How to find field candidates for enhanced

How to find field candidates for enhanced
recovery by water additives on the NCS
Enhanced Recovery by water additives
FORCE Seminar 08. 02. 2007
Jan Bygdevoll, Principal Engineer, NPD
Š Why is a field a candidate for enhanced recovery ?
Š Because there is more oil to potentially be recovered than by methods
applied today
Š What is a method for enhanced recovery ?
Š Anything that increase (or enhance) the recovery of oil (or gas) from a field
Š Injection methods
Š
Š
Š
Š
Water
Gas, including CO2
Combination (WAG)
Additives to injected water
Surfactants
Polymers
Other ?
08.02.07
2
Norwegian Oil production
RNB2006
Oljeproduksjon, Norsk kontinentalsokkel
Alle ressurskategorier
Uoppdagede ressurser
Ressurser i funn
Ressurser i felt
Reserver
Faktisk
200
180
160
Produsert per 31.12.2005: 3,0 GSm3
Gjenværende reserver: 1,2 GSm3
Ressurser i felt:
0,4 GSm3
Ressurser i funn:
0,1 GSm3
Uoppdagede ressurser: 1,2 GSm3
140
MSm3
120
100
80
60
40
20
0
1970
1980
1990
2000
2010
2020
2030
M:\ La g\ D-Re ssAna lyse \ EKM\ Tot a lprod.xls
08.02.07
3
Oil production – prognosis to 2011 (RNB 2007)
200
Ressurser i funn/Resources in discoveries
Ressurser i felt/Resources in fields
Reserver/Reserves
3.0
Historisk produksjon/Actual production
2.0
100
millioner fat per dag
million barrels per day
millioner Sm³
3
million Sm
150
1.0
50
0
0.0
1995
08.02.07
1997
1999
2001
2003
2005
2007
2009
2011
4
Oil profiles for Norwegian fields
200
180
160
Rest
140
Balder
Norne
120
MSm3
Ula
Draugen
100
Heidrun
80
Oseberg
Grane
Troll
Grane
60
Valhall
Gullfaks
Snorre
Eldfisk
40
Statfjord
20
Ekofisk
0
1980
08.02.07
1985
1990
1995
2000
2005
2010
2015
2020
2025
5
Status for NPD’s goal on Reserve
Growth for Oil 2005 – 2015
800
G o a l fo r re s e rve g ro w th
P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th to ta l
700
P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th in e x is tin g fie ld s
C u m u la tive re s e rve g ro w th in to ta l
600
C u m u la tive re s e rve g ro w th fro m e x is tin g fie ld s
Mill Sm3
500
400
300
200
100
0
2 0 04
08.02.07
20 0 5
2006
2 0 07
2 00 8
2009
2 01 0
20 1 1
20 1 2
2 0 13
20 1 4
6
Status for NPD’s goal on Reserve
Growth for Oil 2005 – 2015
G o a l fo r re s e rve g ro w th
P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th to ta l
800
P ro g n o s is a u tu m n 2 0 0 4 fo r re s e rve g ro w th in e x is tin g fie ld s
C u m u la tive re s e rve g ro w th in to ta l
C u m u la tive re s e rve g ro w th fro m e x is tin g fie ld s
700
R N B 2 0 0 6 O p e ra to rs p ro g n o s is
R N B 2 0 0 7 O p e ra to rs p ro g n o s is
600
Mill Sm3
500
400
300
200
100
0
2004
08.02.07
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
7
08.02.07
Troll I
Gullfaks
Oseberg
Statfjord
Heidrun
Snorre
Valhall
Eldfisk
Hod
Åsgard
Tordis
Gyda
Alvheim
Vigdis
Veslefrikk
Visund
Norne
Oseberg Øst
Snøhvit
Draugen
Ula
Kristin
Balder
Brage
Vest Ekofisk
Grane
Njord
Gullfaks Sør
Tor
Oseberg Sør
-200
Troll II
Ekofisk
MSm³
Produced, yet to produce and oil remaining in
ground based on current plans
600
400
200
0
-400
Remaining oil in ground at planned cessation
Produced oil end 2006
Remaining oil reserves
-600
8
Produced, yet to produce and oil remaining in
ground based on current plans
600
400
MSm³
200
0
-200
Chalk reservoir
Sand reservoir w/ water inj
Sand reservoir w/ gas inj
-400
Remaining oil in ground at planned cessation
Produced oil end 2006
Remaining oil reserves
-600
08.02.07
9
Produced, yet to produce and oil remaining in
ground based on current plans
120
100
80
60
40
MSm³
20
Volve
Urd
Mime
Tambar
Glitne
Jotun
Tyrihans
Yme
Varg
Kvitebjørn
Statfjord Øst
Albuskjell
Frøy
Embla
Fram
Hod
Åsgard
Tordis
Gyda
Alvheim
Vigdis
Veslefrikk
Visund
Norne
Statfjord Nord
-40
Oseberg Øst
-20
Snøhvit
0
-60
Remaining oil in ground at planned cessation
Produced oil end 2006
Remaining oil reserves
-80
-100
08.02.07
10
Development in recovery factor
grouped by field seize
Recovery Factor Oil (%)
60
50
40
30
NB! The number of fields varies with time
20
1992
08.02.07
1993
1994
1995
1996
1997
1998
1999
<15 million Sm3 oil
> 50 million Sm3 oil
15 - 50 million Sm3 oil
Average all fields
2000
2001
2002
2003
2004
2005
2006
11
Recovery factor versus Reservoir Complexity
Index (RCI) – a tool for estimating potential ?
