Gullfaks%20S

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Gullfaks Sør, N1/N0 og Gullfaksfeltet
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Gullfaks Satelitter Prosjektforslag til Gullfaks
Landsbyen 2006 Bruk av multilaterale brønnerpå
GFS Statfjord,
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Gullfaks Sør Statfjord Formation
Discovered in 1979, and part of the Gullfaks
Satellites tie in to Gullfaks field 10
km Statfjord formation consist of 134 m oil zone,
and gas cap Statfjord formation Production
start April 1999 Reservoir depth 3300
m Pressure, initial 476 bar Temp. _at_ 3300 m 128
oC
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GFS Statfjord

• Challenge
• Complex reservoir with low recovery, goal 18
  (LTP 2003-2008)
• PDO 12.6 MSm3. Today 5.4 MSm3
• Increasing GOR -gt reduces the oil rates.
• Aggressive search to increase recovery factor
• EXTENDING THE LIMITS - STEP BY STEPS
• Additional perforation of G-2 H and F-4 H in
  lower Statfjord (summer 2003)
• G 1 H with RMC (2003/2004)
• G 2 YH MLT with RMC (2004)
• F 2 YH MLT with RMC (2004)

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Development of GFS Statfjord reserves
F-4 / G-2 drilled
DIACS / MLT
G-3 drilled
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Why MLT and Remote Monitoring Control?

• Poor reservoir communication and structural
  complexity ? More drainage points reduces the
  uncertainty.
• The need for more drainage point is clearly based
  on the STOOIP and estimated volume pr. well.
• A smart well and MLT well will be more robust
  for the geologic complexity and uncertainty in
  the reservoir.
• More drainage points
• will increase the estimated production pr well
• expose more of the reservoir
• minimize the drawdown
• extra reservoir penetrations also allows access
  to reserves that otherwise would be likely to be
  left behind.

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Why MLT and Remote Monitoring Control?

• Production experience.
• Want to keep old wellbore
• Verify contribution from each branch
• Optimize, if possible, the contribution from each
  branch, different drawdown and GOR
• Adjust production from different zones by surface
  operated valves.
• Clean-up of well easier with RMC
• More flexibility when co-producing with the other
  wells
• Natural gas lift
• Limited number of slots
• Aquire more data about pressure communication in
  the reservoir.
• Smart well technology is an insurance and it
  provides more data.
• Reduces the need for expensive well interventions

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Production profile one vs. multiple branches

• Eclipse simulations used for justification of
  MLT
• Decision tree, evaluating well concept used.
• Increased production and accelerated effect.
• Possible to produce from areas of low
  productivity which otherwise would be left
  behind.
• Limited reservoir communication, need for more
  drainage points.
• Mitigate gas breakthrough.

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Gullfaks Satelitter

• Prosjektforslag til Gullfaks Landsbyen 2006
• Innfasing av to små satelittfelt

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Situation in year 2001
Rimfaks Brent Production start year 2000.
Spring 2001 IOR possibility documented, 2 infill
wells extra gas handling capacity gives 2.1
MSm3 of extra oil.
GF Sør LM templates, prod.start Sept.2001. 3
flowlines to GFC for GF Sør Brent gas production.
Extra capacity and tie-in possibility at L/M for
upsides in GF Sør Field.
Prospects defined in the Brent Gp. and Statfjord
Fm. in the Ole, Dole and Doffen (ODD) segments.
(Later named Skinfaks.)
Skinfaks/Rimfaks IOR. RES/PRO-seminar,
23.-24.November 2005.
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DG1 team establ.
Scr. ph. 1
Screen.phase 2
Scr. ph. 3
Scr. Ph. 5
Scr. Ph. 4
DG1 (BoK)
DG2 (BoV)
DG3 (BoG)
PDO del.
33/12-8S
Feasibility study phase

• 11 variants of concept SRI to GFC via L/M
  (re)evaluated
• - 1 or 2 templates, 1 or 2 satellites, 1 or 2
  flowlines.
• - Further optimising of subsea wellhead locations
  and subsea/pipeline cost.
• - Increased volumes (3.RF well, Skinfaks N1
  segment, Skinfaks gas lift)
• Upside volumes quantified, value (risked)
  calculated.
• Selection criteria NPV (and then IRR and
  NPV/CAPEX disc.)

To L/M
Recommendation from Project, February 2004
Optimise concept 2SX (1 template, 1 satellite,
2 flowlines) further towards DG2.
Upside well
Basis well
Skinfaks/Rimfaks IOR. RES/PRO-seminar,
23.-24.November 2005.
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Økt utvinning

• Innfasing avsegment N0 N1

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N0 og N1
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Innfasing av N0 og N1

• Reserver, produksjonsprofiler
• Antall brønner, produksjonsutfordringer
• Usikkerheter, økonomi

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Gullfaks Satelitter Prosjektforslag til
Gullfaks Landsbyen 2006 Gel for WC reduksjon i
GF produsenter

• Metodikk

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Gelling reaction in water phase only
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Flømming med vann / viskøst vann
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Gel system- an intermediate system between
weak and blocking
Polymers ------ emulsion ----------blocking
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Gelation time versus formation temperature
Injection of 130 m3 at injection rate of 0.9
m3/min means gelation time gt 2.5 hours
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A-16 before/after DPR
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Methods for reducing sand production

• A gel will act as glue between sand grains
• Consolidation of loose sand
• Some permeability reduction
• Permeability reduction can be controlled (minimum
  reduction in water permeability)
• Increased sand free production rate
• As a result increased production rate with the
  potential of reduced water-cut

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Oppgave - stikkord

• Typer gel
• Tilbakeproduksjon/miljø
• WC, perm, sonevisLagdelte reservoarer
• Injeksjonsvolum
• Ønsket plassering
• Finne egnet brønn på GF