HAZID HAZOP SIL TOR .docx

Project: CONSTRUCTION OF NEW PIPELINE FROM GUEBIBA TO CFTP HAZID/HAZOP/SIL/ TOR

HAZID/HAZOP/SIL TOR

CONSTRUCTION OF NEW PIPELINE FROM GUEBIBA/TB TO CFTP

001/AR03/13

03/12

HAZID/HAZOP/SIL TOR

PAGE: 2 /24

TABLE OF CONTENTS 1.

INTRODUCTION..........................................................................................3 1.1 ABBREVIATIONS............................................................................................................ 4 Compagnie Franco-Tunisienne des Pétroles.........................................................................4

2.

HAZID STUDY............................................................................................ 5 2.1 2.2 2.3

3.

HAZOP STUDY........................................................................................... 7 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10

4.

SCOPE & OBJECTIVES OF THE HAZID STUDY.........................................................................5 HAZID TECHNIQUE....................................................................................................... 5 HAZID RECORDING....................................................................................................... 6 SCOPE & OBJECTIVES OF THE HAZOP STUDY.....................................................................7 HAZOP METHODOLOGY................................................................................................. 7 HAZOP TECHNIQUE................................................................................................... 8 HAZOP RECORDING.................................................................................................... 11 HAZOP NODES......................................................................................................... 11 HAZOP TEAM........................................................................................................... 11 HAZOP FOLLOW UP................................................................................................... 11 HAZOP RECOMMENDATIONS......................................................................................12 PROCESS SYSTEMS / FACILITIES.......................................................................................12 REPORT.................................................................................................................. 12 SAFETY INTEGRITY LEVEL (SIL).....................................................................13

4.1 SCOPE & OBJECTIVES OF THE SIL STUDY........................................................................13 4.2 PROBABILITY OF FAILURE............................................................................................... 13 4.3 SIL CLASSIFICATION..................................................................................................... 14 1.1.1 RISK GRAPH TECHNIQUE...........................................................................................14 1.1.2 LAYER OF PROTECTION ANALYSIS..................................................................................15 4.4 RISK MATRIX.............................................................................................................. 15 4.5 RISK REDUCTION........................................................................................................ 16 4.6 RISK ANALYSIS TEAM.................................................................................................... 16 4.7 SIL RECORDING......................................................................................................... 17 5.

APPENDICES............................................................................................ 18 5.1 PROCESS SAFETY RISK GRAPH......................................................................................... 18 5.2 COMMERCIAL RISK GRAPH............................................................................................. 20 5.3 ENVIRONMENTAL RISK GRAPH......................................................................................... 21 5.4 TYPICAL PROBABILITIES OF FAILURE ON DEMAND (PFODS) FOR MENTIONED TYPES OF INDEPENDENT PROTECTION LAYERS (IPLS)............................................................................23

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 3 / 24

1. INTRODUCTION This document provides significant aspects and considerations of HAZID, HAZOP, and SIL study related to the construction of new pipeline from guebiba/tb to cftp project.

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 4 / 24

2. Abbreviations The following abbreviations will be used: CFTP

:

Compagnie Franco-Tunisienne des Pétroles

HAZID

:

Hazard Identification

HAZOP

:

Hazard & Operability

SIL

:

Safety Integrity Level

SIF

:

Safety Instrumented Function

P&ID

:

Piping & Instrumentation Diagrams

SLC

:

Safety Life Cycle

LOPA

:

Layer of Protection Analysis

CIL

:

Commercial Integrity Levels

E/E/PES

Electrical/electronical/programmable electronical systems

IPF

:

Instrumented Protective Function

IEC

:

International Electrotechnical Commission

EIL

:

Environmental Integrity Levels

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 5 / 24

3. HAZID Study 3.1 SCOPE & OBJECTIVES OF THE HAZID STUDY For this project, HAZID (Hazard Identification) analysis is required: the overall objective is to produce a facility in respect of which all risks to the human, Environment, company reputation and the assets have to be identified and minimized. The HAZID worksheet objectives are: 

To systematically analyse the Project for potential hazards identification.



