The Safe Transfer of Liquefied Gas in an Offshore Environment (STOLGOE) (eBook)

Published Date

October 2010

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The Safe Transfer of Liquefied Gas in an Offshore Environment (STOLGOE) (eBook)

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These Guidelines address the transfer of Liquefied Petroleum Gas (LPG) between Floating (Production) Storage and Offloading facilities (F(P)SOs) and conventional gas tankers. The guidelines are primarily intended to familiarise Masters, ship operators, F(P)SO operators and project development teams with the general principles and equipment involved in LPG offloading activities between F(P)SOs and gas tankers.

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The guide primarily addresses side-by-side (SBS) operations where the gas tanker moors alongside the F(P)SO. LPG is also offloaded to gas tankers offshore in other modes, such as via an SPM or in a tandem configuration. These operations are considered in depth in other OCIMF publications associated with oil transfers. Within this publication, only the differences associated with gas transfer have been highlighted.

To address site-specific aspects in particular locations, the recommendations contained within this publication may be supplemented by additional requirements from development project teams, individual ship owners (or ship managers) and individual F(P)SO operators.

Individual countries may have local regulations that address mooring arrangements and LPG cargo transfer operations within their territorial waters or Exclusive Economic Zone. These must be complied with and, where appropriate, these Guidelines may be referenced for additional advice. These Guidelines should not be considered contrary to, or a replacement of, any National or International Regulations or individual terminal operator’s specific procedures.

This publication primarily addresses the inter-relation between the F(P)SO and conventional gas tankers operating in SBS mooring configuration. The guidance includes recommendations for mooring equipment, considers mooring loads and operations, motions of the F(P)SO and gas tanker, station keeping, cargo transfer equipment and cargo transfer operations. The guidelines are intended to assist in standardising equipment and procedures for SBS activities and to highlight general design issues in the interest of safe, efficient and reliable operations .

Offshore operations involving the transfer of Liquefied Natural Gas (LNG) are not specifically addressed in this document, but will be included in a future update once industry experience is available on which to base guidance.

For the purposes of these Guidelines, the gas tanker is considered to be a vessel equipped with standard mooring and cargo transfer equipment, with a conventional single propulsion system comprising of a fixed blade propeller.

Purpose and Scope
Glossary of Terms and Abbreviations

Section 1

Regulatory Compliance

1.1 General
1.2 Coastal State/Local Requirements
1.3 Flag State Requirements
1.4 Classification Society Requirements
1.5 Other Industry Guidance
Section 2
Safety in Design

2.1 General
2.2 Risk Analysis
2.3 Operating Environments
2.4 Model Tests and Simulations
2.5 Tug Support
2.6 Berthing Aids
2.7 F(P)SO Mooring System
2.8 F(P)SO Heading Control
2.9 Mooring Equipment Layout Configuration and Compatibility
2.10 Fendering Equipment
2.10.1 Primary Fenders
2.10.2 Secondary Fenders
2.11 Cargo Transfer Equipment
2.11.1 Hoses
2.11.2 Hard Arms
2.11.3 Quick Connect/Disconnect Couplings (QC/DC)
2.11.4 Gas Tanker Manifold Arrangements
2.12 F(P)SO Venting Systems
2.13 ESD Systems
2.14 Emergency Release Couplings
2.14.1 Location of ERC
2.15 Quick Release Capability of Moorings
2.15.1 Fixed Quick Release Hooks
2.15.2 Portable Quick Release Hooks
2.15.3 Use of Grommets
2.15.4 Use of Tugs in an Emergency
2.16 Lighting
2.17 CCTV
Section 3
Operational and Personnel Safety

3.1 Operational Safety
3.1.1 F(P)SO Operator’s Responsibilities
3.1.2 Scope and Content of F(P)SO Terminal Handbook
3.1.3 Simultaneous Operations
3.1.4 Communications
3.2 Personnel Safety
3.2.1 F(P)SO Manning
3.2.2 Training of F(P)SO Personnel
3.2.3 Competence Assurance of Key Personnel Involved in Operation
3.2.4 Gas Tanker Personnel
Section 4
Nomination and Pre-Arrival Procedures

4.1 Nomination Procedures
4.1.1 Vetting
4.1.2 Facility/Tanker Compatibility
4.2 Pre-Arrival Communications
4.2.1 Transfer Area
4.3 Pre-Arrival Checklists and Testing of Essential Systems
4.4 Tugs and Support Vessels
4.5 Mooring and Fendering Plan
Section 5
Berthing and Mooring

5.1 Personnel and Equipment Transfer
5.1.1 Transferring Personnel
5.1.2 Transferring Equipment
5.2 Pre-Berthing Inspection
5.3 Pre-Berthing Information Exchange
5.4 Pre-Berthing Equipment Checks
5.5 Use of Tugs
5.6 Berthing Criteria
5.7 Manoeuvring
5.7.1 Thruster Influence
5.8 Mooring
5.9 Transfer of Personnel and Equipment Alongside
5.10 Orientation of F(P)SO for SBS Operations
Section 6
Cargo Transfer

