Post on 02-Jan-2016
Ruben Schulkes
2007-08-23
Self-similarity and the need for subsea technology
rms • Date: 2007-07-24 • Page: 2
Outline of presentation
Trends & challenges Technological needs Research needs
rms • Date: 2007-07-24 • Page: 3
Trends
Since the early 80’s the global production rate has exceeded discoveries
Number of new discoveries of Giant and Super Giant fields (Ultimate Recoverable Resource (URR) > 500Mbbl) decreases
Is global oil production about to peak?
?
rms • Date: 2007-07-24 • Page: 4
Self-similarity? Production histories from selected oil provinces look very similar This self-similarity may suggest an eminent peak in global oil production Increasing focus on
- Increased Oil Recovery
- production from small fields (URR<50Mbbl)
- Heavy (ultra-heavy) crudes
US
Norway
North Sea
rms • Date: 2007-07-24 • Page: 5
Potential IOR in large fields
Average recovery factor in NCS is less than 50% Total volume of unrecoverable reserves > 3000 MSm3 oil (~5 x GDP)
rms • Date: 2007-07-24 • Page: 6
7900
8000
8100
8200
8300
8400
8500
0 5 10 15 20 25
Minimum field size (MSm3)
Cu
mu
lativ
e re
serv
es (M
Sm
3)
Small fields are challenging
59
63
78
98
60% more fields
5% m
ore
oil
Small fields do not contain much oil (by definition!) Development of small fields is only possible when
- Field development costs are low
- Operating costs are low
0.1
1
10
100
1000
10000
1 10 100 1000
Rank
Fie
ld s
ize
(M
SO
E)
rms • Date: 2007-07-24 • Page: 7
1
10
100
1000
10000
1 10 100 1000
Distance to prosessing unit (km)
Fie
ld s
ize
(M
so
e)
Subsea field developments Trends
- Development of smaller fields
- Development of large fields subsea-to-beach
Being able to predict what happens in flow lines and processing units is key to success- Further development of accurate simulation tools is crucial
2006-20101995-2000
2001-2005
rms • Date: 2007-07-24 • Page: 8
Current modelling approaches OLGA
- 1D frame work, pre-integrated 2D model for stratified flow
LEDA- Coupled 1D-3D simulator, 1D/2D for pipe flow, 3D for processing units
Fluent, StarCD, CFX- 3D codes
rms • Date: 2007-07-24 • Page: 9
CFD
- Reasonable on “short” length scales
- Difficulties with interacting dispersed phases and free boundaries
- Difficult closure relations (turbulence/dispersed phase interactions)
1D models- Difficulties on short length scales which influences long-scale phenomena
- Difficult to get closure relations which are universally valid
103 105 107L/D
CFD
101
Ph
ysic
al c
om
ple
xity
Hierarchy of models
1D models
Simplified 1D models
rms • Date: 2007-07-24 • Page: 10
Increased processor speed and algorithm improvements lead to speed-up of factor 1000 per decade in CFD codes
Demand for more accurate physical modelling leads to slow down of current 1D and future 2D simulators
- Pre-integrated models (use of turbulent velocity field information)
20202010 2015
Sim
ulat
ion
time
CFD
1D codes
Trends
rms • Date: 2007-07-24 • Page: 11
CFD simulation of 2-phase system- 30m pipe, 2x104 cells requires 5 days CPU time (4 processors) to simulate 30
second real time
Field case- 5km pipe, 1hr transport time
- 3x106 cells, 95040 days of simulation time
With speed-up factor of 1000/decade it becomes possible to perform real-time 3D transient simulation of 5km pipe within 20 years
300.0
400.0
500.0
600.0
700.0
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900.0
1000.0
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 30.0
Time [s]
Dens
ity
[k
g/m
3]
Naive application of CFD
rms • Date: 2007-07-24 • Page: 12
103 105 107L/D
FACE
101
Horizon/LEDA
Ph
ysic
al c
om
ple
xity
Multiphase research in Norway
Research is driven by industry and institutes Academic activity is scattered
- Who is doing the really difficult ground work?
- Where are the future researchers being educated?
Industry
rms • Date: 2007-07-24 • Page: 13
hydro.com
rms • Date: 2007-07-24 • Page: 14
Massively parallel simulations Use information from 1D/quasi-1D/2D codes as pre-conditioners for 3D
solution Multi-scale simulator
- Decouple high-frequency/short-length scale effects from low-frequency/long-length scale phenomena
Intelligent CFD
rms • Date: 2007-07-24 • Page: 15
Potential IOR in large fields (2)