EPC Process Facilities Modification for Petroweld at EWT Bejil

Elixir Engineering was awarded to perform EPC Process Facilities Modification for Petroweld at EWT Bejil

Project Summary

COMPANY is established to perform exploration and development of petroleum hydrocarbons in the Kurdistan Region of Iraq with under PSC’s with the Kurdistan Regional Government in Block 11 (Harir-Bejil).“Harir-Bejil Block” is located within the administrative border of Aqra, Soran and Shaqlawa District, approximately 56 kilometers north-east of Erbil and 114km south-east of Duhok/Kurdistan Region of Iraq. The Block covers an area of 1472 km2.

Existing Facility Description:

• Bejil-1 Well Overview
• Location: Kurdistan
• Well: Bejil-1
• Purpose: Conduct an extended well test to determine oil pool size and develop a long-term production plan.
• Production: Sour oil, gas, and potentially water are produced
• Infrastructure
• Pipeline: Short pipeline from well to new separation facility.
• Manifold Skid (SK-900): Allows future wells to connect to the pipeline. Includes individual ESD valves controllable by the plant control system.
• Initial Separation Process
• Basket Strainer (ST-100A): Removes particulates from well production fluids.
• Slug Catcher (V-001): Separates produced gas, emulsion, and free water. Gas is directed to the HP flare knock-out drum (V-170) and then to the HP flare stack (FS-810). Free water is directed to produced water storage tank (TK-420).
• Emulsion Processing
• Basket Strainer (ST-100A): Removes particulates from well production fluids.
• Slug Catcher (V-001): Separates produced gas, emulsion, and free water. Gas is directed to the HP flare knock-out drum (V-170) and then to the HP flare stack (FS-810). Free water is directed to produced water storage tank (TK-420).
• Emulsion Processing
• Stage 1 Heat Exchanger (E-200): The emulsion from the Slug Catcher V-001 is then directed to the stage 1 heat exchanger (E- 200) where the mixture will be heated.
• Stage 1 Separator (V-100): Further removes vapours.Vapours directed to HP flare KO drum (V-170).Part of gas routed to storage tanks for blanketing.
• Stage 2 Heat Exchanger (E-210): Further heats remaining oil and water mixture.
• Gas Management
• Stage 2 Separator (V-110): Removes liberated gas. Gas directed to LP flare KO drum and then to LP flare stack (FS-800).Additional gas sourced from Stage 1 separator (V-100) if needed.
• Demulsification Process
• Demulsification Tank (TK-400): Allows oil and water to settle.Water migrates down, oil floats up.
• Backup Demulsification Tank (TK-401): Activated if TK-400 does not produce specification oil.
• Water Management: Clear water from TK-400 and TK-401 is pumped to water tank (TK-420).
• Oil Management: Clean oil from TK-400 or TK-401 is pumped to oil storage tank (TK-410). Oil is loaded into trucks through loading stations for transport.
• Gas Flare Systems
• Sour Gas Management: Sour gas from slug catcher (V-001) and Stage 1 separator (V-100) sent to HP flare system. Sour gas from Stage 2 separator (V-110) sent to LP flare system.
• Gas Equalization System (GES)
• Purpose: Equalizes pressure in gas spaces of various tanks to prevent oil losses from evaporation.
• Components: VRU blowcase (V-840) for outgoing gas streams.Tank vent blowcase (V-850) for gas supply lines.Liquid drainage from blowcase vessels using nitrogen under pressure.
• Vapour Recovery
• VRU: Captures high-concentration H2S vapours from tanks for compression and flare disposal.
• Truck Loading Operations
• Vent Gas Compressor (K-820 A/B): Collects gas vented during truck loading. Compresses and sends it to H2S scavenger vessel (V-820) for H2S removal.
• Blowcase Vessel (V-860): Collects liquids from loading arms, discharging to oil loading line.
• Support Systems
• Instrument Air System (IA-740): Supplies air via compressors and storage vessels.
• Nitrogen Generating System (NG-710): Produces 95% nitrogen stream for purging and backup gas supply.
• Heat Media System (FH-710): Heats emulsion and maintains tank temperatures.
• Power Supply
• Generators: Primary and secondary electric generators powered by diesel.
• Fuel Storage: Fuel stored in tank (TK-430), filtered, and pumped to heat media and generators.
• Waste Management
• Drainage: Plant drains flow to a slop tank.Slop tank contents processed through battery inlet when full.

