Flare practice

1
Flare practice improvementon Gullfaks oil
field

• Magne BJØRKHAUG
• Ph.D.
• Adviser, Process safety, Statoil

2
Statoil operations in the North sea

• 60 of the produced oil and gas is operated by
  Statoil
• Gas and oil is transported through extensive
  pipelinesystem or through offshoretanker
  loading of oil
• Most new installations andsome of the old ones
  haveinstalled the flare gas recovery system

3
New flare modus implemented on Gullfaks in 1994
4
New flare practice on Gullfaks oil field

• One production mode - Two flare modes

Open and ignited flare
Closed flare system
5
Basic elements in the new flare system

• High integrity flare opening valve
• Flare gas recovery system
• Flare ignition system
• High quality safety system

6
Basic elements in the new flare system
Bursting Disc
To the flare stack with ignition system
LO
LO
HH
HH
PT
PT
HIPPS
FOV
XV
Flare gas recovery system
Sources
HP K.O. Drum
7
High integrity flare opening valve on Gullfaks
8
Ignition unit on Gullfaks C
Ignition unit
9
Flare practice improvement

• Environmental and economical improvements
• Reduces CO2 emission to the atmosphere
• Save CO2 tax
• Increase gas utilisation
• Increase the lifetime of the flare tip
• Reduces the need for purge gas in the flare system

10
Flare practice improvement

• Operational improvement to achieve the results
• A proper designed plant control system
• A proper planned plant maintenance system
• Recovery of gas from depressurisation of
  equipment
• Recovery of blanket gas

11
Flare practice improvement

• Avg. flare per year - Gullfaks C

12
Flare practice improvement

• Gullfaks C - Daily flare volume 2005

900
800
700
600
3
500
1000 Sm
400
300
200
100
0
01.01.2005
01.02.2005
01.03.2005
01.04.2005
01.05.2005
01.06.2005
01.07.2005
01.08.2005
01.09.2005
01.10.2005
01.11.2005
01.12.2005
13
Flare practice improvement

• Gullfaks C - Daily flare volume 2005

900
800
700
600
3
500
1000 Sm
400
300
200
100
0
01.01.2005
01.02.2005
01.03.2005
01.04.2005
01.05.2005
01.06.2005
01.07.2005
01.08.2005
01.09.2005
01.10.2005
01.11.2005
01.12.2005
A continues flare load of App. 50.000 m3/day is
added at the bottom
14
Estimates of reduced flaring

• Total flaring 2005 for Gullfaks C 26 656 m3/day
• Continues basic load App. 50 000 m3/day
• Estimated total flare load App. 75 000 m3/day
• Estimated reduction for Gullfaks C in 2005 60-70
  
• Average reduction in yearly flaring du to the
  no-flare technology is approximately 50 on
  Gullfaks during normal operation

15
Flare practice improvement
Gullfaks flare system 12 years after
The system have been operated without any major
problem for the operation time of 12 years. The
systems have been rebuilt to increase the
capacity due to tie-in of satellite
fields. Described in 1997 version of API 521.
Total savings in 12 years has been in the order
of 200 mill.