X-Stream Gas Transport Concept Rev

Asle Venas, Director Pipelines

20 Jan 2012

X-Stream Gas transport concept

Press conference, London

Det Norske Veritas AS. All rights reserved.


20 Jan 2012

The challenge

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An increasing challenge:

Long distance gas transport-ation in deep waters

More and more harsh environment

The time of easy oil is over



20 Jan 2012

Deepwater and ultra-deepwater gas pipelines

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Large diameter Thick wall:

Difficult to produce Limited number of pipe mills Heavy pipes difficult

handling and logistics

Difficult to weld

Extremely thick and costly buckle arrestors

Limited number of pipe-lay vessels



20 Jan 2012

X-Stream

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Idea:

Reduced wall thickness of long distance deepwater gas pipelines by controlling the differential pressure

The objective:

Reduce the cost of deepwater gas pipelines within current safety regime

About X-Stream:

A DNV innovation project



20 Jan 2012

X-Stream

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Codes and standards:

The new concept fulfills common pipeline

codes like ISO and DNV-OS-F101

Basis:

The concept is based on a combination of already established and field proven technology in an innovative way



20 Jan 2012

X-Stream

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Inspired by the HIPPS concept There are already more than 20 HIPPS systems in use worldwide today



20 Jan 2012

Video 1

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X-Stream

In order to control the differential pressure

DNV introduces

i-HIPPS (Inverted-HIPPS)

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20 Jan 2012

Video 2

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20 Jan 2012

X-Stream main principle in a lifecycle perspective

1. Install pipeline water filled fully or partly

2. Carry out normal flooding, cleaning and gauging of the pipeline

3. Dewater and dry the pipeline

4. Maintain a certain minimum internal pressure in the pipeline during the entire life of

the pipeline by use of i-HIPPS

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20 Jan 2012

Example

Product: treated associated gas (pipeline export)

Distance to shore: 400 km

- 300 km in deep waters

- 100 km in shallow waters

Water depth: 3,000 meters (ultra-deep waters)

Pipeline export:

- Diameters analysed: 4 off (18, 24, 28 and 32)

- Installation method: J-lay

- Installation: Partially water-filled

- Safety Class: Medium

- Operational pressure: 250 bar

- Minimum internal pressure: 200 bar (in i-HIPPS area)

- With and without concrete coating (specific gravity

1.1)

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Installation

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Collapse Depth

Flood Level

Factor of Safety

Seabed

Level

Empty Pipe

Flooded Pipe



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Required wall thickness

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Top tension vs. flooding level

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Reduced wall thickness Example for 18 diameter

Pipeline data Traditional

pipeline

X-Stream

without

concrete

X-Stream

with concrete

OD (m) 0,457

0,457 0,457

Wall thickness (mm) 25

17 16

Concrete thickness (mm)

minimum 12

Wall thickness saving 32% 36%



20 Jan 2012

Reduced costs four diameters

Reduced cost due to less steel required

Reduced installation costs due to reduced welding times

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-40 %

-35 %

-30 %

-25 %

-20 %

-15 %

-10 %

-5 %

0 %

18" 24" 28" 32"

-32 %-30 % -29 %

-28 %

-36 % -36 % -37 % -37 %

X-Stream without Concrete

X-Stream with Concrete



20 Jan 2012

How can the X-stream concept work safe and reliable?

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20 Jan 2012

i-DBB concept

DNV has run a concept risk analysis and one major issue came up:

There will at least be required to have a 100% leak tight secondary valve as a leak or rupture may take time to repair.

- We have therefore also developed a very simple and reliable system that will give a 100%

internal leak tight valve.

- The system is an inverted double-block-and-bleed system we call i-DBB

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Video 3

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Main benefits

Reduced steel quantity

More pipe mills can deliver linepipe

Easier to manufacture higher grades

Reduced weight of linepipe

Reduced welding times

Increased lay rates

May not need buckle arrestors

Equal safety level

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Some of the planned deepwater pipelines

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Conclusion

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Fulfils common pipeline codes and standards, i.e. ISO and DNV-OS-F101

Based on established and field proven technology combined in an innovative way

A safe and reliable system that ensures significant savings in terms of wall thickness, handling and installation time



20 Jan 2012

Safeguarding life, property

and the environment

www.dnv.com

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X-Stream Gas Transport Concept Rev

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