workover job

1. TO: ENGR SIR HABIB U ZAMAN MEMON
FROM: MUHAMMAD HANIF CHACHAR
(12PG142)
TOPIC: WORKOVER JOBS

2.  What is “workover” job?
Why it is necessary?
Reasons

3. The term workover is used to refer any
kind of intervention.
 It refer to the very expensive process of
pulling and replacing a completion.

10. Workover operations are carried out for
mainly two reasons such as:
1) Mechanical problems
2) Reservoir Related Problems

11. a) Repair/Replace of damaged equipment
b) Capital repairs of well
c) Replace artificial lift equipments
d) Fishing

12. Downhole environments damage
equipments during the life of a well.
(Like Erosion, Chemical reactions,
Temperature extremes etc…)

13. Production tubing
Tubing packers
 Subsurface safety valves etc…

14. Most complicated and time consuming
operations.
They include:
• Drilling and milling of packers.
• Detection & repair of casing damages &
recompletion
• Fishing & removal of stuck like tubings,
packers & other downhole tools &
recompletions.

15. When reservoir become unable to produce
at an economical rate, Then artificial lift is
required.
There are four basic types of artificial lift:
i) Rod pump
ii) Hydraulic pump
iii) Electric submersible pump (ESP)
iv) Gas lift

16.  Retrieval of equipments from wellbore,
(Expensive, Stucked & Reused) Such as:-
 Drill pipes
 Drill collars
 Logging tools
 Packers
 Tubing etc…

17. a) Repair natural damage within the well
b) Zone Transfer
c) Stimulation
d) Convert well from production to injection

18.  Term “Natural Damage” refers to damage
in the reservoir rock or the fluids within it.
For Example:
 Near-Wellbore Formation Damage
 Sand Production
 Excessive Gas Production etc…

19. One of the most common reason for a
workover is to recomplete a well from one
zone to another.
 Many wells are drilled to intentionally
penetrate many zones,
 but only one zone at a time is produced.
 In some wells, lower zones are produced first.
 When reservoir depleted, they are
recompleted (isolated) so that another zone
farther up can be produced.

21.  Stimulation is general term describing variety of
operations performed on a well to improve its
productivity.
 It plays a vital role in production operations.
 Production in a damaged or low-producing zone
can be increased by some techniques as follow:
 (i) Acid Stimulation
 (ii) Hydraulic Fracturing
 (iii) Water Injection etc…

22.  At certain time well production will be uneconomical

23. CO2 or water can be injected
Waste fluids or drilled cuttings can also be
injected

26. Advisor Sajjad Ali Jogi(146)