Recommended Practice for Corrosion Management of Pipelines in Oil & Gas Production and Transportation

Bijan Kermani

• Éditeur: CRC Press
• Année: 2017
• ISBN:
  9781351419475
• Édition: 1
• Sujet: Technology & Engineering
• Sous-sujet: Fossil Fuels

First Published in 2017. Pipeline integrity is key to maintaining operational success, safety and security and minimising harm to the environment. Corrosion is a dominant contributory factor to failures, leaks and integrity threats in pipelines. Therefore, its optimum control within an integrity management framework is paramount for the cost-effective design of facilities and ensuring continued, uninterrupted and safe operations within the expected design life.
This recommended practice (RP) is a compendium of current best practices and state-of-the-art knowledge by major operators, engineering contractors and service companies involved in hydrocarbon pro-duction and transportation. The RP incorporates some minimum operational requirements and practices to ensure that when man-aging corrosion in pipelines, fundamental principles are followed. It covers management of corrosion for pipelines carrying hydrocarbons, injection water and/or produced water from design to decommissioning. It is structured to follow the logical steps of a basic corrosion management process and makes references to relevant and available international standards and/or recommended practices. It is intended for use by personnel from the petroleum industry having knowledge of corrosion and materials.
It is hoped that this RP will prove to be a key reference document for engineers, suppliers and con-tractors working in the oil and gas industry, paving the way for corrosion-free operation of pipelines with the ultimate goal of improving safety, security and minimising the impact on the environment

1
Introduction

Pipeline corrosion management (PCM) is defined as that part of the overall pipeline management system (PMS) and operating practices which is concerned with the development, implementation, review and change of corrosion policy. In this recommended practice (RP), PCM covers the management of corrosion from design to decommissioning, for upstream pipeline systems carrying hydrocarbons, injection water and/or produced water. While numerous instances of pipeline leak and failure are reported annually, the challenge to managing their occurrences has not been reflected in the production of many international standards. This Chapter focuses on introducing the subject, outlines the objectives encompassing the scope of the RP and the benefits from the implementation of the PCM programme. It underlines necessary management commitment and competency requirements.

1.1 Foreword

Pipeline integrity is key to maintaining operational success, safety and security and minimising harm to the environment. Several industry surveys [1,2] have shown that corrosion is a dominant contributory factor to failures, leaks and integrity threat in pipelines. Therefore, its optimum control within an integrity management framework is paramount for the cost effective design of facilities and ensuring continued, uninterrupted and safe operations within the expected design life.

This RP is developed to improve and manage corrosion in upstream pipeline systems. It focuses on corrosion exclusively; both internal and external. However, other integrity threats should be considered and addressed within an appropriate Asset Integrity Management (AIM) programme to enable integrity and reliability assurance.

The risk of internal or external corrosion becomes real once an aqueous phase is present and able to contact the pipe wall, providing a ready electrolyte for corrosion reactions to occur. The inherent corrosivity of this aqueous phase is then heavily dependent on the pipeline materials of construction, environmental conditions (temperature, pressure, presence of bacteria, etc.) and levels of dissolved corrosive species (acid gases, oxygen, organic acids, etc.) which may be present.

Development, implementation and continual updating of a successful corrosion management framework are key components of operating a pipeline throughout its production life, whatever the operating conditions. As a consequence, it is important that an adapted and tailor-made corrosion management programme is put in place to actively manage corrosion from the earliest stages through to the end of pipeline life to ensure trouble-free operations. Such an approach needs to be taken on board and implemented in the technical/commercial assessment of new field developments, in prospect evaluation, and for operating existing pipeline systems.

The RP provides overview of elements, steps and measures necessary to manage corrosion of pipelines in oil and gas production and transportation. It has been developed from feedback of operating experience, research outcomes and operating companies’ in-house studies and practices. It has captured extensive inputs from operating companies, manufacturers, engineering contractors and service providers.

This RP is intended for use by personnel from the petroleum industry having knowledge of corrosion and materials and the necessary competency described throughout this document.

In the context of this RP, pipeline is defined as a line which carries fluids from wellheads or production sites to process sites (including platforms, reception plants, and downstream facilities) and vice versa, excluding wells, vessels, rotating equipment and process pipework.

This RP is not intended to provide a prescriptive framework for PCM, but only to outline, without going into details, the techniques, steps or measures which have been demonstrated as successful in the identification and management of the corrosion threats to oilfield pipeline facilities. It will also make reference to existing and recognised international standards whenever possible, without further details of their contents.

Furthermore, the present RP only provides a partial answer focused on corrosion threats of what needs to be developed within a broader theme of AIM.

By following the procedures outlined in this RP, confidence can be gained that the levels of corrosion control and management are appropriate for safe and trouble-free operations.

1.2 Objectives of this RP

This RP aimed to produce a reference document to achieve the following objectives:

• To capture and compile into a comprehensive document industry-wide information in relation to PCM.
• To define and outline common practices in PCM available amongst oil and gas operating companies and engineering design houses to:
  • ○ ease discussions with projects’ partners worldwide
  • ○ deal with third party tie-ins.
• To agree with engineering design houses on processes and approaches necessary to define and characterise corrosion management requirements at the design stage.

The RP should be treated as an integral part of a pipeline management system (PMS).

This RP includes:

1. Recommendations for registering essential and/or useful pipeline data for implementing adequate corrosion management programmes.
2. An overview of corrosion threats and their respective assessment practices.
3. Recommendations for defining and implementing corrosion mitigation actions.
4. An overview of corrosion monitoring data capture and full analysis.
5. An explanation for the need of adequate inspection programmes and their contribution to PCM programme.
6. Guidelines for an overall review process based on points (i) to (v) above.
7. Guidelines for change of duty if necessary from the review in step (vi).

The recommendations set out in this RP are meant to provide flexibility and must be used in conjunction with competent technical judgement. It remains the responsibility of the user of the RP to judge its suitability for a particular application.

Throughout this RP, the terms ‘should’ is used to indicate recommendations as opposed to prescriptive requirements.

1.3 Scope

1.3.1 General

This RP covers requirements and gives recommendations for managing corrosion from design to decommissioning in pipeline systems carrying hydrocarbons, injection water and/or produced water. It incorporates some minimum operational requirements and practices to ensure that fundamental principles are followed when managing corrosion in pipelines. It is intended for use in the technical/commercial assessment of new field developments, in prospect evaluation, design and construction, and for operating existing pipeline systems.

Table 1.1 and Fig. 1.1 summarise the scope of this RP, and present a list of excluded items/equipment where applicable. It should be noted that items within this RP include pig launchers and receivers.

Table 1.1 Scope of this RP

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