Following facilities as per the Project scope are included in this HAZID study.

a) Replacement of the ТК-400/401/410/420 Gas Equalization System: Gas Equalization System (GES) is a system of piping designed to equalize the pressure in the gas spaces of De-Emulsification Tanks (TK-400/TK-401), Oil Storage Tank (TK-410) and Water Storage Tank (TK-420) during pump-out (inbreathing)/ pump-in (outbreathing) operation to avoid oil losses from evaporation.

The following modification scope for GES system are as follows:

• The existing GES piping will be replaced with new GES piping to equalize the pressure in the gas spaces of tanks to avoid oil losses during tank outbreathing scenario;
• New pipeline to supply gas from slug catcher V-001 to GES system;
• The existing Blowcase (V-840) will be replaced by Tank Vent Blowcase (V-850). One new Blowcase vessel, Tank Vent Blowcase (V-850) shall be provided along with new GES piping for the liquid fractions accumulation and draining from Gas Equalization System (GES);
• Nitrogen shall be provided as a motive fluid to transfer the liquids from blow cases to the slop tank.

b) Rearrangement of the VST ТК-400/401 Intra-site Piping and Pumping Stations

• New piping arrangement shall be provided at different locations of the plant for flexible operation of on-spec/ off-spec oil/ slop transfer to truck loading station/ process area. Refer mark-up PID for scope. It includes the following items.
• Gather off-spec oil from tanks TK-400, TK-401 transfer to the heater E-210 or 1st stage separator V-100 for re-processing;
• Gather on-spec oil from tank TK-400 & TK-401 and transfer to final product loading station;
• Reinforced concrete bund wall and Sun-roof for TK-430 Diesel Fuel Storage Tank;
• Pipe supports shall be provided in Gas Equalization Area and for tank interconnections, roof shelters, and drip pans in the loading gantry area;
• Diesel fuel pumps skid shall be relocated to a new installation site.

c) New Roof at Oil Filling-in (Loading) Stations C/D and Roof to close gap between existing roof for Station A/B and new roof for Station C/D

• New Roof shelters shall be provided at oil Filling (Loading) station area for Station C/D and roof shelter to close gap between existing roof for Station A/B.
• Roof shelter height, size and type shall be similar to existing roof shelter for Station A/B. Roof shelter shall be designed as per truck clearance envelope.
• Roof shelter structure and foundation shall be designed as per international standard.
• Drip pans shall be provided in perimeter of roof outline to segregate areas for storm water and potential contaminated drain water.
• Both roof shelters (Loading Stations A/B and C/D) shall be equipped by anti-bird diverters. Type and quantity of diverters shall be determined during design.
• New roof at Loading stations C/D shall be equipped by lightning protection. Coverage of lightning devices for all Loading area shall be recalculated, additional lightning protection devices to existing roof for Stations A/B shall be added in case of insufficient coverage of lightning protection for all Loading area.
• Provide stainless steel antipigeon spikes.
• Extend loading arms and access platform if required to provide access for loading as per envelope.
• Provide lightning for new roof of Stations C/D.

d) New reinforced concrete bund and new Sun-roof for existing TK-430 Diesel Fuel Storage Tank and relocation of existing diesel fuel pumps.

• Design, supply and construction reinforced concrete bund and Sun-roof for existing TK-430 Diesel Fuel Storage Tank.
• Relocation of existing diesel fuel pumps skid on new foundation with the provision of anchoring bolts should be arrange for the diesel fuel pump in a new installation site.
• Relocation of existing flood lights related to lighting of diesel pumps and diesel tank area shall be arranged in new installation site.

Trace heating of all diesel fuel pipe lines (to main and emergency generators and oil Heat Medium Skid) shall be developed and implemented.