6.1 General
6.1.1 Pre-Transfer Checklists
6.2 Cargo and Ballast Plans
6.2.1 Cargo Plans
6.2.2 Ballast Plans
6.3 Pre-Transfer System Integrity Checks
6.4 Hose/Arm Handling and Connection
6.4.1 General
6.4.2 Drying and Inerting the Transfer System
6.4.3 Bolted Flanges
6.4.4 QC/DC Couplings
6.4.5 Emergency Release Couplings (ERCs)
6.4.6 Loading Arms
6.4.7 Leak Testing the Transfer System
6.5 Sampling and Gauging
6.5.1 General
6.5.2 Product Measurement
6.5.3 Sampling
6.6 Cargo Transfer
6.7 Control of Vapours
6.8 Hose/Arm Clearing
6.8.1 General
6.8.2 Hose Draining
6.8.3 Hose/Arm Clearing with Hot Gas
6.8.4 Hose/Arm Clearing with Nitrogen
6.9 Hose/Arm Disconnection and Recovery
Section 7
Unmooring and Departure

7.1 Early Departure Procedure
7.2 Unmooring and Departure
Section 8
Gas-Up and Cool-Down

8.1 General
8.2 Gas Tanker
8.2.1 Gas Tanker with Tanks under Air
8.2.2 Gas Tanker with Tanks under Inert Gas
8.2.3 Loading Propane Cargo into Tanks under Butane Vapours
8.3 F(P)SO
8.3.1 Preparation and Arrival on Location
8.3.2 Use of Gas Tanker
8.3.3 Use of Supply Source for Gassing-up F(P)SO
Section 9
Offshore Transfer of LPG VIA Tandem Mooring or SPM

9.1 Primary References and Scope
9.2 Safety in Design
9.2.1 Mooring Equipment Layout, Configuration and Compatibility
9.2.2 Cargo Transfer Equipment
9.2.3 Equipment Evaluation
9.3 Operational Issues
Section 10
Emergency Preparedness

10.1 Overview
10.1.1 General
10.1.2 Emergency Plan Components and Procedures
10.1.3 Communications and Alarms
10.2 Emergency Scenarios
10.2.1 Power Failure on F(P)SO, Gas Tanker or Tug
10.2.2 Collision/ Heavy Contact
10.2.3 Grounding in Approaches to or within the Field
10.2.4 Loss of Containment
10.2.5 Uncontrolled Venting
10.2.6 Fire and Explosion
10.2.7 Hose/Arm Failure
10.2.8 Mooring Failure
10.2.9 Fender Breakaway or Burst
10.2.10 Medical Evacuation
10.2.11 Helideck Incident
10.2.12 Oil Pollution
10.2.13 Security Incident
10.3 Drills and Training
A Example Content of Terminal Handbook (Port Information Book)
B Example SIMOPS Matrix
C Example Gas Tanker Nomination Questionnaire
D Check-Lists
D1 Example Record of Pre-Transfer Meeting
D2 Example of F(P)SO Pre-Berthing Check-List
D3 Example of Ship/F(P)SO Safety Check-List
D4 Example Pre-Unberthing Check-List

OCIMF was formed in April 1970 in response to the growing public concern about marine pollution, particularly by oil, after the Torrey Canyon incident in 1967. In the early 1970s, a variety of anti-pollution initiatives were starting to emerge nationally, regionally and internationally, but with little coordination. Through OCIMF, the oil industry was able to play a stronger, coordinating role in response to these initiatives, making its professional expertise widely available through cooperation with governments and intergovernmental bodies.

OCIMF was granted consultative status at the IMO in 1971 and continues to present oil industry views at IMO meetings. Since then, its role has broadened to take account the changing maritime activities of its membership. Its remit now covers tankers, barges, offshore support vessels and terminals and its advice extends to issues like shipping in ice and large-scale piracy, which rarely troubled the oil industry when OCIMF was first created in the 1970s.

The current membership of OCIMF comprises 112 companies worldwide.

Today, OCIMF is widely recognised as the voice of the oil industry providing expertise in the safe and environmentally responsible transport and handling of hydrocarbons in ships and terminals and setting standards for continuous improvement. Membership is extensive and includes every oil major in the world along with the majority of National Oil Companies.

OCIMF has much to be proud of. Not only has it contributed to a substantial quantity of regulation at the IMO aimed at improving the safety of tankers and protecting the environment, but it has introduced important new guidance on pressing current issues such as piracy and Arctic shipping. With the process of introducing new Internationally-accepted regulation necessarily slow as it crosses many individual countries and jurisdictions, OCIMF is in the unique position of being able to leverage the expertise of its membership to press ahead with much needed guidance on important industry issues. This provides the means to improve practices in the membership and in the wider industry, and serves as a valuable reference for developing regulation.

Title: The Safe Transfer of Liquefied Gas in an Offshore Environment (STOLGOE) (eBook)
Number of Pages: 116
Product Code: WS1253EA
ISBN: ISBN 13: 978-1-85609-400-9 (9781856094009), ISBN 10: 1-85609-400-6 (1856094006)
Published Date: October 2010
Author: Oil Companies International Marine Forum

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