To list all the needed documents about the project, that must be prepared in the following basic or detail design phase.



Considering the simplicity of the design, the risk-ranking for the recommendations has been limited to cases where a clear critical consequence was specified and the recommendation is proposed as a choice between different solutions.



For all the recommendations requiring further analysis, design and / or engineering studies / documents, operating procedures development, or other efforts that however must be done or prepared, the risk ranking will be considered superfluous. 3.2 HAZID TECHNIQUE

The HAZID Review will be conducted as a guided brainstorming, by means of guidewords applied to the project. The specific intention of this Hazards review is to highlight and estimate hazards deriving from the new pipeline from Guebiba/TB to CFTP, not only at normal operation phase but also during construction, commissioning and maintenance activities. The analysis is concentrated on the inherent external and internal hazards for the project, and is focussed on specific parts of the selected process, philosophies and operational concepts. A part is dedicated to the environmental aspect where potential impacts, corresponding causes, consequences and associated protections are identified, this analysis enables quick and yet trustful setting of documented Environmental Protection and regulatory compliance measures. With the help of guidewords, hazards will be identified together with potential means of control and mitigation. For each hazard, a qualitative assessment of the expected likelihood and severity of consequences will be given, on the basis of the risk assessment documents. The minutes of the HAZID Review detailing the hazards, causes and consequences, risk-ranking, recommendations and residual risk ranking will be recorded in HAZID Worksheets.

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 6 / 24

Figure 1: HAZID PROCEDURE 3.3 HAZID RECORDING The discussion will be recorded by the HAZID Secretary using dedicated software: “LEADER 2015 version”.

NO. REV. 0 PAGE: 7 / 24

HAZOP/HAZID/SIL/SIMOPS ToR

4. HAZOP Study 4.1 SCOPE & OBJECTIVES

OF

THE HAZOP STUDY

HAZOP (Hazard and Operability Study) is a qualitative methodology that identifies possible deviations from the correct functioning of the process, analyzing moreover the consequences of such anomalies and the actions to be taken in order to limit them to the smallest possible areas. The HAZOP’s targets are: -

To identify possible deviations from the intended operation that can cause personnel or

-

equipment harm as well as operation disturbances (accidental events), To establish how deviations from the design intent can arise, To assess whether such deviations and their consequences can have a negative effect upon

-

the safe and efficient operation of the system, To recommend actions, whenever is necessary, in order to remedy to the deviations.

4.2 HAZOP METHODOLOGY The method used for the HAZOP is a systematic review of the process; therefore the primary words will be the process parameters: Flow, Pressure, Temperature, Composition, and Level. And the secondary words, which are combined with a primary keyword, are the different HAZOP guidewords permit to suggest possible deviations: No, Less, More, Part of, As well as, Reverse, Other than…etc. In practice, the process parameters are combined with standard guidewords to set down a list of deviations from the normal operation of the system under review. The following combinations were used in this Study: Table 1: Deviations represented by Parameters and Guidewords Parameters

Guidewords

Flow

No Reverse More Less

Temperature

More Less

Pressure Composition

Level

More Less As well as Part of

More Less

Deviations No Flow (complete lack of flow) Reverse Flow (flow in the opposite direction than the normal operation) More Flow (higher flow rate than expected) Less Flow (lower flow rate than expected) Higher Temperature (than expected) Lower Temperature (than expected) Higher Pressure (than expected) Lower Pressure (than expected) Contamination Composition Change (fluid composition different than expected, e.g. offspec feed, incorrect chemical dosing, etc.) Higher Level (higher liquid level in a vessel or tank, up to overfilling condition) Lower Level (lower liquid level in a vessel or tank, up to a complete loss of level)

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 8 / 24

Parameters

Guidewords

Deviations

Other

Other

Other (any other cause of upset or unsafe condition identified during the HAZOP but not linked to an identified parameter)

