Drill String- Drill Collar, Kelly and Stabilizer

Drill String- Drill Collar, Kelly and Stabilize

1.Drill Pipe: 

We introduced drill pipe in our last blog, we introduce the drill string-Drill Collar, Kelly and Stabilizer in this blog。

2. Drill collar

Structural features: Threads are directly machined at both ends of the pipe body, without special joints; large wall thickness (38-53 mm), heavy weight, and high stiffness.

main effect:

(1) Apply drilling weight to the drill bit;Kelly

(2) Ensure the necessary strength under compressive stress conditions;

(3) Reduce the vibration, swing and beating of the drill bit to make the drill bit work smoothly;

(4) Control well deviation.

Type: smooth drill collar, spiral drill collar, flat drill collar.Drill Collar

Common sizes: 6-1/4″, 7″, 8″, 9″.

3. Kelly 

Type: square, hexagonal

Features: Larger wall thickness and higher strength

Main function: transmit torque and bear the entire weight of the drill string.

Common sizes: 89mm (3.5 inches), 108mm (4.5 inches), 133.4mm (5.5 inches).

4. Stabilizer

Type: Rigid stabilizer, non-rotating rubber sleeve stabilizer, roller stabilizer.Stabilizer

effect:

  1) Anti-tilt;

  2) Control the wellbore trajectory.