Break-out session presentation to discuss the influence of reservoir aspects on the selection of an artificial lift system. prepared for Praxis' Interactive Technology Workshop on Artificial Lift, Dubai, September 2013.

1. Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
Breakout Session
Andres Martingano
Artificial Lift 2013 – Praxis Interactive Technology Workshop

2. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Discussion of Screening Attributes and the Formation-Face
Operating Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

3. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Discussion of Screening Attributes and the Formation-Face
Operating Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

4. AL Selection Process
... Remembering previous presentation ...
• Three-step process, going from qualitative to quantitative
• The process is essentially the same at the stage of FDP or field operation,
except that during operations:
• Designs can be optimized, but
• There can be less flexibility to adopt a different AL method
Attribute tables
LOF Design
Economics
and
Scorecards
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
1. Screen
2. Evaluate
3. Select
• There can be less flexibility to adopt a different AL method

5. AL Selection Process: Some Guidelines
• Do not narrow down options too much at an early stage
• Define relevant attributes for screening based on project
needs
• Define the formation-face operating envelope before carrying
out any designs, so that proper constraints are consideredout any designs, so that proper constraints are considered
• Go beyond the total NPV to understand where value is being
gained or lost
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

6. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Discussion of Screening Attributes and the Formation-Face
Operating Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

7. Building a Better Attributes Table
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

8. Building a Better Attributes Table:
Focusing on Reservoir-Related Factors
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

9. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Discussion of Screening Attributes and the Formation-Face
Operating Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

10. Screening Attributes and the Formation-Face
Operating Envelope
• Two perspectives:
– Short-term view
– Long-term view
• Short-term view
– As far as the AL system is concerned, the formation-face and the– As far as the AL system is concerned, the formation-face and the
near-wellbore region of any specific well ARE the reservoir
– They determine rate, pressure, solids, temperature that the
system will handle
• Long-term view
– Reservoir performance over time becomes more important
– Life-of-field considerations become important
• How should you design?
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

11. Formation-Face Operating Envelope - Example
BHP
VLP to be achieved
P
Minimumrate
forstableoperation
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
Qliq
Pbp
Pformation integrity
Qmin Qmax
Pres initial
Pres abandon Minimum allowable BHP
Minimumrate
forstableoperation

12. Formation-Face Operating Envelope:
Factors Related to the Well
BHP
Presinitial
Minimumrate
forstableoperation
•Initial reservoir
pressure is largely
a function of depth
•PI is a function of wellbore
trajectory and radius
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
QliqQmin Qmax
Presinitial
Presfinal Minimum allowable BHP
• PI can also be a function of reservoir pressure, if there is
formation compaction, causing a reduction in permeability
• PI may increase over time if there is sand produced to the
surface
• If periodic stimulation is required
we may want to ensure that the
AL system will not be damaged,
and that the operation can be done
without having to pull the completion

13. Formation-Face Operating Envelope:
Factors Related to Reservoir Performance
BHP
Presinitial
Minimumrate
forstableoperation
•Reservoir pressure changes
over time will depend on
the reservoir drive and
any IOR / EOR scheme
•Changes in produced WC imply that
the effective permeability to oil has
been reduced, which will affect the PI
•Changes in produced GOR imply that
the effective permeability to liquids has
been reduced, which will be more
detrimental to liquid’s PI
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
QliqQmin Qmax
Presinitial
Presfinal Minimum allowable BHP
• Temperature is not a variable
in this plot, but if a thermal
recovery scheme is put in place,
it will make necessary for the AL
system to be able to operate at
those temperatures
•Reservoir behaving as dual porosity systems
can show a quick production and PI decline

