Tail production:
Choosing the right strategy for
Produced Water Management
K.I. Andersen
Produced Water Daily Volumes








Statfjord
Gullfaks
Snorre
Tordis/Vigdis
Veslefrikk
Heidrun
Norne
Åsgard
160 000 m3/d
75 000 m3/d
25 000 m3/d
15 000 m3/d
15 000 m3/d
10 000 m3/d
2 000 m3/d
500 m3/d
300 000 m3/d of produced water..
Mars April 2004
Oil rate development 2003 vs 1998
All GF and SF wells
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
169
161
153
145
137
129
121
113
105
97
89
81
73
65
57
49
41
33
25
17
9
1
0
Water rates pr. well 2003 vs 1998
All GF/SF
6000
5000
4000
3000
2000
1000
169
161
153
145
137
129
121
113
105
97
89
81
73
65
57
49
41
33
25
17
9
1
0
Increased watercut : scale, reinjection, water
shutoff, downhole separation
Environmental impact (EIF) at Statfjord C
EIF Statfjord C
H2S
scavenger
3%
Corrosion
inh.
82 %
Oil comp.
15 %
Environmental impact (EIF) at Gullfaks A
Gullfaks A 2002
Methanol
1,6 %
Glycol
2,1 %
Oil components
19,1 %
H2S scavenger
77,0 %
Other comp
0,2 %
Produced Water Management
Produced water
treatment
Re-injection
Water shut off
Authorities, Produced Water and
Environment:
Reduced Tolerance
vs.
Produced Water Handling Principles
1. Improve use of chemicals
2. Reduce at source
Isolate water producing zones (plug,
patch, gel)
Intelligent completions
Downhole separation
3. Reinject
Produced water reinjection
in active reservoir
4. Store
Utsira or depleted/non active areas of
field
5. Purifiy before discharge
CTour, EPCON etc
§1.
Reduce chemical consumption
or change to non-toxic
H2S-removal by use of scavenger

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
§ 2.
Shut off waterproduction at source
Well completion type dictates water
shutoff complexity
Cased
Screen
Horizontal, screen
Horizontal, cased
Main Well Categories in Statoil
(total +-700 wells)
Complexity,
zonal isolation
Openhole horizontal
Perforated, cemented, horiz.
Openhole, deviated
Perforated,cement
deviated
10 %
25%
5%
60 %
tfj
tfj
or
d
or
d
or
d
tfj
C
B
A
Pl
08
Sn
9
or
re
TL
P
No
rn
e
Vi
su
nd
SF
SA
G
T
ul
lf a
ks
G
A
ul
lf a
ks
G
B
ul
lf a
ks
Ve
C
sl
ef
r ik
k
A
He
id
ru
n
St
a
St
a
St
a
m3/d
- Cumulative annual water shut off
25 000 m3/d
Shut off waterproduction 2002
6000
5000
4000
3000
2000
1000
0
Ongoing R&D : Revisiting chemical route
to water shutoff
Chemical water shutoff/Emulsified gel
technology
RRFw
1,E+04
”Strong gel”
e.g. H2Zero
RRF
1,E+03
1,E+02
RRFo
DPR”Classic”
i.e. polymer
1,E+01
1,E+00
0
0,2
0,4
0,6
Saturation
0,8
1
Rate effects of changing PI and WC
R&D 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.
Future :
Subsea Separation and PWRI
§3. Reinject water (PWRI)
A-43 PWRI performance
W ellh ead Pressu re v Rate
Heid ru n Åre-2 I W ater In jectio n W ell A-43
220
200
WHP (bar)
180
160
140
120
100
80
60
SWI
PWRI
40
1000
1500
2000
2500
Rate (m3/d )
3000
3500
4000
Statfjord field map
pilot well
- Today reinjecting 30 000 m3 of water
R&D - PWRI Fracture growth : improving
our modelling capability
§3. Dispose into aquifer
Utsira – a shallow saltwater
reservoir
Extent of Utsira aquifer
- Kvitebjørn to dispose all produced
water into Utsira
§4. Purify and discharge
Distribution of organic components in
produced water
WAF= Water accommodated fraction
The CTour process
Results from CTour test at Statfjord B
2-3 ring PAH removal
Removal Efficiency (%)
Removal efficiency (%)
C4-C5 Phenols Removal
100
80
60
40
20
0
0
0.25
0.5
0.75
1
1.25
1.5
1.75
80
60
40
20
0
0
0.25
0.5
0.75
1
1.25
1.5
1.75
Vol % Condensate Injection
Vol% Condensate Injection
Dispersed oil removal
These component groups are together with our
corrosion inhibitor the largest contributors to
EIF
100
Removal efficiency (%)
100
80
60
Blue line system performance (with
hydrocyclones), red line effect of condensate
and mixers only
40
20
0
0
0.25
0.5
0.75
1
1.25
Vol% Condensate Injection
1.5
1.75
Questions?