Nile petroleum corporation

1. Engineer/ Dictor Omien

2. Oil Well cementing is the process of mixing
a slurry of cement and water and displacing
it down the casing, tubing or drill pipe to a
pre specified point in the well
Two types of cementing process
 Primary cementing
 Secondary cementing
CEMENTATION

4. PRIMARY CEMENTATION
The cementing takes place soon after the
lowering of casing is called primary cementation.
It is the process of mixing a slurry of cement
and water and pumping it down through steel
casing of the critical points in the annulus
between casing and open hole.

5. MAIN FUNCTIONS
• To bond and support the casing
• Protect the casing from corrosion.
• To restrict fluid movement between formations
• Protecting the casing from shock loads
• Sealing-off problematic zones.

6. High Press Gas
Fresh Water
Gas
Oil
Water
Oil
Surface Casing
Intermediate Casing
Production Casing
Conductor Casing
PRIMARY CEMENTING

8. Three most commonly used techniques :-
1. Single stage cementation
2. Multi stage cementation
3. Liner cementation
TECHNIQUES

9. SINGLE STAGE CEMENTING
It is the Most common technique
Normally accomplished by pumping
one batch of cement down the
casing between two rubber plugs.
The bottom plug is placed in the
casing, followed by cement slurry.
When the batch of cement has
been pumped into the casing, a top
plug is released.
The top plug is pumped down until
it lands on the top of float collar,
thus completing the cement job.

10. Float Shoe
Float collar
Bottom Plug
Top Plug
Centralizers
Cement Slurry
Well Fluid (Mud)
Pre-flush/ Spacer

11. FLOAT COLLARGUIDE SHOE

12. CEMENTING PLUGS

13. CENTRALIZERS

14. MULTI STAGE CEMENTATION

15. STAGE COLLAR FOR
MULTI STAGE CEMENTATION

16. 13-3/8” C/Shoe
(1200 M)
LINER
CEMENTATION
9-5/8” C/Shoe
(2800 M)
7” Liner Shoe
(3800 M)

17. POST JOB CONSIDERATION
WAITING ON CEMENT (WOC)
Compressive strength
500psi Resuming drilling
2000psi Perforation

18. CEMENT AND ADDITIVES
Cement
• Class ‘G’ Oil Well Cement
Chemicals & Additives
Used to change the properties of cement slurries.
• Accelerators
• Retarders
• Fluid Loss Additives
• Friction Reducer
• Defoamer

20. ANY CEMENTING OPERATION THAT OCCUR
AFTER THE PRIMARY CEMENTING OPERATION.
TYPES OF SECONDARY CEMENTATION
 PLUG CEMENTING
 SQUEEZE CEMENTING
SECONDARY CEMENTATION

22. PLUG CEMENTING
In plug cementing, a cement plug of a
specified length is placed across a
selected interval in an open or a cased
hole.
The cement is normally pumped through
open-ended drill pipe or tubing.

23. TECHNIQUE
BALANCE PLUG METHOD

24. Reasons for setting a cement plug
1. To stop lost circulation during drilling.
2. Directional drilling and side tracking.
3. To plug back a depleted zone.
4. Abandonment.
5. To provide anchor for open hole test tool.

30. SQUEEZE CEMENTING
The most common remedial method
used today is squeeze cementing.
In squeeze cementing -
The slurry is forced by pressure to a
specified point in the annulus to cause
a seal at the point of squeeze.

31. CLASSIFICATION BY PRESSURE
1. LOW PRESSURE SQUEEZING.
2. HIGH PRESSURE SQUEEZING.
SQUEEZING TECHNIQUES
1. BRADENHEAD.
2. PACKER SQUEEZE.

32. SQUEEZE TECHNIQUES

33. SQUEEZE TECHNIQUES

34. CLASIFICATION BY PRESSURE
LOW PRESSURE SQUEEZING
 Injection pressure < formation
fracture pressure
 Cavities and interconnected voids
filled with dehydrated cement
 Volume of cement small
 Perforation and channel clear of
mud and other solids
 Small node of cement filter cake
with properly designed slurries
 Highest success rate

35. CLASIFICATION BY PRESSURE
HIGH PRESSURE SQUEEZE
 Injection pressure > formation
fracture pressure
 Channels not directly connected to
perforations
 Impossible to remove plugging
material inside perforations
 Placement accomplished by
breaking down formation
 Location & orientation of fracture
not controlled.

36. SQUEEZE DEFINITION

37. Applications :
1. Supplement a faulty primary cement job.
2. Reduce water/oil, water/gas, or gas/oil ratio.
3. Repair casing leaks.
4. Stop lost circulation in open hole while drilling.
5. Supplement primary cement around a liner by
squeezing the top of the liner (during primary
cementation)
6. Sealing leakage of the liner top (in case of failure
after primary cementation).
7. Abandonment of single zones.

43. RE-CEMENT SQUEEZE

44. CHANNEL SQUEEZING

45. CASING SPLIT

46. LINER SQUEEZE

47. CEMENTING: PLANNING & JOB EXECUTION
•SLURRY DESIGN
•BLENDING & LOADING OF CEMENT
•WELL PREPARATION
Space for placement
Clean water
Mud pumps
Pressure gauges & stroke counter
Centralizer
Connection from stand pipe
Mobilization of equipment
JOB EXECUTION
POST JOB CONSIDERATION
• Casing pressure
• Waiting on cement