20602e00 Corrosion Integrity Management

Eni S.p.A. Exploration & Production Division

COMPANY STANDARD

CORROSION INTEGRITY MANAGEMENT

20602.VAR.COR.SDS November 2009

ENGINEERING COMPANY STANDARD Documento riservato di proprietà di Eni S.p.A. Divisione Agip. Esso non sarà mostrato a Terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato. This document is property of Eni S.p.A. Divisione Agip. It shall neither be shown to Third Parties not used for purposes other than those for which it has been sent.

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Exploration & Production Division PREMISE Rev. 0

November 2009

Eni S.p.A. Exploration & Production Division TABLE OF CONTENTS CORROSION INTEGRITY MANAGEMENT 1. GENERAL 1.1 Scope 1.2 References 1.2.1 ENI Company Standards 1.2.2 ENI E&P Company Documents 1.3 Acronyms and abbreviations 1.4 Glossary and definitions 2. 2.1 2.2 2.3

INTRODUCTION Asset integrity Corrosion Corrosion prevention and control

3. CORROSION INTEGRITY MANAGEMENT 3.1 Definition and targets 3.2 Tasks 3.3 Tasks and the project lifecycle 3.4 Tasks activities 3.4.1 Corrosion control philosophy 3.4.2 Materials and corrosion control design 3.4.3 Corrosion monitoring and inspection design 3.4.4 Laboratory and field testing 3.4.5 Data management 3.4.6 Corrosion management 3.4.7 Corrosion risk assessment 3.4.8 Risk-based Inspections 3.4.9 Corrosion monitoring and inspections 3.4.10 Asset integrity review 3.5 Main deliverables. Base requirements 3.5.1 Corrosion evaluation studies 3.5.2 Material Selection Reports 3.5.3 Cathodic Protection Specifications and Drawings 3.5.4 Corrosion Monitoring Design Specifications 3.5.5 Corrosion risk assessment studies 3.6 The Corrosion Integrity Workflow

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1. GENERAL 1.1

Scope

This document deals with Corrosion Integrity Management, intended as the general framework adopted by Eni E&P Division for managing and controlling the corrosion integrity of the assets. The aims of the document are: − to illustrate the workflow for the Corrosion Integrity Management during the project lifecycle; − to identify the tasks through which the goals of the Corrosion Integrity Management System are pursued; − to position the Corrosion Integrity Management tasks with respect to the development and operation project phases, from design through commissioning, start-up, operations, upsets and inactivity, life extension, if any, up to abandonment; − for each task, to identify the typical contents, input data and reference documents, output and deliverables; − for each task, to identify the applicable Company standards and other supports. The document does not cover the correlated activities not directly active within the project, as for instance: the management of Company standard; the personnel training and certification; the research and development activities. 1.2

References

1.2.1

ENI Company Standards

Ref. /1/

27605.DOC.GEN.SDS

Ref. /2/ Ref. /3/ Ref. /4/ Ref. /5/

06215.DOC.GEN.SDS 20189.COO.GEN.SDS 20198.COO.GEN.SDS 20203.COO.GEN.SDS

Ref. /6/

02555.VAR.COR.PRG

Ref. /7/

20603.MAT.COR.PRG

Ref. /8/ Ref. /9/ Ref. /10/ Ref. /11/ Ref. /12/

20019.MAT.COR.PRG 20312.VAR.COR.PRG 20000.VAR.PAI.FUN 27591.VAR.PAI.SDS 20550.PIP.COR.FUN

Ref. /13/ 20551.PIP.COR.FUN Ref. /14/ Ref. /15/ Ref. /16/ Ref. /17/

20554.PIP.COR.FUN 20552.VAR.PAI.FUN 20555.VAR.COR.PRG 20556.VAR.COR.FUN

Technical documentation required during the project development phase. Facility functional units. Technical document identification and title blocks. Item numbering. Handover of plant components data and key documents for DPIMP. Internal corrosion. Corrosion parameters and classification of the fluid. Material selection and corrosion control for oil and gas process equipment. (This standard cancels and replaces the previous ENI norms: 03588.MAT.COR.PRG, Internal corrosion. Material and material selection criteria; and 08053.MAT.COR.PRG, Materials and corrosion control methods in gathering and treatment oil and gas plants). Material selection for seawater handling systems. Guidelines for chemical treatments of pipelines. Protective coating and hot dip galvanising. Paint system approved. External coatings for corrosion protection of steel pipes and components. Internal coatings for corrosion protection of steel pipes and components. Internal coatings for corrosion protection. Maintenance of coated surfaces. Internal corrosion monitoring. Internal corrosion monitoring specification. functional requirements.

Eni S.p.A. Exploration & Production Division Ref. /18/ 27589.VAR.COR.PRG Ref. /19/ 02977.VAR.COR.SPC Ref. /20/ 20045.MAT.COR.FUN Ref. /21/ 20309.VAR.COR.PRG Ref. /22/ 20310.VAR.COR.PRG Ref. /23/ Ref. /24/ Ref. /25/ Ref. /26/ Ref. /27/ Ref. /28/ Ref. /29/

20557.VAR.COR.SDS 14039.VAR.COR.PRG 14059.PLI.COR.PRG 20384.PLI.MEC.SPC 20558.VAR.COR.SDS 20600. VAR.COR.PRG 14040.VAR.COR.PRG

Ref. /30/ 20311.VAR.COR.SDS Ref. /31/ 20415.SLI.OFF.SDS Ref. /32/ 07669.GPF.OFF.SPC Ref. /33/ 20181.STR.OFF.FUN Ref. /34/ 11558.VAR.COR.SPC

1.2.2

Guidelines for design and construction of cathodic protection systems. Cathodic protection planning of maintenance operations on cathodic protection plant components. Offshore platforms. Cathodic protection monitoring system. Cathodic protection of buried structures in plant facilities. Design and installation of systems to prevent alternating current induced corrosion. Corrosion risk assessment methodology. Corrosion survey guidelines. Inspections with intelligent pigs. Pipeline hydraulic testing. Workflow specification corrosion integrity management. Guidelines on corrosion and material selection normative. Corrosion control of vessels and pipelines during hydraulic tests, inactivity, shutdowns and cleaning operations. Cathodic protection underwater inspection. Guideline for sealine and riser inspection and maintenance program. Criteri di programmazione delle ispezioni periodiche su piattaforma offshore. Piattaforme offshore - Esecuzione delle Ispezioni. Protezione catodica. Misure e metodi di indagine per la verifica del grado di protezione di strutture interrate protette catodicamente.