4.3 HAZOP TECHNIQUE HAZOP is a systematic procedure used to review the process design for identification of potential hazards and operability problems caused by deviation from the design intent of both new and existing process facilities. The methodological approach is to identify deviations from the design intent using parameters and appropriate guidewords, and to define any actions necessary to reduce the probability of occurrence and/or eliminate/mitigate the consequences. The system will be divided into discrete Nodes (a "node" is a sub-system or a portion of a systems which can be analyzed alone, e.g. a tank, a header, a pump, even a single line, together with the relevant connections to the interfaces), and the methodology will be applied thoroughly to each node until all the system be fully analyzed. The method involves the following steps for each Node: 

Define a Node of the process on the P&IDs;



Clarify the design intent and the normal operating conditions of the Node;



Identify a Deviation from the intent or operating conditions by applying parameter and a Guidewords;



List possible Causes and Consequences of the Deviation (a Deviation can be considered “meaningful” if it has credible causes and can result in harmful consequences);



Identify the Safeguards (if any), as shown in project documentation;



Formulate Recommendations (and identify the responsible for implementation/action) if no sufficient Safeguards are provided.

HAZOP/HAZID/SIL/SIMOPS ToR

NO. REV. 0 PAGE: 9 / 24

The following figure summarizes the HAZOP Procedure that has been applied.

Figure 2: HAZOP PROCEDURE If a deviation and/or event are found to be realistically possible and to give rise to a significant consequence, it is discussed in the HAZOP Study Worksheets. The cases where there are no credible causes of deviation, and/or no events giving rise to significant consequences, will not been recorded on the Worksheets. The keyword combinations will be discussed following an iterative process in order to identify potential problems, as the diagram mentioned below:

NO. REV. 0 PAGE: 10 / 24

HAZOP/HAZID/SIL/SIMOPS ToR

Describe process section

Select a Node and describe design intent

Have all relevant Parameter for this plant section been considered?

Yes

No

Select a parameter not previously considered (e.g. Pressure)

Have all relevant guideword for this parameter been considered?

Yes

No

Select a guideword previously considered (e.g. More)

Determine cause of deviation from design intent; assess potential hazard/operational problem associated with the defined cause

Are there any causes for this deviation not previously discussed and recorded?

Yes

Record the new cause

No

Are associated consequences of any significance?

Yes

Record the consequence/s

Record any Safeguards identified

No

Having regard to the consequences and Safeguards, is an Action necessary?

Yes

Record the agree Action

No

HAZOP/HAZID/SIL/SIMOPS ToR

NO. Rev. 0 PAGE: 11 /24

4.4 HAZOP RECORDING The HAZOP discussion will be recorded by the HAZOP Secretary using dedicated software: “LEADER – 2015 VERSION”. This software leads to: -

A complete sets of topics added instantly; A vast Leader Library, puts hundreds of standard HAZOP deviations; Add own custom topics to any section, to the library, or to the project template that can be

-

created; Copy, reorder, and renumber topics.

The record will be made during the session using laptop, and will be projected onto a suitable screen so that all team members can see inputs to the record as it is produced. 4.5 HAZOP NODES In order to perform the analysis and focus the team’s attention on a specific area, the different process systems will be divided into a convenient number of discrete nodes. Each node represents a section of the system that can be composed by one or more items with homogeneous characteristics in terms of pressure, temperature or service. A new node starts when main process parameters change or isolation is present. 4.6 HAZOP TEAM The HAZOP shall be carried out by a multidisciplinary team to ensure all aspects of the plant and its operations are covered. The team member’s specialists include process design, instrumentation and control, mechanical engineering, safety and operation. The chairman has to: 

Select the team’s members



Plan and prepare the study,



Chair the HAZOP meetings: Trigger the discussion using guidewords and parameters,



Follow up progress, Ensure completeness of the analysis.

