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

800.0

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)