ENI E&P Company Documents

Ref. /35/ ENI E&P Doc N° 1.3.0.08 Ref. /36/ Ref. /37/ Ref. /38/ Ref. /39/ Ref. /40/

1.3

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General Requirements for HSE Asset Integrity Management, Rev. 00, dated September 2009. SVI.TMS.MA.0001 TMS. Technology Management System Facilities Engineering Handbook. Rev- A02, 29/10/2004. SVI.DMS.GL.0003.000 DMS. Development Management System. Workflow Maps. Rev- A01, 22/02/2004. SVI.OMS.POS. MA.0001 Opportunity and Production Operation System Handbook. Rev- A02, 29/06/2005. 22010.MAN.GEN.SDS Operation & Maintenance Engineering. Guidelines for RCM Implementation. Rev. A01, 15/07/08. SVI.OMS.PMS.BP.0002.000 Operation Management System (OMS). Production Management System (PMS). Best Practice: Asset Integrity Review.

Acronyms and abbreviations

AIA

Asset Integrity Assurance

ALARP

As Low As Reasonably Practicable

BEDD

Basic Engineering Design Data

CMM

Corrosion Management Manual

CP

Cathodic Protection

CRA

Corrosion Resistant Alloy or Corrosion Risk Assessment

DMS

Development Management System

Eni S.p.A. Exploration & Production Division

EPC

Engineering, Procurement & Construction

FEED

Front End Engineering

Gp

OPOS Gate

HAZOP

Hazard and Operability Study

HSE

Health, Safety, Environment

IMP

Inspection and Maintenance Plan

KPI

Key Performance Indicator

LCC

Life Cycle Cost

MSFD

Material Selection Flow Diagram

NDT

Non Destructive Testing

O&M

Operation and Maintenance

OPDS

Opportunity and Project Development System

OPOS

Opportunity and Production Operation System

P&ID

Process Instrumentation Diagram

PED

Pressure Equipment Directive

PFD

Process Flow Diagram

RBI

Risk Based Inspection

TMS

Technology Management System

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Glossary and definitions

ALARP (As Low A concept of minimization that postulates that attributes (such as risk) can only be As Reasonably reduced to a certain minimum under current technology and with reasonable cost Practical) (Ref. API RP 580 Risk-Based Inspection). Asset

All physical facilities required for operations (Ref. /35/).

Audit

Systematic and independent control made to establish whether activities and results are consistent with planned activities and whether these are effectively carried out and suitable for reaching the goal (Ref. /38/).

Availability

The ability of an item to be in a state to eprform its function under given conditions at a given instant of time or over a given time interval, assuming that the required externalresources are provided. In other words the probability of fucntioning of a system or item at a given time; it also expresses the percentage of hours spent in the good status versus the ststem/item expected functioning (sum of the hours spent in good and failed status). Failed status considers both the no functioning due to failures and due to preventive maintenance. It is often defined as A(t) (Ref. /39/).

Availability Analysis

Prediction of the facility performance in terms of production availability. This takes into account both the facility reliability parameters and the maintainability parameters as result of the maintainability analysis.

Basic Design

The outline design providing the minimum necessary project specification to perform tender activities. The level of definition of the development concept achieved with Basic Design, can be further refined by carrying out FEED (Ref. /36/).

Consequence of The consequence of failure through the unintentional release of stored energy and failure hazardous material is the potential for harm. Duty Holders have a responsibility to assess the potential harm to the Health and Safety of employees and/or the public,

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and to the environment from pollution and other damage. They may also legitimately consider the consequences of failure on their business, such as the costs of lost production, repair and replacement of equipment and the damage to of the company reputation. Deliverable

Tangible, real output from an activity or process used in attaining the final goal of the project. Includes documents, data, plans, schedule, drawings, etc. (Ref. /36/).

Design Premises The Design Premises is a document establishing the company’s requirements in the detail necessary to enable the Engineering Team and/or an engineering contractor/consultant to prepare the project specification. It contains the constraints, in terms of available information, laws, codes, and the essential minimum standards and policies, which circumscribe the project and which would normally form part of the contract for preparation of a major project specifications. It is subject to update as further information is obtained (Ref. /36/). Failure

Termination of the ability of a system, structure, or component to perform its required function of containment of fluid (i.e. loss of containment). Failure may be unannounced and undetectable until the next inspection (unannounced failure), or may be announced and detected by any number of methods at the instance of occurrence (announced failure) (Ref. API RP 580 Risk-Based Inspection).

HAZOP (Hazard Qualitative methodology that identifies possible deviations from the correct and Operability functioning of the process and of the plant services, analysing moreover the Analysis) consequences of such anomalies and the actions to be taken to limit them to the smallest possible area (Ref. /38/). Inspection

Activities performed to verify that materials, fabrication, erection, examinations, testing, repairs, etc. conform to applicable Code, engineering, and/or owners written procedure requirements (Ref. API RP 581 Risk-Based Inspection Technology).

