The document discusses workover jobs, which refer to interventions done on oil and gas wells to repair downhole equipment and address reservoir issues affecting production. Workovers are necessary when mechanical failures occur or reservoir conditions change. Common reasons for workovers include replacing damaged equipment, fixing casing issues, removing stuck tools, and addressing natural reservoir damage or depletion that reduces productivity. Workovers can involve complex operations like milling packers, fishing operations, and zone recompletions to restore or boost well production.

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

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)