Snorre B: Use of Measurements

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Snorre B Use of Measurements

• Raghu Kulkarni
• Statoil

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Statfjord
Gullfaks
Visund
Snorre reservoir 2,5 km below sealevel
BCU
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Outline

• Snorre B background information
• How we use the data/measurements on Snorre B
• Examples of benefit

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Snorre B
SNB
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Snorre B Status

• 7 producers, 4 smart and 3 conventional
  completions
• 5 injectors, all 5 are smart completions
• Real time data per sleeve PT on annulus and
  tubing side, sleeve opening

• 34 sleeves with 5 sensors per sleeve
• 12 wells, but monitoring challenge equal to that
  of 37 wells

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Outcrop, Escanilla Fm. Spain
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Snorre B Reservoir Management Challenges

• Several reservoir zones
• varying reservoir quality
• WAG injection
• Production/sweep Optimization
• Early gas, water breakthrough in some layers

Based on SNB experience so far, all future wells
on SNB will have DIACS as primary completion.
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Well D-6H
Isolation packers
SN 5
SN 4
SN 3
SN 2
Wellpath
OWC
SN 2
SN 3
SN 4
SN 1
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Slide 1/9
Snorre Production Monitoring DP Technique on D-6
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DT Monitoring

• DT monitoring provides indications of free gas
  breakthrough
• gas leads to lower specific heat
• higher turbulance
• more temperature loss
• lower pressure loss

• DT response on sleeve level not easy to interpret

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Gas Breakthrough D-4
Free gas breakthrough in sleeve 2.
DT monitoring indicative of changes in reservoir,
and sensitive to gas.
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Zonal Rates Estimation

• Can we estimate individual zone rates given dp
  values and total liquid or gas rate in single
  phase producers and injectors
• External program which modifies rates from each
  sink/source term until all pressures and rate
  data from tests matched

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Zonal Rates Estimation
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Snorre DIACS Producer Wells Follow-Up

• Production/Injection at well level allocated to
  sleeve level based on zonal rates estimation
  technique
• Sleeve level production allocated to reservoir
  level based on Kh product

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Snorre DIACS Injectors follow-up
Imagine the case if only total wellrate was known
..Ignorance is bliss!!
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Voidage

• Voidage is the balance on reservoir volume
  (injection, production in Rm3)
• On SNB voidage can be done on reservoir level

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Analysis to Action

• Extra 600 Sm3/d in D-4 for 103 days
• Extra 1000 Sm3/d in C-5 and 800 Sm3/d in C-6 for
  119 days

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Summary

• The downhole measurements are key to the advanced
  reservoir management on Snorre B
• DIACS together with the measurements allow
• Zonal rate estimation
• Voidage follow-up at reservoir level
• Voidage follow-up at reservoir level is the basis
  for DIACS sleeve operations and improved recovary
  on Snorre B