4.1 Introduction

Much of the last 50 years of global offshore oil and gas experience can be applied to an offshore CCS project. However, it is as important to understand what cannot be transferred, as it is to understand what can.

Oil and gas operations involve producing, processing, and exporting fluids which are essentially hydrocarbon mixtures together with a saline water phase. CCS involves handling a relatively pure component having distinctly differing phase behaviour characteristics and injecting it into a reservoir formation.

Section 2 explains some of the peculiarities of CO2 from a CCS perspective, and the reasons for the importance of the differences between this and natural gas, especially with regard to safety. Section 4 addresses this point and highlights some of the existing deep sea features that can be applied directly to offshore CCS pipelines and facilities.

Helpfully, many of the existing guidance documents, manuals and regulations originally produced for the offshore oil and gas industries have direct relevance to CCS applications. These include:

- Status of technical guidance and information on design, construction and operation of offshore installations61

- Prevention of Fire and Explosion and Emergency Response (PFEER) on offshore installations62

- Safety Case Regulations63.

- Guidance note 2/200664

- Guidance note 3/200665

- Assessment Principles for Offshore Safety Cases (APSOC)66

- Guidance for the Topic Assessment of the Major Accident Hazard Aspects of Safety Cases (GASCET)67

- Safety Case Assessment Manual (SCAM)68

- HID/OSD/Tech/SPC3069

- HVAC guidelines70

- ISSO Standard 31000: Risk Management – Principles and Guidelines71

- Design and Construction Regulations (DCR)72

- Pipeline Safety Regulations (PSR)73

- Provision and Use of Work Equipment Regulations (PUWER)74

Caution needs to be applied when using these guidance documents, manuals and regulations, because unless their use is coupled with an understanding of the differences between CO2 and the fluids associated with offshore production, designers can end up applying these codes out of context. This can lead to unnecessary expenditure, over-restrictive operating practices or inappropriate design margins.

61 Status of technical guidance and information on design, construction and operation of offshore installations HSE Operations Notice 27, issued September 2003, revised October 2010

62 Prevention of Fire and Explosion and Emergency Response (PFEER) on offshore installations (1995) SPC/ Enforcement/155

63 The Offshore Installations (Safety Case) Regulations 2005, 2005 No. 3117

64 Guidance note 2/2006 (Offshore Installations (Safety Case) Regulations 2005, Regulation 12 Demonstrating compliance with the relevant statutory provisions), Health and Safety Executive 2006.

65 Guidance note 3/2006 (Offshore Installations (Safety Case) Regulations 2005, Guidance on Risk Assessment for Offshore Installations'), Health and Safety Executive 2006.

66 Assessment Principles for Offshore Safety Cases (APSOC), Health and Safety Executive, March 2006

67 Guidance for the topic assessment of the major accident hazard aspects of safety cases, Health and Safety Executive, April 2006.

68 Safety Case Assessment Manual, Gas Safety Management Regulations 1996, HSE Hazardous Installations Directorate Gas & Pipelines Unit, Version 6, 03 June 2011.

69 HID/OSD/Tech/SPC30, Indicative human vulnerability to the hazardous agents present offshore for application in risk assessment of major accidents, Health and Safety Executive, Version 3, issued 1 November 2010.

70 ISO 16813:2006 Building environment design, Indoor environment, General principles

71 ISO 31000:2009: Risk Management – Principles and Guidelines

72 Offshore Installations and Wells (Design and Construction, etc) Regulations 1996 SI 1996/913 HMSO 1996 ISBN 0 11 054451 X.

73 A guide to the Pipelines Safety Regulations 1996, L82, ISBN 0-7176-1182-5.

74 Provision and Use of Work Equipment Regulations 1998. Approved Code of Practice and guidance L22 (Third edition) HSE Books 2008 ISBN 978 0 7176 6295 1.