Elixir Responsibilities

Elixir Engineering done different safety studies for EWT Bejil project. The safety studies conducted for this project scope is listed below:

Safety Studies

• HAZID
• HAZOP
• SIL

Hazard Identification (HAZID)

The overall intent of an HAZID study is to assist in demonstrating that the risk associated with all the identified hazards are managed and will be reduced to an acceptable level by:

• Checking the design and consider whether any external or internal cause, may generate a hazard to people working on the installation and/or to the general public, and/or a damage to the Assets and/or impacts to environment or reputation;
• Checking whether the precautions and safeguards incorporated in the Project are sufficient to either prevent the hazard occurring or mitigate the severity of any consequence to an acceptable level;
• Identifying and implementing additional precautions or safeguards to manage all the hazards not sufficiently incorporated during the design phase.
• HAZID is a structured review technique for the early identification of all significant hazards associated with the particular activity under consideration.
• HAZID is carried out by a systematic analysis of all the threats with the potential to generate health, safety, environmental, asset risks.
• Once the hazards have been identified, the associated risks are qualitatively assessed and risk prevention and mitigation measures identified in consistency with the adopted Risk Management strategy.

In this workshop, emphasis was on identifying any hazards introduced by activities related to the Project. However, attention was paid to the interactions between the existing facility and their impacts on the project.

HAZID methodology

• Many of the hazards and HSE issues are generic for the whole development and are not specific to any part of the plant or location.
• The procedure is firstly to apply the technique to the whole development as a single entity, as far as possible, and then review discrete areas as appropriate.
• The study method is a combination of identification, analysis and brainstorming based on the hazards identified with the help of a checklist of potential hazards.

The main topics covered by the checklist are

• External and Environmental Hazards
• Facility Hazards
• Health Hazards
• Project Implementation Hazards
• The HAZID review is conducted as a structured brainstorming session to identify potential hazard scenarios using appropriate guidewords.
• A comprehensive HAZID Checklist is used, though it is not exhaustive; brainstorming is encouraged to identify novel or unforeseen hazards.
• The HAZID Facilitator evaluates the system against the Checklist, examining each potential hazard and its associated threats (or causes).
• For each identified hazard, the specific threat and its consequences are determined. The adequacy and presence of existing safeguards (both preventive and mitigating) are assessed.The risk of each hazardous event is evaluated using a COMPANY Risk Matrix. Recommendations to reduce risks are identified during brainstorming, in line with the applied risk management process.

Hence, the following review process shall be facilitated

1. Identify a System on the general arrangement drawing;
2. Apply a guide word to identify a possible hazard;
3. Brainstorm and review the threats, causes and potential consequence of that hazard;
4. Identify the barriers, controls and/or mitigation measures currently in place;
5. Qualitatively assess the most severe receptor of hazards (i.e., people, environment, assets or reputation) and rate the severity, likelihood and risk (high, medium or low) associated with the hazard identified based on the COMPANY Risk Matrix;
6. Propose recommendation(s) and action party if further mitigation is required.
7. Steps (2) to (6) are repeated until all applicable guide-words have been exhausted and the team is satisfied that all significant deviations have been considered.

HAZID Basic Rules

The following ground rules are set before proceeding with the HAZID Session

• The team focuses on high level HSE risks associated with the Project;
• The HAZID results depend on team participation and maturity of data available;
• Prolonged & side discussion shall be avoided. The objective is to identify potential hazards not to design them out during the workshop; when disagreement arises, a recommendation will be issued
• Time will not be spent on finding solutions, unless solution is obvious;
• The likelihood of the hazards will be assessed by omitting the performance and effectiveness of existing controls;
• The worst-case consequence, as if no safeguards are in place will be recorded and ranked;
• Sections of the existing plant will not be considered in detail; only impacts to/ from the Project to these sections will be assessed.

Hazard & Operability Study (HAZOP)

Hazard and Operability (HAZOP) Study is a structured and systematic evaluation of a planned and/or existing operation to identify and evaluate potential hazards in design and operation.

