This document provides training on well control, barriers, and killing an intervention well. It discusses the three factors that govern well control: personnel, equipment, and plans/procedures. It defines barrier types and requirements for drilling and intervention wells. Methods for killing a well include bullheading, forward circulation, reverse circulation, and lubricate and bleed. Proper preparation, information, and pumping equipment are needed to kill a well safely while preventing formation damage. Common challenges include surge pressures, swab pressures, and blockages.

1. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
FST
TRAINING
Human factory
WELCOME TO

2. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Well CONTROL
2.6

3. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
3 factors govern the Success of Well Control:
1. Personnel
2. Equipment
3. Plans & Procedures
1. PERSONNEL
• ASK
• Communications
• Responsibility
2. EQUIPMENT
• Full Inventory with Spares
• MPT Full Specification
• Function & Pressure Tests
3. PLANS & PROCEDURES
• Well Plan & Consider All Aspects
• Back-up Plans & Procedures
• Procedures Tailored to Site
PHILOSOPHY

4. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
IWCF BARRIER DEFINITION:
Barrier is any device, fluid or substance that prevents
flow of wellbore fluids.
IWCF BARRIER CLASSIFICATION:
1. Primary Barrier
2. Secondary Barrier
3. Tertiary Barrier
IWCF BARRIER REQUIREMENT :
1. Drilling & Workover – Double Barriers Protection
2. Well Intervention – Triple Barriers Protection
1st line of defense system, Close type barrier.
2nd line of defense system, Closable type barrier.
Last line of defense system, Closable type barrier
with ability to shear tubing/wire & seal pressure.

5. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
1. Mechanical Barrier
1.1 Closed Type
1.2 Closeable Type
2. Hydrostatic Barrier
Must be “Tested From Direction of Flow”
Must be “Leak Tight”
API leakage criteria “400 cc/min or
900 scf/hr”
Must be diligently monitored for a
period of time to Ensure Thermal
Expansion & Contraction Effects
Have Ceased.
Hydrostatic Barrier Criteria:
• Liquids with circa 200 psi ▲ Pf
or ▼ Pff
• Must be observable from
surface.
BARRIER TYPE & BARRIER INTEGRITY

6. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
1. Mechanical Barrier
2. Hydrostatic Barrier
Advantage:
• Eliminate formation damage
• Cost effective
Disadvantage:
• Working under pressure.
WL PLUG
PACKER
DHSV
XMAS TREE
BOP
STUFFING BOX
FORMATION FLUID
MUD
Advantage:
• Working in dead well.
Disadvantage:
• High potential of formation damage.
LUBRICATOR
CASING
TUBING
Dead Well
Well Pressure
FORMATION FLUID

7. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
BARRIER EXAMPLE
MECHANICAL BARRIER
CLOSED TYPE CLOSABLE TYPE
Stuffing Box BOP
Grease Injection Head Annular Preventer
Stripper Xmas Tree
BHA Check Valve Subsurface Safety Valve
HYDROSTATIC BARRIER
Drilling Fluids Fresh Water
Completion Fluid Salt Water
OTHER BARRIER EXAMPLES
WL Plugs Ice Plugs
Bridge Plugs Overbalanced Fluid

8. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
BARRIER ENVELOPES
Barrier envelope is a group of individual barrier elements.
Examples:
Stuffing Box is part of Lubricator Envelope.
Xmas Tree is part of Packer Tubing Envelope.
Casing is part of Production Casing Envelope etc

9. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
STUFFING BOX/LUBRICATOR ENVELOPE
Barrier elements include:
• BOP
• Lubricators
• Stuffing Box

10. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
PACKER/TUBING ENVELOPE
Barrier elements include:
• Packer
• Tubing
• Tubing Accessories
• Tubing Hanger
• Xmas Tree

11. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
PRODUCTION CASING ENVELOPE
Barrier elements include:
• Production Casing
• Side Outlets Valves
• Tubing Hanger
• Tubing Head
• Casing Head Housing

12. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
PACKER/TUBING/DHSV ENVELOPE
Barrier elements include:
• Packer
• Tubing
• Tubing Accessories
• DHSV

13. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
DRILLING
(Double Barrier Protection)
WELL INTERVENTION
(Triple Barrier Protection)
BOP
Mud
Formation Fluids
SECONDARY BARRIER
PRIMARY BARRIER
PRIMARY BARRIER
SECONDARY BARRIER
TERTIARY BARRIER
Stripper
Annular BOP
Annular BOP
BOP
Shear & Seal BOP
Formation Fluids

14. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Other Definition
• Overbalance
• Underbalance
• Inflow Test
• Positive Plug
• Barrier
Hold pressure from ▼ & ▲
Bleed pressure from ▲ & monitor build-up
Less pressure than formation pressure
Greater pressure than formation pressure
Device, Fluid or Substance that prevent flow of hydrocarbon

15. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
FORMATION DAMAGE &
WELL KILLING

16. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Well Intervention most notably formation damages are;
• Pore or perforations plugging by kill fluid solids, scale or debris.
• Permeability reduction by kill fluid filtrate invasion or insoluble
precipitates formed during acid stimulation with hydrofluoric acid.
• Sand face/cement breakdown due to acid stimulation effects.
• Clay swelling from incompatible brine or water contamination..
FORMATION DAMAGES

17. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
To prevent formation damage there is a minimum drawdown between
the bottomhole pressure where a well is able to flow or be injected:
∆P = P Bottom Hole – P Reservoir
P < 0 for a well to flow.
P > 0 for injection into reservoir.
 for a particular formation P should be determined to minimise flow
from or into the reservoir.
In general, during a well kill against the formation the bottomhole
pressure should be kept as follows:
∆P = < P Bottom Hole < P Injection
∆ PRESSURE

18. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
• Compatibility of the brine with the formation
• Weight required
• Preparation of the brine
• Cleanliness
• Health & safety aspects
• Pollution control measures
Clear brines are used to prevent formation damage providing the
following points are considered:
WORKING FLUIDS

19. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
BRINES COMPOSITION
Potassium Chloride KCl 8.3-9.7 lbs/gal
Sodium Chloride NaCl 8.3-10.0 lbs/gal
Calcium Chloride CaCl 8.3-11.8 lbs/gal
Calcium Chloride/
Calcium Bromide CaCl /CaBr2 11.8-15.2 lbs/gal
Calcium Chloride/
Calcium Bromide/
Zinc Bromide CaCl /CaBr2 /ZnBr2 14.5-19.2 lbs/gal
Zinc Bromide ZnBr2 13.5-21.0 lbs/gal

20. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Clean fluids is the most essential prevention of formation damages.
1 Fluids Isolation
• If possible always isolate fluids from formation by setting a
mechanical barrier.
2 Fluids Cleanliness
• Filtration unit or Centrifuge
3 Fluids Selection
• Compatible
• Crystallization or Freezing Free fluids
• Maintain pH
• Consider Inhibitors
DAMAGE PREVENTION

21. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
WELL KILLING
Well Intervention Well Kill Method:
1. Bullhead
2. Forward Circulation
3. Reverse Circulation
4. Lubricate & Bleed
The most preferable method in case of emergency.
Minimize formation damage.
Best planned kill method.
Last resort & under extreme case only.

22. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
BULLHEAD
Pump fluid thru tubing with 2 volume of sea
water & followed by kill fluids at high rate &
squeeze into formation at given overpressure
(< Pff)
Advantages:
• Quick & easy methods especially in smaller tubing
• No hydrocarbons brought to surface.
Disadvantage:
• Scales or contaminants in the tubing are pumped
into formations.
• Low formation pressures may be exceeded
causing accidental fractures.
• Gas may slip up the tubing if the pump rate is not
sufficient for larger tubing size.
IN
SSD
Perforations
Tubing
Casing
Packer

23. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Strokes
Tubing
Surface
Pressure
Tubing Volume
Tubing Head Pressure
plus Injectivity Pressure
BULLHEAD KILL CHART

24. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
FORWARD CIRCULATION
Pump fluid thru tubing & return thru casing.
Advantage:
• Little or no damage to formation by foreign fluids or
contaminants from tubing or annulus.
Disadvantages:
• Risky of flowing hydrocarbons through section “C”
annulus & disposal is difficult.
• Gas & oil will mix with packer fluid due to gravitation
& requires special handling equipment.
• High circulation pressure on the annulus.
OUT
IN
SSD
Perforations
Casing
Tubing
WL Plug
Packer
Oil
Casing

25. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
FORWARD CIRCULATION KILL CHART

26. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
REVERSE CIRCULATION
Pump fluid thru casing & return thru tubing.
Advantages:
• Hydrocarbons flow through Xmas Tree facilities.
• Gas & oil remain segregated through out.
• Low circulation pressure on the annulus.
• Little or no damage to formation by foreign fluids
or contaminants from tubing or annulus.
• Little risks of accidentally fracturing formations.
Disadvantage:
• Slower than Bullheading method
OUT
IN
SSD
Perforations
Tubing
Casing
Packer
WL Plug

27. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
REVERSE CIRCULATION KILL CHART

28. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
LUBRICATE & BLEED
Pump & bleed alternately fluid thru tubing until
well is dead.
Advantage:
• Only method which can be employed under
extremes circumstances.
Disadvantages:
• Very slow.
• Pressures equalization across tubing is difficult
to achieve.
• Requires higher surface pressure than
circulation methods.
ALTERNATE
CYCLING
IN & OUT
SSD
Perforations
SSD
Casing
Packer

29. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
Strokes
Tubing
Surface
Pressure
Minimum
Surface Pressure
to Prevent Influx
MASP
Tubing Volume
LUBRICATE & BLEED KILL CHART

30. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
PREPARATION FOR WELL KILL
1. Well must be closed in to stabilise bottomhole pressure.
2. Inspect & service Xmas tree.
3. Check whether SSSV needs to be locked open or pulled
(WRSV).
4. Isolate well from Production Control System & ESD if
necessary.
5. Ensure all Well Intervention Equipment has been organised
including pumping equipment.

31. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
INFORMATION REQUIRED
1. Fluid Levels In Tubing
2. Wellhead Pressure Rating
3. Formation Pressure
4. Formation Fracture Pressure
4. Casing & Tubing Sizes
5. Casing & Tubing Strengths
6. Injectivity Pressure
7. Maximum Allowable Surface Pressure (MASP)

32. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
PUMP EQUIPMENT
1. Pump
2. Surface Pump Lines
3. Choke Manifold
4. Isolation Valves
5. Pressure Gauges
6. Fluid Disposal System
7. Mixing Tanks
8. Reserve Tanks
9. Fluid
10. Chemicals
MIXING
TANK
STORAGE
TANK
PUMPING
UNIT
PUMP LINE
CIRCULATING LINE
RETURN LINE DISPOSAL LINE

33. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
OPERATIONAL CHALLENGES
Well Intervention Common Challenges are:
1. Surge Pressure
2. Swab Pressure
3. Blockages
1. Surge Pressure
Piston Power arises from RIH:
• Small clearance (between CT OD / tubing ID) produces ▲pressures.
• Completion fluids produces ▲pressure than oil/gas).
• ▲speed produces ▲pressures.
• Longer OD tools produces ▲pressures.
• May activate pressure-activated equipment downhole.
Prevention:
4 Deviation
5 Hydrates
Slow down while RIH especially at downhole accessories.

34. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
OPERATIONAL CHALLENGES - continuation
2. Swab Pressure
Piston Effect occurs when downhole equipment is being POOH:
• Small clearance (between CT OD / tubing ID) produces ▲pressures.
• Completion fluids produces ▲pressure than oil/gas).
• ▲speed produces ▲pressures.
• Longer OD tools produces ▲pressures.
• Greater effect when downhole tools closer to reservoir & causes
hydrocarbon to be drawn out from reservoir.
Prevention:
Slow down while POOH especially at downhole accessories.

35. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
OPERATIONAL CHALLENGES - continuation
3. Blockages
• Sand Bridge
• Scale
• Paraffin
• Wax
• Hydrates Plug
• Collapsed casing, liners, tubing or jammed valves etc.
Removing Blockages
• Mechanical methods
• Chemical methods

36. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
OPERATIONAL CHALLENGES - continuation
4. Deviation
• Friction
• Colloidal effect
• Unable to reach desired depth
Solution
• Retry cautiously
• Roller subs
• Tractors or Locomotive
• Alternate well interventions method

37. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
OPERATIONAL CHALLENGES - continuation
5. Hydrates
Crystalline water structures filled with small molecules. These conditions
form hydrates;
• Presence of free water
• Presence of light gas molecules
• Relatively high pressure
• Relatively low temperature
Removing Hydrates
• Reduce pressure
(Risk: hydrate plug slips & gas above it, the plug may blow up).
• Raise temperature
• Use inhibitor (glycol, methanol or salt).

38. FIELD SERVICE TECHNICIAN TRAINING - HUMAN FACTORY
THE END
&
THANK YOU