Risk

The combination of the probability of an event and its consequences. In some situations risk is the deviation from the expected. Risk is defined as the product of probability and consequences when probability and consequence are expressed numerically (Ref. API RP 581 Risk-Based Inspection Technology).

Risk Analysis

Use of all available information to identify the danger and evaluate the risk. The analysis can be both qualitative and quantitative (Ref. /38/).

Risk Management

The systematic process of identifying, analysing and responding to risk. It includes maximizing the probability and consequence of positive events and minimizing the probability and consequences of events adverse to planned objectives (Ref. /38/).

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2. INTRODUCTION 2.1

Asset integrity

Asset Integrity is defined as the Prevention of major accidents (Ref. /35/). A major accident is an unplanned event with escalation potential for multiple fatalities, serious damage to the environment or the asset, possibly beyond the asset itself, and/or to the reputation of the Company’ (Ref. /35/). A wider concept of asset Integrity is that defined in the “Operation Management System” (Ref. /38/, Section C.2.1.), where asset Integrity is defined as “an unimpaired state of fitness of an asset to operate for its specified, validated and verified designed purpose”. Asset Integrity Assurance (AIA) process encourages a value based management of the asset, so that production targets can be achieved without taking decision which may result in a long term loss of value. Hence a structured approach to Asset Integrity Assurance represents a necessary condition for ensuring the achievement of full value realization during production operations. Integrity of an oil and gas asset is the result of a multi-disciplinary approach, that necessitates giving due consideration to the performance of materials in the specific environments, the economics of the oil industry and local operations, the tolerable level of risk and the viable technological resources that may be deployed to reduce integrity-risk to acceptable levels. This requires an appropriate understanding of management, technical, operational and safety issues. During the lifecycle of an oil and gas asset, activities shall be carried out to ensure integrity be maintained from first evaluation through to decommissioning. For the success of integrity activities it is necessary that the integrity management system is designed, made-up and continuously revised and optimised during the full service life. Key integrity processes are required from the early design phase and have to be continued with endeavour for each of the stage of the asset lifecycle. Root causes for loss of asset integrity leading to failure of pressure containing systems and structural items may include: − inadequate design and/or material for the loading and operating environment; − incorrect and/or defective manufacture; − unanticipated in-service deterioration such as corrosion; − system errors in operation or maintenance or over-pressure protection; − malfunction of instrumentation, control systems or feed and utility supplies; − human factors; − external events such as fire, impacts, earthquakes or storms. An integrity management possibility of root causes analyses are examples of failure prevention when a manufactured condition.

strategy consists of measures to prevent, address and mitigate the of failure. Design reviews, quality assurance, training, and systems such measures. In-service inspection and monitoring are methods for root cause has led to deterioration from the design intent or the as-

With the term deterioration or degradation it is herein intended the onset or growth of damage or defects which can be: − macroscopic damage such as dents or gouges, bulging, deformation; − general or localised wall thinning and pitting; − material flaws, cracks, and welding defects; − degradation of material properties due to changes in the material microstructure. Deterioration can result from discrete events (e.g. welding flaws, impact damage) and the equipment may remain in that condition without further change. It commonly relates to age and service, initiating or becoming worse with time. To guarantee effectiveness, the periodical inspection must be sufficiently frequent in relation to the time between the deterioration becoming detectable and the onset of failure. Inspection techniques

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must be selected which are capable to detect the deterioration of concern with sufficient reliability at a sufficient early stage. 2.2

Corrosion

Corrosion of metallic materials, in particular of carbon and low alloy steels which still are the main construction material, represents the main issue for the integrity of the oil and gas production assets. Production facilities are exposed to external environment, as marine and industrial atmosphere, seawater or soil and are in contact with produced hydrocarbons. These are not corrosive by themselves, but corrosivity can be greatly enhanced by contaminants like carbon dioxide (CO2), hydrogen sulphide (H2S) and salty water. Actually, several corrosion mechanisms exist which can significantly affect the integrity and the durability of metallic materials. 2.3

Corrosion prevention and control

To face all corrosion mechanisms, the available consolidated knowledge shall be applied along the project life at the right time, at the right place and at the lowest costs. Knowledge for corrosion prevention and control is incorporated into a number of approaches, techniques and materials which, if correctly selected, designed and applied, allow to mitigate and control the corrosion mechanisms and thus guarantee the integrity of the components. The main techniques are: − corrosion allowance for carbon steel items; − use of corrosion resistant metallic materials; − use of plastics; − fluid treatment with chemicals, including: corrosion inhibitors, glycols, biocides, oxygen scavengers, H2S scavengers; − process intervention, including: phase separation, filtration, dehydration, deaeration, sweetening, stabilization; − cathodic protection; − organic coatings and linings; − metallic coatings (cladding or weld overlay).

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3. CORROSION INTEGRITY MANAGEMENT 3.1

Definition and targets

The Corrosion Integrity Management System is the general framework adopted by Eni E&P Division for managing and controlling the corrosion integrity of the assets. The primary purpose of the Corrosion Integrity Management System is to ensure that people involved in corrosion control in all phases of the project lifecycle have a clear understanding of what they are required to do, how they should do it and when they have to do it. The final targets of the Corrosion Integrity Management System are: − to assure the operability of the assets; − to guarantee the safety requirements of the assets; − to prevent any environmental issue. The activities to be performed within the Corrosion Integrity Management System make reference to OPDS (Opportunity and Project Development System) for the engineering phases and to the OPOS (Opportunity and Production Operation System) for the production phases. 3.2

Tasks

The Corrosion Integrity Management System consists and includes a number of main activities, hereinafter reported as tasks, through which the goals of the Corrosion Integrity Management System are pursued. The main tasks considered in this document are: − corrosion and corrosion prevention/control philosophies; − materials selection and corrosion prevention/control design; − corrosion monitoring and inspection design; − laboratory and field testing for qualification of materials and chemical treatments; − data management system; − corrosion management; − corrosion risk assessment; − risk-based inspections; − corrosion monitoring and inspections; − asset integrity review. 3.3

Tasks and the project lifecycle

The Corrosion Integrity Management System, through its own tools, is effective along all the lifecycle of the project, from Development to Operation. In this Document, reference is made to the following project phases (Ref. /37/, Ref. /38/): Development (OPDS): − evaluation; − concept selection; − concept definition; − execution; − commissioning, start-up and tests. Operation (OPOS): − handover to operation; − first period production; − running production and improvement; − running production and preparation to decommissioning.

