workover job ppe
TRANSCRIPT
TO: ENGR SIR HABIB U ZAMAN MEMON
FROM: MUHAMMAD HANIF CHACHAR
(12PG142)
TOPIC: WORKOVER JOBS
MEHRAN UET JAMSHOROSINDHPAKISTAN
What is “workover” job?
Why it is necessary?
Reasons
The term workover is used to refer any
kind of intervention.
It refer to the very expensive process of
pulling and replacing a completion.
Workover operations are carried out for
mainly two reasons such as:
1) Mechanical problems
2) Reservoir Related Problems
a) Repair/Replace of damaged equipment
b) Capital repairs of well
c) Replace artificial lift equipments
d) Fishing
Downhole environments damage
equipments during the life of a well.
(Like Erosion, Chemical reactions,
Temperature extremes etc…)
Production tubing
Tubing packers
Subsurface safety valves etc…
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.
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
Retrieval of equipments from wellbore, (Expensive, Stucked & Reused) Such as:-
Drill pipes
Drill collars
Logging tools
Packers
Tubing etc…
a) Repair natural damage within the well
b) Zone Transfer
c) Stimulation
d) Convert well from production to injection
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…
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.
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…
At certain time well production will be uneconomical
CO2 or water can be injected
Waste fluids or drilled cuttings can also be
injected
Advisor Sajjad Ali Jogi(146)