Tail production: Choosing the right strategy for Produced Water Management

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Tail productionChoosing the right strategy for
Produced Water Management

• K.I. Andersen

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Produced Water Daily Volumes

• Statfjord 160 000 m3/d
• Gullfaks 75 000 m3/d
• Snorre 25 000 m3/d
• Tordis/Vigdis 15 000 m3/d
• Veslefrikk 15 000 m3/d
• Heidrun 10 000 m3/d
• Norne 2 000 m3/d
• Åsgard 500 m3/d

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300 000 m3/d of produced water..
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Mars April 2004
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Oil rate development 2003 vs 1998 All GF
and SF wells
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Water rates pr. well 2003 vs 1998 All GF/SF
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Increased watercut scale, reinjection, water
shutoff, downhole separation
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Environmental impact (EIF) at Statfjord C
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Environmental impact (EIF) at Gullfaks A
Gullfaks A 2002


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Produced Water Management
Produced water treatment
Re-injection
Water shut off
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Authorities, Produced Water and Environment
Reduced Tolerance
vs.
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Produced Water Handling Principles
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1. Reduce chemical consumptionor change to
non-toxic

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H2S-removal by use of scavenger

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Environmentally friendly H2S removal

• ProPure C100 installed at Åsgard B May 2001
• Low capital cost
• Performance test in 2002
• 30 reduction in chemical consumption
  
• Low pressure drop (0.2 bar)
• Installed at Huldra, Veslefrikk, and Gullfaks B
  in 2002
• Installation at Gullfaks A and C in 2003

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2.

• Shut off waterproduction at source

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Well completion type dictates water shutoff
complexity
Screen
Cased
Horizontal, screen
Horizontal, cased
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Main Well Categories in Statoil(total -700
wells)
Complexity, zonal isolation
Openhole horizontal
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Perforated, cemented, horiz.
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Openhole, deviated
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Perforated,cement deviated
60
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- Cumulative annual water shut off
25 000 m3/d
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Ongoing RD Revisiting chemical route to water
shutoff
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Chemical water shutoff/Emulsified gel technology
Strong gel e.g. H2Zero
DPR- Classic i.e. polymer
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Rate effects of changing PI and WC
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RD continued Downhole separation - light
version

Objective Research of slip gravity separator
concept for downhole separation. By controlling
the stratified layers between oil and water in an
inclined tube, the layers can be controlled to
segregate through specially designed slots in the
tubing wall. Demo 2000 project - ABB, Statoil,
Shell Technology and NTNU.  
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Future Subsea Separation and PWRI
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3. Reinject water (PWRI)

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A-43 PWRI performance
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Statfjord field map
pilot well
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- Today reinjecting 30 000 m3 of water
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RD - PWRI Fracture growth improving our
modelling capability
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3. Dispose into aquifer

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Utsira a shallow saltwater reservoir
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Extent of Utsira aquifer
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- Kvitebjørn to dispose all produced water into
Utsira
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4. Purify and discharge

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Distribution of organic components in produced
water
WAF Water accommodated fraction
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The CTour process
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Results from CTour test at Statfjord B
These component groups are together with our
corrosion inhibitor the largest contributors to
EIF Blue line system performance (with
hydrocyclones), red line effect of condensate and
mixers only
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Questions?