14. Formation-Face Operating Envelope:
Factors Related to Flow Assurance
BHP
Presinitial
Minimumrate
forstableoperation
•For the same amount of CO2 or H2S,
at the same temperature,
greater pressures mean more corrosion
since their partial pressure becomes
greater
•If scale deposition is a risk, this
might be set based on the PT
equilibrium diagram to ensure the
salts remain in solution
P
T
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
QliqQmin Qmax
Presinitial
Presfinal Minimum allowable BHP
• If solids production were
a problem, the maximum
production rate could be limited
to prevent it
•If asphaltene deposition is a
risk, this should not fall bellow
bubble point pressure
T

15. Formation-Face Operating Envelope:
Factors Related to Fluid Properties
BHP
Presinitial
Minimumrate
forstableoperation
•Viscosity changes above the bubble point
are minor, but the effect below bubble point
is much more important, compounded by a
relative permeabilities effect
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
QliqQmin Qmax
Presinitial
Presfinal Minimum allowable BHP
•From an AL point of view, the
relation between the Pbp and the
intake pressure will determine the
GVF to be handled by the pump

16. Formation-Face Operating Envelope:
Factors Related to Reservoir Management
BHP
Presinitial
Minimumrate
forstableoperation
•The need to acquire downhole
data for reservoir surveillance
during the life of the well might
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
QliqQmin Qmax
Presinitial
Presfinal Minimum allowable BHP
•Maximum rates might be set to prevent
gas coning or water coning, or formation
damage due to fines migration
•For reservoir management
reasons, the bubble point pressure
might be chosen to be the
minimum acceptable static
reservoir pressure, and a guideline
to operate the wells around it
might be set
•Another reason could be to
prevent asphaltene deposition
during the life of the well might
me considered in the AL
selection process

17. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Discussion of Screening Attributes and the Formation-Face
Operating Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

18. Things to Consider About the Reservoir
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

19. Agenda
• The AL Selection Process
• Screening Attributes of Interest
• Screening Attributes and the Formation-Face Operating
Envelope
• Considerations About the Reservoir• Considerations About the Reservoir
• Exercise
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations
11 Sep 2013

20. Exercise: Participate in FDP Preparation
• Deliverables:
– Propose AL system(s) for the life of field
– Draw simple completion schematics for the wells
• Important:
– No right or wrong (in general) answers
– The process is important
– Step out of your AL role
– Collaborate with the team to improve plan
FDP
G&G
Reservoir
Engineering
Facilities
Engineering
Drilling
Production
Engineering
– Collaborate with the team to improve plan
• Steps:
– You will receive some information – some useful, some irrelevant, some misleading, some
lacking
– Screening (30 mins): Review with your teams what you think the issues will be, asking for
additional information if needed.
• Prioritize issues
• Decide options discarded and options to be considered further
• Choose a speaker and present to the rest of the teams
– Selection (30 mins): Review all you know now, keep seeking further inputs if required.
• Identify type of completion(s) to be used for the life of field: draw them
• Choose AL system(s) for the life of field: draw them
• Present your selection to the rest of the teams
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

21. Exercise: Comments
• Participants were given different scenarios to select AL
systems in support of a field development plan, based on
somewhat different conditions.
• A generic AL selection table was provided to the participants
as a reference for discussions.as a reference for discussions.
• Conditions were based on those found in fields across the
Golfo San Jorge basin, in Argentina.
• The exercise was prepared so that participants could compare
later their discussions with the experience of companies
operating in that region, as presented in paper SPE 108054.
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

22. Some Answers: SPE 108054
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations

23. Exercise: Highlights
• Participants found more than one option would work for the
given conditions (in general SRP and ESP), although specific
cases where highlighted as preferred for ESP or PCP.
• Participants suggested, in agreement with one of the
conclusions of the paper (unavailable to the them at the timeconclusions of the paper (unavailable to the them at the time
of the exercise), that a bigger casing size (7 in. instead of 5-1/2
in.) should be used to improve the capacity of the AL system.
– Interaction between disciplines is key to optimize de
development plan
– People from other disciplines might not be aware of your needs
or constraints, discuss them
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Artificial Lift Screening and Selection:
Focus on Reservoir Considerations