3. Mechanical Pipe Sticking
Mechanical pipe sticking are caused by
inadequate removal of drilled cuttings from
the annulus; borehole instabilities and key
seating.
4. Causes of Mechanical Pipe Stuck
• Drilled Cuttings
• Borehole Instability
- Reactive Shales
- Pressured Shales
- Fractured or Faulted Formations
- Unconsolidated Formations
- Cement or Junk in the Hole
• Key Seating
5. Drilled Cuttings
If cuttings are not removed from the borehole, they accumulate in the well,
eventually causing the hole to pack off, often around the Bottom-Hole Assembly
(BHA) and sticking the drillstring.
6. How to Prevent from stuck ?
• Using aggressive drill string rotation for
improved hole cleaning.
• Making a wiper trip after all long motor
runs.
• Using drillstring motion (rotate and
reciprocate), while circulating at the
maximum rate to disturb cuttings beds and
reincorporate them into the flow stream.
7. Borehole Instability
Depending on mud composition and mud weight, shale can slough in or plastically flow
inward, which causes mechanical pipe sticking.
Reactive shales
Pressured shales
Fractured and faulted formations
Unconsolidated formations
Cement or Junk in the hole
9. How to prevent from stuck?
• Limit the casing rathole to minimize the source of cement
blocks.
• Allow sufficient cement setting time before drilling out.
• Control drilling when cleaning out soft cement.
• Keep the hole covered when the drillstring is out of the
hole.
• Maintain rig floor equipment in good operating condition.
10. Key Seating
Key seating is a major cause of mechanical
pipe sticking. The mechanics of key seating
involve wearing a small hole (groove) into
the side of a full-gauge hole.
11. Cause of Key Seating
• This groove is caused by the drillstring
rotation with side force acting on it.
• Long bit runs
12. How to prevent from stuck ?
If the pipe is stuck in a key-seat area, the
most likely successful solution is backing off
below the key seat and going back into the
hole with an opener to drill out the key
section. This will lead to a fishing operation
to retrieve the fish.
13. DIFFERENTIAL PRESSURE PIPE STUCK
Differential pressure pipe sticking happens when a portion
of the drill string becomes embedded into a mud cake
which create a permeable zone during the drilling (Azar,
JJ., Drilling Engineering, p. 356. )
14. Causes of Differential Pressure
Pipe Stuck
• Thick mud cake
• Excessive pipe length in mud cake
• High differential pressure
• Low –Lubricity mud cake
15. Thick Mud Cake
If the selected mud is non-smooth and thick because of unpredictable
reasons ,then the area between pipe surface in contact with the filter
cake will increase. This will result in a higher force.
16. Excessive Pipe Length in Mudcake
Unnecesarily excessive pipe length in mud cake is
a cause of pipe sticking .This may be resulted by
narrowing the area and finally a higher force
exerted on the mud cake surface.
17. High Differential Pressure
The exerted pressure by the mud column is
getting higher than the formation pressure in
this case. The indication of this differential
can be clearly seen on the torque indication.
The indicator show an up and a down
movement when the pipes are tried to pull
up.
18. Low Lubricity Mud Cake
The poor in quality muds the high tendency
to pipe stuck.
19. How to Prevent from stuck ?
• Lowest fluid loss
• Lowest drilled solid’s level
• Smooth mud cake
• Maintaining the rotation
20. Methods to Overcome Sticking
• Mechanical method
-Release of pipe
• Chemical method
-Lower fluid density
-Surfactant and lubricant addition
-Spotting a freshwater pill
• Hydrostatic method
-Nitrogen injection
21. • Izzettin PALA
• Levent Onay
• Ahmet BAKIR
• Mustafa Ali KIZTANIR
PIPE STICKING PRESENTED BY