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Figure 3.1 illustrates the positioning of the tasks of the Corrosion Integrity Management System with respect to the project phases.

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Exploration & Production Division

PROJECT PHASES TASKS

Evaluation

Concept Selection G1

Concept Definition

G2

Execution

Commissioning, Start-up, tests Handover to Operation

First Period Production

Running Product. & Improvement GP 1

1

Corrosion control philosophies

2

Materials and corrosion control design

3

Corrosion monitoring and inspection design

4

Laboratory and field testing

5

Data management

6

Corrosion management

7

Corrosion risk assessment

8

Risk-based inspections

9

Monitoring and Inspections

10

Asset Integrity review

Mandatory

Optional (or extensions)

Figure 3.1 – Corrosion Integrity Management tasks and project phases.

Preparation to Decommissioning

GP 2

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Tasks activities

In this paragraph the main Corrosion Integrity Management tasks are reviewed and for each task the minimum requirements are provided for: − task content; − input data and reference documents; − output and deliverables; − Company reference normative and supports. The following documents apply for document identification, facility codification and item numbering: − 27605.DOC.GEN.SDS Technical documentation required during the project development phase. − 20189.COO.GEN.SDS Technical document identification and title blocks. − 06215.DOC.GEN.SDS Facility functional units. − 20198.COO.GEN.SDS Item numbering.

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Exploration & Production Division

3.4.1

Corrosion control philosophy

This task is located in the very early stage of the project development. The aims are: − to identify the exposure conditions of the production facilities and to assess the severity of corrosion; − to provide viable options for corrosion mitigation. The task is mandatory for major projects and for new oil and gas fields located in harsh environments or in presence of high contents of contaminants, in particular H2S and CO2. The analysis shall include both external corrosion, affected by the natural environment, and internal corrosion, dominated by composition of the reservoir fluids. Typical issues for this analysis are: − review of atmospheric and soil corrosion conditions; − review of marine conditions (in case of offshore developments), including: meteo-marine data; sea water salinity; − main exposure conditions of the production facilities: atmospheric, submerged, splash zone, ice, etc.; − review of corrosive agents in the reservoir fluids, including: CO2, H2S, salts, mercury, elemental sulphur, etc.; − identification of the expected corrosion and degradation mechanisms; − categorization of the exposure conditions from corrosion viewpoint. Typical deliverables in this phase are: − Corrosion control and material philosophy. Depending on the project size, a unique study can be issued or more studies can be planned each covering homogeneous facilities, e.g. wells, pipelines, process units. This deliverable is intended as input for the definition of the corrosion control design task. Support normative includes the following ENI standards: − 02555.VAR.COR.PRG Design criteria. Internal corrosion. Corrosion parameters and classification of the fluid. − Any other applicable Company standard listed at Par. 1.2.1. Input data, output data, supports and contents of the task are illustrated in Figure 3.2.

Supports − − − −

Company standard International standard Software tools Corrosion data from fields in same geographical area

− Corrosion studies from similar fields Input & Reference Doc’s − Environmental conditions (atmosphere, soil, marine)

− − − −

Design premises (if available) Facilities Studies Reservoir data PVT studies

Corrosion Control Philosophy − Identification of exposure conditions − Expected external and internal

Output & Deliverables − Corrosion Control and Material Philosophy

corrosion mechanisms

− Produced fluid corrosivity preliminary assessment

− Selection of corrosion control techniques

Figure 3.2 – Corrosion control philosophy. Task description.

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Materials and corrosion control design

“Materials and corrosion control design” is the key task of the Corrosion Integrity Management System in the project development phase. If the activities from previous task have been performed (case of major projects), the relevant deliverables (Corrosion control and material philosophy studies) are adopted as input document; alternatively, the activities of the previous task are incorporated. The aims of this task are: − to assess the corrosion mechanisms and calculate the relevant corrosion rates, where applicable; − to select the most appropriate and cost effective materials; − to finalize the most appropriate and cost effective corrosion control techniques. Material selection is based on corrosion analysis and it covers the following main items: − metallic materials for well completion, pipelines, pipework, vessels, equipment and structures; − external coatings; − plastics, elastomers, linings. Material selection is strictly integrated with other corrosion prevention/control methods, namely: − corrosion allowance (for carbon and low alloy steels only); − fluid treatments with chemicals; − metallic cladding or weld overlay; − cathodic protection, including requirements for monitoring; − painting; − piping and pipeline external coatings; − process treatments. Typical deliverables are: − Corrosion Evaluation Studies; − Material Selection Reports and Material Selection Flow Diagrams (MSFD); − Fluid Treatment Reports; − Cathodic Protection Specifications and Drawings; − Painting Specifications; − Coating and Lining Specifications; − Documents covering special issues (if any). Support normative includes the following ENI standards: − 02555.VAR.COR.PRG Internal corrosion. Corrosion parameters and classification of the fluid. − 20603.MAT.COR.PRG Material selection and corrosion control for oil and gas process equipment. − 20019.MAT.COR.PRG Material selection for seawater handling systems. − 20312.VAR.COR.PRG Guidelines for chemical treatments of pipelines. − 20000.VAR.PAI.FUN Protective coating and hot dip galvanising. − 27591.VAR.PAI.SDS Paint system approved. − 20550.PIP.COR.FUN External coatings for corrosion protection of steel pipes and components. − 20551.PIP.COR.FUN Internal coatings for corrosion protection of steel pipes and components. − 20554.PIP.COR.FUN Internal coatings for corrosion protection. − 20552.VAR.PAI.FUN Maintenance of coated surfaces. − 27589.VAR.COR.PRG Guidelines for design and construction of cathodic protection systems. − 02977.VAR.COR.SPC Cathodic protection planning of maintenance operations on cathodic protection plant components. − 20045.MAT.COR.FUN Offshore platforms. Cathodic protection monitoring system.

