Stuck pipe in drilling petroleum basic

1. Stuck pipe

2. Introduction Stuck pipe
• Stuck pipe: An interruption
in planned operations as
excessive drag forces
prevent pulling the drill
string out of the hole.

3. Stuck pipe
Mechanisms
Hole Pack Off
(Bridge)
Differential
Well bore
geometry

4. Hole pack off/Bridge mechanism
Pack off: Small pieces of formation, cement or junk settle around the
drill string preventing circulation with no string movement likely.
Bridge: Medium to large
pieces of formation, cement
or junk settle around the
drill string allowing
restricted circulation with
little to no string
movement.

5. Hole Pack off/Bridge Causes
Inadequate hole cleaning
Cement related
Well bore instability
Special
Settled cuttings
Geo-pressurized shale
Hydro-charged shale
Reactive shale
Overburden/tectonic stresses
Unconsolidated /fractured
formations
Plastic formations
Cement failure / Soft cement
Junk in hole

6. Inadequate hole
cleaning
• The inability to efficiently remove formation solids
(cuttings , cavings) from the wellbore
Causes
-High ROP: Cutting fast generation
-Rock mechanical failure: More cutting generation
-Low AV: Low pump speed/Hole enlargement
-Low mud reology: YP/Gel
-Circulation not maintained long enough

7. Inadequate hole
cleaning
Prevention
-Limit ROP/hole cleaning efficiency
-Sufficient Mwt & Reology.
-Minimize low gravity solids.
-Pump Hi Vis Sweeps .
-Minimize connection time.
-Circulate hole clean before POOH.

8. Well bore
instability
Reactive shale
Causes
-Drilling a water
sensitive shale with a
non inhibited drilling
fluid.
Prevention
- If possible, use OBM.
-Use inhibitors to WBM to
prevent WTR adsorption
to shale.

9. Well bore
instability
Overburden stresses
Causes
-Insufficient Mwt. To
support
the overburden stress of
increasing hole angle
and/or depth.
Prevention
-Pre plan and maintain
Mwt. Increase schedule
relative to hole angle.

10. Soft cement
Causes
-A part of the drill string
is run into the top of
cement before
circulation.
Prevention
-Accurate calculation for
the top of CMT.
-Washing & reaming 2
stand before the top of
CMT.
Cement related causes

11. Junk in hole
Prevention
-Ensure the hole is protected
with a hole cover.
-Closing blind rams BOP when
the bit is pulled out of the hole.
Causes
-Any foreign material, lost tool
or object in the wellbore that
prevent
-Not covering the hole.
Special
causes

12. Differential sticking
The sticking force by the overbalance pressure driving the static
Drill string into the thick filter cake of a permeable formation
Five basic conditions
1- The string must be in
contact with the wall of the
hole
2- static for some time.
3-Overbalance pressure
drives fluid into the zone
4- permeable zone and
develops

13. Differential sticking
Differential sticking Prevention
Five basic rules
1-Minimize Overbalance Pressure
2-Minimize Formation Permeability
3-Minimize Filter Cake Thickness
4-Minimize string contact area
5-Continuous pipe movement

14. Well bore geometry
Hole angle or direction
change
Assy stiffness
Under gauge hole diameter
Key seating
Micro-doglegs
Ledges
Thick filter cake
Under gauge hole
Mobile formations
Stiff BHA
Stiff CSG Assy

15. Hole angle or direction change
Key seating
High drill string side
forces during the
drilling operation
wears a slot into side
of the hole giving the
hole the appearance of
a key seat.

16. Hole angle or direction change
Key seating
Causes
-Heavy string tension produces a high side force to the
wall of the hole at the dogleg depth.
-String movement (rotation, reciprocation) from a
long-term drilling interval(s) wears a slot into the
formation.

17. Hole angle or direction change
Key seating
Prevention
-Design the directional plan with minimum possible
dogleg severity.
-Plan frequent survey points through the turns to reduce
the severity of the angle/direction corrections.
-Maintain constant weight on bit while drilling hard /soft
fm interfaces and fault zones to avoid doglegs.
-Do not force the BHA through tight spots. Be prepared to
back ream if overpull limits are reached.

18. Stuck pipe- Freeing Equipment
Drilling Jar : drill string
component designed to
deliver up or down jar
impact loads to the pipe
that is stuck below it's
string position.

19. Drilling Jar Mechanical jar
operation

20. Drilling Jar Hydraulic jar
operation

21. HOLE CLEANING