0.70
y = -0.776x + 0.7779
2
R = 0.8095
0.60
0.50
Utv grad
0.40
0.30
0.20
0.10
0.00
0.10
08.02.07
0.20
0.30
0.40
0.50
RCI
0.60
0.70
0.80
0.90
12
Reservoir Complexity Index (RCI)
– parameters used in evaluation
Complexity score
Complexity
attribute
Description
Low complexity
1
Average
permeability
Describes the pore volume weighted
average permeability in the main
flow direction of the defined
reservoir. mD
> 10.000
Permeability
contrast
Describes the permeability contrast
between geological layers/facies
types, and is calculated as
log10[Kmax/Kmin]
<1
Structural
complexity
Describes how fluid flow between wells
is affected by fault density, fault
throw, fault transmissibility, ….
Lateral stratigraphic
continuity
Describes the stratigraphic continuity of
the flow units in the main flow
direction within the defined
reservoir
STOOIP density
Describes the areal concentration of
STOOIP and is defined as
STOOIP/area
(mill. Sm3/km2)
Coning tendency
08.02.07
Describes the coning problems
associated with a gas cap or
aquifer support. Large complexity
only in cases where the oil band
is thin.
High complexity
2
100010
00
0
1-2
3
4
5
100-1000
10-100
< 10
2-3
3-4
>4
The fault properties restrict
fluid flow significantly.
(High density of faults
with throw larger than
reservoir thickness
and/or 'zero'
transmissibility).
The fault properties
does not restrict
fluid flow.
Highly discontinuous.
Difficult to
predict/describe
injector/producer
connecting flow units.
High degree of
continuity
>4.5
No coning tendency.
2 - 4.5
1-2
Some coning
problems
from gas
cap or
aquifer
0.5 - 1
< 0.5
Thin oil zone and production
severely restricted by
gas or water coning
problems
13
Important issues in estimating potential for
different methods to increase recovery
Š How is the remaining oil distributed in the reservoir?
Š Temperature
Š Fluid chemistry
Š Mineralogy
Š Topside facilities and wells
Š Cost, both investment and operational
Š Remaining field life
Š Other issues
08.02.07
14
160
140
120
80
60
Frigg
Snøhvit
Odin
Troll
Alvheim
Alvheim
Balder
Alvheim
Draugen
Gullfaks
Gullfaks
Gullfaks
Heimdal
Grane
Balder
Gullfaks
Glitne
Tordis
Tordis
Snøhvit
Jotun
Tordis
Heidrun
Skirne
Statfjord
Valhall
Statfjord Øst
Snorre
Tordis
Urd
Snøhvit
Sleipner Øst
Gullfaks Sør
Statfjord
Hod
Snorre
Statfjord Nord
Ormen Lange
Mikkel
Brage
Statfjord
Sygna
Statfjord Nord
Norne
Gullfaks Sør
Sigyn
Sigyn
Hod
Frøy
Gullfaks Sør
Visund
Njord
Njord
Gullfaks Sør
Sleipner Vest
Gullfaks Sør
Lille-Frigg
Vale
Varg
Gullfaks Sør
Cod
Vest Ekofisk
Ekofisk
Edda
Albuskjell
Ula
Huldra
Kvitebjørn
Kristin
Tambar
Embla
Mime
Kristin
100
Deg. C
Reservoir temperature in fields on NCS
180
40
20
0
Fields
15
08.02.07
Methods to improve injection ?
To obtain better sweep
and produce by-passed oil ?
To reduce the
residual oil saturation in
the swept sone?
Economical issues
Environmental issues
08.02.07
16
Oil cost curve, including technological progress:
availability of oil resources as a function of price
08.02.07
17
Cost and potential of Surfactant compared
with other methods to increase recovery
08.02.07
18
Potential for surfactant flooding ?
Š In 1991 a work group in Statoil, Hydro a Saga and NPD
estimated a technical potential from 80 to 130 MSm³
Š Based on an Sorw > 0.25 and immediate startup in 10 reservoirs
Š ”Profitable reserves (potential)” was estimated to 55 to
87 MSm³ including the condition of
Seff > 40 Sm³ oil/ton surfactant
Journal of Petroleum Science & Engineering, April 1992
Š What have16 years done to the potential?
Š Is it time for a new potential study?
08.02.07
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