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Exploration & Production Division − 20311.VAR.COR.SDS − 20309.VAR.COR.PRG − 20310.VAR.COR.PRG − 11558.VAR.COR.SPC − 20384.PLI.MEC.SPC − 08053.MAT.COR.PRG

Cathodic protection underwater inspection. Cathodic protection of buried structures in plant facilities. Design and installation of systems to prevent alternating current induced corrosion. Protezione catodica. Misure e metodi di indagine per la verifica del grado di protezione di strutture interrate protette catodicamente. Pipeline hydraulic testing. Materials and corrosion control methods in gathering and treatment oil and gas plants.

Input data, output data, supports and contents of the task are illustrated in Figure 3.3.

Supports − − − −

Company standard International standard Software tools Technical literature

Input & Reference Doc’s

Materials and Corrosion Control

− Corrosion Control and Material

− Corrosion mechanisms identification

Philosophy − Design Premises

− − − − −

Facilities Studies P&ID and PFD Material Balance Flow Dynamic Studies Process Studies

and corrosion rate assessment

− Material selection − Selection of corrosion control techniques (CP, coatings, etc.)

− Cost comparisons and value engineering

− Specification for corrosion control techniques

Output & Deliverables − − − − − − − −

Corrosion Evaluation Studies Material Selection Reports Material Select. Flow Diagrams Fluid Treatment Reports Cathodic Protection Spec. Painting Spec. Coating and Lining Spec. Special Issues

Figure 3.3 – Materials and corrosion control design. Task description.

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Corrosion monitoring and inspection design

This task is strictly integrated with the previous task ‘Materials and corrosion control design’ (Par. 3.4.2) and is intended to cover the aspects related to monitoring of internal corrosion, specifically of carbon and low alloy steel facilities. Design and planning of inspection activities, including intelligent pig inspections, aimed to assess the corrosion status, are also within the scope of the task. Design requirements for monitoring of cathodic protection systems, onshore and offshore, are usually part of the cathodic protection design package and are part of the previous task ‘Materials and corrosion control design’. Monitoring of internal corrosion is usually performed by means of permanent probes (Ref. /16/), but related requirements extend also to periodical chemical analysis, including residual concentration of corrosion inhibitor, bacteria counts, etc., as well as to inspections by NDT. The following main issues are part of the task activities: − safety aspects; − definition of corrosion monitoring and inspection philosophy; − selection of monitoring and inspection techniques and probes; − design of corrosion monitoring test points; − data acquisition concept (hard-wiring or manual); − procedures for probe retrieval or data collection; − criteria for data storing, analysis and integration with process data; − hardware and software requirements; − chemical analysis requirements. Typical deliverables of this task are: − Corrosion Monitoring Design Specifications; − Inspection Design Specifications; − Intelligent Pig Inspection Specifications. Support normative includes the following ENI standards: − 20555.VAR.COR.PRG Internal corrosion monitoring. − 20556.VAR.COR.FUN Internal corrosion monitoring specification. Functional requirements. − 14059.PLI.COR.PRG Inspections with intelligent pigs. Input data, output data, supports and contents of the task are illustrated in Figure 3.4.

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Exploration & Production Division Supports − Company standard − International standard

Input & Reference Doc’s − − − −

Corrosion Studies Material Selection Report Fluid Treatment Reports Hazard and operability studies (HAZOP)

Corr. Monit. & Inspec. Design − Monitoring and inspection philosophy − Selection of techniques, probes and locations

− Chemical analysis requirements − Safety related aspects

Output & Deliverables − Corrosion Monitoring and Inspection Design Specifications

− Intelligent Pig Inspection Specifications

Figure 3.4 – Corrosion monitoring design. Task description.

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Exploration & Production Division

3.4.4

Laboratory and field testing

Laboratory tests can be needed for: − qualification of candidate materials for service at specific exposure conditions; − selection and qualification of chemicals at conditions simulating the field ones. The first task is typically performed in case of materials, typically corrosion resistant alloys, whose performance at expected field exposure conditions needs confirmation. The second task is integral part of the procedure for the selection of chemicals, in particular corrosion inhibitors, where their use is going to be adopted. In both cases, reference is made as much as possible to existing international standards or protocols; however, specific test conditions shall often be considered. Laboratory test specifications are issued covering the requirements for test execution. Field tests should be also planned, in particular as final step in corrosion inhibitor selection among the products positively tested in laboratory. Typical deliverables of this task are: − Laboratory or Field Test Procedures Specifications; − Laboratory or Field Test Result Reports. Support normative includes the following ENI standard: − 20312.VAR.COR.PRG Guidelines for chemical treatments of pipelines. Several applicable standard are also available from the international normative. Input data, output data, supports and contents of the task are illustrated in Figure 3.5.

Supports − Company standard − International standard

Input & Reference Doc’s − Corrosion Studies − Material Selection Report − Fluid Treatment Reports − Product Datasheets

Laboratory and Field Tests − Laboratory tests of materials (metallic; elastomers; plastics) to confirm corrosion performance at field conditions − Laboratory tests for the screening of corrosion inhibitors − Field tests for the assessment of corrosion inhibitors efficiency performance

Output & Deliverables − Test Specifications − Test Results Reports

Figure 3.5 – Laboratory and field testing. Task description.

