a step change in subsea installation

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Subsea Deployment Systems Ltd. A LOW RISK, LOW COST METHOD FOR THE INSTALLATION OF SUBSEA STRUCTURES A STEP CHANGE IN SUBSEA INSTALLATION

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Page 1: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

A LOW RISK, LOW COST METHOD FOR THE

INSTALLATION OF SUBSEA STRUCTURES

A STEP CHANGE IN SUBSEA INSTALLATION

Page 2: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

2

The Task

• Large structures

• Deep water

• Hostile environments

Page 3: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

3

Installation Problems

• Vessel capacity

• Weather restrictions

• Vessel availability

• Schedule constraints and delays

• Cost

Page 4: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

4

The Subsea Deployment System

• Simple, safe

• Water depth 80m to 3000m

• Capacity 100t to several 1000t

• Essentially independent of weather

• Low cost

Page 5: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

5

SDS Key Differences

• Structure connected to a buoyancy frame

• Submerged tow to site

• Payload depressed to seabed

• Negligible dynamic loading

• Very soft set-down

• No “point of no return”

Page 6: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

6

The Tool / System Main Components

PATENT

GB2464714

PCT/GB2009/051383

CONTROL CHAIN

CONTROL CHAIN TOWER

TOW CHAIN CLUMP WEIGHT

CASTLE

TOW BRIDLE

STRUCTURE

SOLID BUOYANCY

FULLY FLOODABLE

HULL

(OPTIONAL)

TRANSVERSE

SUPPORT FRAME

BALLAST LOCKER

Page 7: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

7

Control Chain Towers

Page 8: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

8

Dynamics

• Natural period > 120s

• Response < 20% of vessel motions (regular waves)

• Minimal dynamic loading

• Low set-down velocity (< 0.1m/s)

Page 9: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

9

Operating Window

Page 10: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

10

Operation

Tow

• Shallow surface tow

• Deep surface tow

• Transition

• Submerged tow

Page 11: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

11

Operation

Parking

• Lower clump

weight

• System floats

above seabed

Page 12: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

12

Operation

Installation

• Lower control chains

• Position

• Lower to seabed

Page 13: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

13

Operation

Ballast

• Install ballast weight to

balance the payload

weight

Page 14: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

14

Operation

Disconnect

• Activate release system

• Reconnect control chains

• Raise chains

Page 15: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

15

Inherent Safety

• Critical operations avoided offshore

• Operations can be suspended at any time

• Insensitive to weather changes

• Negligible dynamic loading

• Reduced risk of catastrophic failure

Page 16: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

16

Tank Test

Page 17: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

17

Summary

• Installation and decommissioning

• Basic proven technology

• Low risk / inherently safe

• High capacity

• Deep water & harsh environments

• Low cost

• Good solutions are simple

Page 18: A Step Change in Subsea Installation

Subsea Deployment Systems Ltd.

A STEP CHANGE IN SUBSEA

INSTALLATION