The team will include a nominated scribe, responsible for recording discussion and findings. 4.7 HAZOP FOLLOW UP The HAZOP Actions Coordinator will be responsible for ensuring the Action Items are forwarded to the parties responsible for action implementation, and for recording the status of the actions. The relevant discipline specialists should close-out the addressed actions, indicating the resolution and providing references and evidence of implementation. The action sheet completed with close-out

HAZOP/HAZID/SIL/SIMOPS ToR

NO. Rev. 0 PAGE: 12 /24

information shall be returned to the HAZOP Actions Coordinator. The HAZOP Actions Coordinator should review the responses and proceed until full resolution of all pending issues. When an action is closed, the HAZOP Actions Coordinator should mark the action as “CLOSED” in the action status column. When all actions will be closed, the Coordinator can issue the close-out report (i.e. the collection of all the resolutions and action close-outs). All Actions shall be ideally closed before the end of the Engineering Phase. 4.8 HAZOP RECOMMENDATIONS The analysis results of the HAZOP study shall be represented by a series of recommendations which take the form of suggested design changes, requirements of verification and additional studies or suggestions for specific operational procedures to be implemented. The recommendations will be managed in the activity of follow-up and implemented during the project development. 4.9 PROCESS SYSTEMS / FACILITIES To ensure process integrity and to identify process hazards and operational problems for process systems or facilities, a systematic review of the P&IDs shall be made. 4.10

REPORT

The HAZOP Report is a key document pertaining to the safety of the plant. It should provide sufficient information on each element so that, either read alone or together with available and clearly cross referenced documents, an assessment can be made of the adequacy of the HAZOP study carried out. The contents of such a summary might typically be: -

Introduction;

-

System definition and delimitation;

-

Documents (on which the analysis is based);

-

Methodology;

-

Team members;

-

HAZOP results:



Reporting principles,



Classification of recordings,



Main results;



HAZOP study worksheet.



Appendices: P&IDs (marked),

HAZOP/HAZID/SIL/SIMOPS ToR



List of participants.

NO. Rev. 0 PAGE: 13 /24

NO. Rev. 0 PAGE: 14 /24

HAZOP/HAZID/SIL/SIMOPS ToR

5. Safety Integrity Level (SIL) 5.1 SCOPE & OBJECTIVES OF THE SIL STUDY The analysis of hazards and risks gives rise to the need to reduce the risk and within the SLC of the standards this is identified as the derivation of the safety requirements. There may be some overall methods and mechanisms described in the safety requirements but also these requirements are then broken down into specific safety functions to achieve a defined task. In parallel with this allocation of the overall safety requirements to specific safety functions, a measure of the dependability or integrity of those safety functions is required. What is the confidence that the safety function will perform when called upon? This measure is the SIL. More precisely, the safety integrity of a system can be defined as: "The probability (likelihood) of a safety-related system performing the required safety functions under all the stated conditions within a stated period of time." Thus the specification of the safety function includes both the actions to be taken in response to the existence of particular conditions and also the time for that response to take place. The SIL is a measure of the reliability of the safety function performing to specification. 5.2 PROBABILITY

OF FAILURE

To categorise the safety integrity of a safety function the probability of failure is considered – in effect the inverse of the SIL definition, looking at failure to perform rather than success. It is easier to identify and quantify possible conditions and causes leading to failure of a safety function than to guarantee the desired action of a safety function when called upon. Two classes of SIL are identified, depending on the service provided by the safety function 

For safety functions that are activated when required (on demand mode) the probability of



failure to perform correctly is given, whilst For safety functions that are in place continuously the probability of a dangerous failure is expressed in terms of a given period of time (per hour) (continuous mode).