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Exploration & Production Division

3.4.5

Data management

The aim of the task is to gather, using convenient software tools, all information of significance for material performance and corrosion prevention and control. Activities of this task are initiated in the project development phase and are extended all over the project life through constant updating of the stored data. The aim is to give easy access to all information useful for corrosion management and asset integrity verification, in particular for performing corrosion risk assessment studies. Input data, output data, supports and contents of the task are illustrated in Figure 3.6.

Supports − Database and Software Programs (Inspection Manager)

−

Input & Reference Doc’s − − − − − − − −

P&ID and PFD, including as built MFD Item datasheets Operating data and KPI’s

Data Management − Software design and update − Data Loading

Output & Deliverables − On line access to loaded data − Data Reports − PED Analysis Report

NDT campaign results Corrosion monitoring results Fluid treatment data CP survey results

Figure 3.6 – Data management. Task description.

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Exploration & Production Division

3.4.6

Corrosion management

Corrosion management activities are typically gathered into the Corrosion Management Manual, which has to be issued in the development phase of a project and then maintained and updated during the operational phases. The Corrosion Management Manual is the document which identifies the key activities for corrosion control and the framework to mitigate and monitor corrosion mechanisms which may occur; it provides a reference document for field corrosion personnel, including all the necessary information to ensure an appropriate understanding and implementation of the corrosion management policy during the different phases of the project, and particularly operation. The Corrosion Management Manual outlines how the corrosion management process should be operated. It details roles and responsibilities, key performance indicators to help the corrosion management organization to define and measure progress toward goals, communication requirements and data acquisition and storage, in addition detailing with the corrosion threats and mitigation measures for each asset. Its objectives are: − to provide guidance to the operators regarding the corrosion threats affecting facilities; − to identify the consequences of inadequate control of corrosion to the integrity of facilities in order to recognise the importance of corrosion control methods; − to be a reference document for materials and corrosion engineers, responsible for the above issues, as a support to enforce adequate corrosion control and to demonstrate this task is accomplished; − to demonstrate to third parties that the potential risk of corrosion has been recognised and assessed, that adequate countermeasures have been enforced to cope with it, either in the design phase or during operations; − to provide background information for the development of an inspection programme, this includes routine and special inspections, corrosion coupon retrieving and data logging, chemical sampling for analyses etc. Input data, output data, supports and contents of the task are illustrated in Figure 3.7.

Supports − Company standard − International standard − Software Programs

Input & Reference Doc’s − Reservoir data − Fluid composition data − Material and Corrosion Design Documents

− P&ID; PFD; MFD − NDT campaign results − Corrosion monitoring results

Corrosion Management − Material and corrosion documents − − − − −

review Corrosion threats identification Corrosion management strategy Organization and personnel Inspection strategy KPI definition

Output & Deliverables − Corrosion Management Manual

Figure 3.7 – Corrosion management. Task description.

Eni S.p.A. Exploration & Production Division

3.4.7

20602.VAR.COR.SDS November 2009 Page 22 of 32

Corrosion risk assessment

Corrosion risk assessment is the key activity of corrosion integrity management. The task is aimed to identify, for given assets, the corrosion risk level of each item of the asset. The risk of a corrosion failure combines the probability of the failure to occur with a measure of the consequences of the failure. This definition envisages the main activities of the risk assessment studies, which are: − the assessment of the probability of a corrosion failure based on the identification of the corrosion damage mechanisms, the rate of progression of the damage and the tolerance of the item to damage, and − the assessment of the consequences in case of failure, including safety, environment and operability aspects. Different procedures can be adopted using different level of the analysis (qualitative, semiquantitative and quantitative). In all cases, for each item the probability of corrosion and the entity of the consequences are combined to give a corrosion risk ranking; the corrosion risk matrix represents the most used and effective tool. If the probability/consequence combination (risk) is high enough to be unacceptable, then a mitigation action for preventing the event is required. The following types of equipment and associated components are typically covered in corrosion risk assessment studies: − pressure vessels - all pressure containing components; − process piping - pipe and piping components; − storage tanks - atmospheric and pressurized; − boilers and heaters - pressurized components; − heat exchangers (shells, heads, channels and bundles); − pressure containing components of machinery (pumps, compressors). The corrosion risk assessment studies can be issued in the development phase of a project, as integral part of the corrosion management strategy, to verify the solutions adopted for corrosion mitigation. In the first period of the operational phase, when actual operating data become available a CRA (corrosion risk assessment) study is recommended. Then, the CRA study has to be periodical reviewed and updated using the most recent operating data and, when available, corrosion monitoring and inspection results. Support normative includes the following ENI standard: − 20557.VAR.COR.SDS Corrosion risk assessment methodology. Input data, output data, supports and contents of the task are illustrated in Figure 3.8.

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Exploration & Production Division

Supports − − − −

Input & Reference Doc’s − Reservoir data − Fluid composition data − Material and Corrosion Design − − − − −

Documents P&ID; PFD; MFD Operating data; Production profiles; NDT campaign results Corrosion monitoring results

International standard Company standard National regulations Software Programs

Corrosion Risk Assessment − Assessment of the probability of corrosion failure events − Assessment of the entity of the consequences − Corrosion risk matrixes

Output & Deliverables − Corrosion risk assessment studies

Figure 3.8 – Corrosion Risk Assessment. Task description.

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Exploration & Production Division

3.4.8

Risk-based Inspections

Risk Based Inspection (RBI) is a method for using risk as a basis for prioritising inspection efforts; it is strictly related to the corrosion risk assessment task, focussing on the risks associated with the failure of equipment due to degradation that could be detected before failure. Utilization of RBI provides a vehicle for continuously optimizing the inspection of facilities and systematically reducing the risk associated with pressure boundary failures. As new data (operating, inspection results, corrosion monitoring results, etc.) become available or when changes occur, a corrosion (re)assessment is needed and a revision of the RBI program shall be made appropriately. RBI offers the added advantage of identifying gaps or shortcomings in the effectiveness of commercially available inspection technologies and applications. In cases where technology cannot adequately and/or cost-effectively mitigate risks, other risk mitigation approaches can be implemented. RBI should serve to guide the direction of inspection technology development, and hopefully promote a faster and broader deployment of emerging inspection technologies as well as proven inspection technologies that may be available but are underutilized. Support normative includes the following ENI standard: − 20557.VAR.COR.SDS Corrosion risk assessment methodology. Input data, output data, supports and contents of the task are illustrated in Figure 3.9.

Supports − International standard − Software Programs

Input & Reference Doc’s − Corrosion risk matrixes − Corrosion risk assessment studies

− NDT specifications − NDT campaign results − Corrosion monitoring results

Risk Based Inspections − − − −

Review of CRA results Review of available NDT techniques Review of NDT and monitoring results Inspection plan definition

Output & Deliverables − Inspection Plans

Figure 3.9 –Risk Based Inspections. Task description.

Eni S.p.A. Exploration & Production Division

3.4.9

20602.VAR.COR.SDS November 2009 Page 25 of 32

Corrosion monitoring and inspections

This task includes: − all activities performed to monitor internal corrosion, directly or indirectly; − NDT inspections; − cathodic protection surveys, onshore and offshore; − site surveys; − failure analysis: performed in case of unexpected corrosion events occurrence. A number of inspections are planned in the ‘handover to operation’ phase, or at the very beginning of the operational period, with the aim to get an inspection baseline of items to be periodically inspected during operations. A typical example is the intelligent pig inspection of pipelines, run to obtain a picture of possible damages developed during the constructional phase and in the mean time to have a record to be used as reference for future inspections. Corrosion monitoring includes periodical measurements, probe retrieval, chemical analysis, etc., performed by a Company team of corrosion engineers or by service companies (typically the service company in charge for chemical treatments). Inspection activities are planned based on the results of Risk Assessment activities (Risk Based Inspections – see previous task), and they are managed in co-operation with the Maintenance Department. Typical deliverables for the corrosion monitoring and inspections task are: − Corrosion Monitoring Periodical Reports; − Chemical Analysis Bulletins; − Inspection Reports; − Cathodic Protection Reports. Support normative includes the following ENI standard: − 14059.PLI.COR.PRG Inspections with intelligent pigs. − 14039.VAR.COR.PRG Corrosion survey guidelines. − 02977.VAR.COR.SPC Cathodic protection planning of maintenance operations on cathodic protection plant components. − 20311.VAR.COR.SDS Cathodic protection underwater inspection. − 20415.SLI.OFF.SDS Guideline for sealine and riser inspection and maintenance program. − 07669.GPF.OFF.SPC Criteri di programmazione delle ispezioni periodiche su piattaforma offshore. − 20181.STR.OFF.FUN Piattaforme offshore - Esecuzione delle Ispezioni. − 11558.VAR.COR.SPC Protezione catodica. Misure e metodi di indagine per la verifica del grado di protezione di strutture interrate protette catodicamente. Input data, output data, supports and contents of the task are illustrated in Figure 3.10.

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Exploration & Production Division

Supports − International standard − Software Programs

Input & Reference Doc’s

Corr. Monitoring and Inspections

− Corrosion monitoring design

− Corrosion monitoring measurements − Chemical analysis − Cathodic protection surveys (onshore

documents

− Corrosion management manual − Inspection plans

and offshore)

− NDT campaigns − Intelligent pig inspections − Failure analysis

Output & Deliverables − Corrosion monitoring reports − Chemical analysis bulletins − Cathodic protection survey reports

− NDT inspection reports

Figure 3.10 – Corrosion monitoring and inspections. Task description.

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20602.VAR.COR.SDS November 2009 Page 27 of 32

Exploration & Production Division

3.4.10 Asset integrity review This task covers non-routine activities performed to assess the integrity status of oil and gas production facilities at given moments of the operational phase. Examples of situations which require asset integrity reviews are: − significant changes of the operations with respect to the original plans; − extension of the life of the asset; − acquisition of a new field and relevant assets. Detailed scope of work for asset integrity review shall be issued case by case depending on the specific needs of the task. Typically, it can include: − data acquisition and review; − verification of material compliance to normative; − execution of site surveys; − execution of corrosion studies; − identification of weak points and asset criticalities; − preparation of a Asset Integrity Improvement Plans (see also Ref. /40/). Asset integrity reviews can also be planned with aim to verify, for given assets, the performance of the adopted materials and corrosion control solutions and to generate ‘lessons learned’. Task deliverables are identified case by case, as well as input and reference documents. Input data, output data, supports and contents of the task are illustrated in Figure 3.11.

Supports − International standard − Software Programs

Input & Reference Doc’s − Material and corrosion control design package

− Corrosion management manual − Corrosion risk assessment studies and inspection plans

− Inspection reports

Asset Integrity Review − Past life data review − Site surveys − Material review and compliance verification

Output & Deliverables − Asset integrity reports − Corrosion studies and material verification reports

− Special issues studies − Lesson learned documents − Feedbacks to Company Standards

Figure 3.11 – Asset integrity review. Task description.