The probabilities of failure are related to one of four safety integrity levels, as shown in Table 1: Table 2: Probability of failure

Probability of failure Safety Integrity Level (SIL) b 4 3 2 1 a

Mode of operation – on demand (average probability of failure to perform its design function upon demand)

Mode of operation – continuous (probability of dangerous failure per hour)

A single E/E/PES is not sufficient ≥ 10-5 to < 10-4 ≥ 10-9 ≥ 10-4 to < 10-3 ≥ 10-8 ≥ 10-3 to < 10-2 ≥ 10-7 ≥ 10-2 to < 10-1 ≥ 10-6 No special safety requirements

to to to to

< < < <

10-8 10-7 10-6 10-5

HAZOP/HAZID/SIL/SIMOPS ToR

NO. Rev. 0 PAGE: 15 /24

5.3 SIL CLASSIFICATION The following methods will be used for Target Safety Integrity:  Risk Graph  Layer of Protection Analysis (LOPA) Both these methods are included in the IEC61508 and IEC61511 standard. The risk graph is a qualitative technique, the results tend to be quite subjective and lead to SIL levels biased on the high side. The Layers of protection analysis technique is quantitative and more accurate and it is becoming the widely accepted technique for SIL determination. 5.3.1

RISK GRAPH TECHNIQUE

The risk graph method is a qualitative approach to determine the level of integrity required for the identified Instrumented Protective Functions (IPF) for the project. The approach is based on the International Electro technical Commission standard, IEC61511. Risk graph analysis uses four parameters to make a SIL selection. These parameters are consequence (C), occupancy (F), probability of avoiding the hazard (P), and demand rate (W). -

Process Safety Risk Analysis

Each loop shall be reviewed on the following basis: 

Consequence Severity



Personnel Exposure



Alternatives to Avoid Danger



Demand Rate

The SIL rating is calculated using the response to the 4 questions and the appropriate SIL level is generated using the IEC risk graph attached in Appendix (6.1). -

Commercial Risk Analysis

Each of the loops reviewed shall be subjected to an Asset Protection Review. This shall be carried out on the following basis: 

Consequence Severity



Demand Rate

The risk graph for asset / economic loss is provided in Appendix. Before this chart is used, it must be calibrated for the specific plant it is used on. Consequence severity should represent the meaningful range of negative impacts towards important asset or economic objectives (e.g. reliability, replacement or repair costs)

HAZOP/HAZID/SIL/SIMOPS ToR

NO. Rev. 0 PAGE: 16 /24

The equivalent CIL rating is calculated using the response to the 2 questions and the appropriate equivalent CIL level is generated using the IEC risk graph attached in Appendix (6.2). -

Environmental Risk Analysis

Each of the loops reviewed shall be subjected to an Environmental Review. This shall be carried out on the following basis: 

Consequence Severity



Demand Rate

Environmental protective functions should be assessed against a risk graph that provides the range of negative consequences with respect to important environmental objectives for the specific plant, area of operation and local legislative requirements. For example, violation of discharge permits or flare consents spills of varying magnitude. The equivalent EIL rating is calculated using the response to the 2 questions and the appropriate equivalent EIL level is generated using the IEC risk graph attached in Appendix (6.3). 5.3.2

LAYER

OF

PROTECTION ANALYSIS

LOPA is one of the techniques developed in response to a requirement within the process industry to be able to assess the adequacy of the layers of protection provided for an activity. Initially this was driven by industry codes of practice or guidance and latterly by the development of international standards such as IEC61508 and IEC61511. Once the tolerable frequency for a SIF is established, all causes of the initiating event are listed. For each cause of the initiating event, its likelihood is established. The layers of protection and associated PFD for each cause are then listed. The mitigated event frequency for each cause is determined. After each cause is analyzed the total event frequency due to all causes for the initiating event is determined. The SIL is determined by comparing the established tolerable frequency (goal) with the total mitigated event frequency. 5.4

RISK MATRIX

The risk matrix is a method categorizing the frequency or likelihood and severity of a risk event using multiple qualitative levels. The risk matrix tolerance will represented with risk matrix. The OMV risk matrix is shown below:

Frequency (Cases Per Year) E Frequent (> 1*10^-2/year) D Probable (1*10^-2 to 1*10^-4/year) C Seldom (1*10^-4 to 1*10^-5/year)

Intolerable Region Tolerable if ALARP Region

NO. Rev. 0 PAGE: 17 /24

HAZOP/HAZID/SIL/SIMOPS ToR

B A

Unlikely (1*10^-5 to) Improbable (