Eni S.p.A. Exploration & Production Division

3.5

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Main deliverables. Base requirements

The aim of this paragraph is to provide minimum requirements for the contents of the main deliverables issued as part of the Corrosion Integrity Management process. 3.5.1

Corrosion evaluation studies

The aim of this Document is to predict the expected mechanism of internal corrosion and to assess the relevant rates, when possible. The study shall be extended to all the main assets, including utilities. The following issues shall be covered: − reference normative; − all design data utilised for corrosion evaluation, including: fluid compositions; design and operating data; process description; materials under evaluation; − expected corrosion mechanisms; − assessment of sour service conditions (for fluids containing H2S only); − predicted corrosion rate intervals for weight loss corrosion mechanisms; − recommended corrosion prevention and control options; − cost comparisons (optional). 3.5.2

Material Selection Reports

The aim of this Document is to select convenient materials for the assets under study. The following issues shall be covered: − reference normative; − all design data utilised for material selection, including: project design life; fluid compositions; design and operating data; process description; materials under evaluation; − material selection philosophy; − recommended materials, including specific requirements: heat treatments; sour service requirements; surface treatments (internal); welding; internal cathodic protection; etc.; − corrosion allowance thickness (where applicable); − cost comparisons (optional). Material Selection Flow Diagrams (MSFD) are preferentially attached to the Material Selection Report; MSFD shall include: selected materials for main piping, vessels and equipment; corrosion allowance; chemicals injection points (if any); corrosion monitoring test points. 3.5.3

Cathodic Protection Specifications and Drawings

These documents shall cover the requirements for the cathodic protection of the assets under evaluation. The following issues shall be covered: − reference normative; − all design data utilised for CP system design, including: project design life; environmental conditions; structures drawings; structures materials; coating types and extent; − selection of CP type, if by galvanic anodes or by impressed current; − calculation notes; − monitoring systems; − minimum requirement for CP system components; − commissioning and operating procedure; − drawings (layouts; installation; details).

Eni S.p.A. Exploration & Production Division 3.5.4

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Corrosion Monitoring Design Specifications

These documents shall cover the requirements for monitoring of internal corrosion in gathering networks, process facilities and export pipelines. Minimum requirements for issue to be covered include: − HSE requirements; − corrosion monitoring philosophy; − applicable techniques; − permanent probes; − corrosion monitoring test points (to be shown on P&ID and MSFD); − data acquisition concept and requirements for instrumentation. 3.5.5

Corrosion risk assessment studies

Corrosion risk assessment (CRA) studies can cover all main type of assets, including: − Wells - production; water injection; gas injection; − gathering networks - piping in the wellhead area; flowlines; trunklines; − onshore treatment plants and storage tanks; − offshore topside facilities; − transfer pipelines, onshore or offshore; − offshore structures like: platform jackets; subsea wellheads; etc. The following issues shall be covered, as minimum requirements, by CRA studies (see also Ref. /23/): − reference normative; − facilities and item identification; − data collection and review; − corrosion analysis; − consequence analysis; − risk matrix; − results and recommendations.

Eni S.p.A. Exploration & Production Division

3.6

20602.VAR.COR.SDS November 2009 Page 30 of 32

The Corrosion Integrity Workflow

The tasks of the Corrosion Integrity Management are strongly interrelated, with the output of some tasks representing the input of other ones. This generates a workflow all along the project life cycle. The contents of each task and their complex relationships with the other tasks are obviously dependent on the project requirements and can vary case by case. However, some typical flows amongst the tasks can be identified. In particular, the tasks can be represented with respect to the main project parts, i.e. development and operation. In Figure 3.12 the workflow of the Corrosion Integrity Management tasks in the development phase of a project, from evaluation to start up, is illustrated. Figure 3.13 illustrates the task workflow in the operation period.

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20602.VAR.COR.SDS November 2009 Page 31 of 32

Exploration & Production Division TASKS

1

Corrosion control philosophies

Evaluation

Exposure Cond. Assessment

G1

Concept Selection

OPDS PHASES

G2

Concept Definition

Execution

G3

Hand over

Commissioning, Start-up & Performance Tests

Preliminary Corr. Report

Corrosion Prev. Philosophy

2

Material and corrosion control design

Design premises

Corrosion Analysis

Material Selection

Material Selection Report

Material Flow Diagrams

Reservoir data Fluid Treatments

Fluid Treatment Report

Corrosion Control Techniques

Coating and Painting Spc’s

PFD and P&ID

Process Documents Cathodic Protection Spc’s

Material balances

3

Laboratory and field testing

4

Corrosion monitoring design

5

Data management

Lab. Test Design

HAZOP

Corr. Monitoring Design

Laboratory Tests

Lab Test Evaluation Report

Field Tests

Corr. Monitoring Spc’s

Data Management

Asset Data Reports

The task continues in the operation phase

P&ID as-built

Monitoring data

Inspection data

Figure 3.12 – Corrosion integrity workflow. Development.

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Exploration & Production Division

TASKS

Execution

Concept Selection Commissioning, Start-up & Performance Tests Handover to Operations

6

Corrosion Management

First Period Production

GP1

Running Production and Improvement

Running Production & GP2 Prep. to Decommissioning

Material and Corrosion doc’s review Design Package (from development)

Personnel and Organization

Corrosion Management Manual

Risk Matrixes

CRA Study

Corr. Management strategy

to be updated (if needed)

from Data Management task

7

Corrosion Risk Assessment Assessment of Corrosion probabilities Data and Information

to be periodically updated

Assessment of the consequences

8

Risk Based Inspections

CRA results review NDT tecnical datasheets & spc’s

Inspection Plans to be periodically updated

NDT & monitoring results report review

feedback to Data Management task

9

Corrosion monitoring and Inspections

Intelligent pig inspections

Corrosion monitoring (permanent probes)

NDT

Cathodic protection survey & inspections

Failure analysis

Chemical analysis to be periodically repeated

10

Asset integrity review

from Data Management task from Material and Corrosion Control Design task

Data and Information Asset integrity review

Asset Integrty Reports

Feedback to Company Standard

Design Package

Figure 3.13 – Corrosion integrity workflow. Operation.

Reports