• This study is carried out by a team of engineers from different disciplines.
• The team looks at each section of a plant or system or operation (node), considers potential deviations from intended operation and analyses their consequences against any existing safeguards. Impact of identified hazards on safety, asset and environment are assessed.
• HAZOP is a guideword driven brainstorming technique where the team members contribute based on their collective experience and lessons learnt from past projects.
• HAZOP study records the identified hazards without proposing any solution, unless a solution is obvious.
• Proposed solutions may include additional safeguards or operational procedures as necessary.
• The study record serves as a guide to determine the Health, Safety and Environment (HSE) issues to be resolved during the project.

Purpose of HAZOP

HAZOP for any project or modification serves many purposes including

• Identify the hazards inherent to the proposal.
• Identify the credible equipment instrument failure likely to lead to accident scenarios / hazards / operability problems
• In addition to these issues, HAZOP occasionally identified items which could improve unit operations and efficiency

HAZOP Methodology

The HAZOP focuses on the process / utility system and associated interfaces. The basic concept of a HAZOP study is to take full description of the process and question every part of it during brain storming meetings attended by the different specialists involved in the process design to discover firstly what deviations from the intention of design can occur and what their causes and consequences may be.

The main steps involved in a HAZOP study are as follows

1. Select the node (Line, equipment or a system) on the P&ID;
2. List of the intention & process parameters, guidewords for the nodes;
3. List all deviations an ignore deviations that are not meaningful and apply the deviation;
4. Brainstorm and list various causes of the deviation and ignore causes that are not credible;
5. Determine the consequences of the deviations due to each listed credible cause;
6. Identify safeguards already provided in the system
7. Suggest recommendations / actions, should the safeguards be inadequate;
8. Repeat steps 3 to 7 for each deviation
9. Repeat steps from one (1) to eight (8) on the next node until all the nodes are covered.

Elements of HAZOP Study

• Node definition — The HAZOP study progresses through the plant node by node. The selection of the node sizes and the route through the plant is made before the study by the facilitator. The node should be described in terms of: -
• Brief description of the node
• Typical operating and design conditions
• Method of operation and maintenance, and requirement for operator intervention
• Parameters — Flow, Pressure & temperature are usually regarded as the main parameters/elements. Additional parameters relate to general considerations like maintenance, safety, relief, corrosion/ erosion, instrumentation, start-up & shutdown, etc. Some of these may be selected for nodes in a study as appropriate based on relevance and concerns expressed by team members.
• Guidewords — Guide words are simple words or phrases used to qualify or quantify the intention and associated parameters in order to suggest deviations. Standard guide words; No/less, more/Less, As Well As/Part of, Reverse/Other Than, Early/Late, Before/After are applicable to each parameter. ‘Other Than’ is a very popular ‘catch all’ guide word at the end of each parameter
• Causes — All credible/ possible scenarios leading to the deviations should be considered when determining causes. The Causes should be “Local” to the node being studied. The consequences are deliberated only after listing all the Causes. Two events happening simultaneously without any correlation should not be considered.
• Consequence — “Global” effects should be considered for the consequences i.e., keep researching the resulting reactions till you reach the Ultimate Consequence of a deviation.
• Safeguards — Risk is a function of both Probability and Consequence. Safeguards reduce either Probability or Consequence. These could be either related to hardware or operator practices & intervention., While selecting safeguards, you may consider engineering or administrative safeguards, but it is necessary to check whether these are existing & functional for the operating plant.

Recommendations

Recommendations should be reported using action-based words (such as Check, Provide, Consider, Ensure, Review etc.), and assigned to specific work groups. It should be verified whether three chief questions have been explained, viz.

• What is to be done?
• Where is it to be done?
• Why is it to be done?

Safety Integrity Level (SIL)

• The SIL (LOPA) Study is undertaken on safety systems for the purpose of defining a SIL (Safety Integrity Level) rating for Safety Instrumented Functions (SIFs).
• The SIL rating of a SIF defines the integrity specification (and hence the minimum reliability requirement) and architectural requirements for SIF equipment.
• The SIL Classification process may be implemented to determine whether the existing or proposed design meets the integrity specification and if not, what changes are necessary to meet the integrity specification.

The following table provides the target performance requirement for each SIL as based on the definition in IEC 61511–1.

SILLow demand mode of operationRisk Reduction Factor (RRF)4≥1x10–5 to <1x10–410,000 to 100,0003≥1x10–5 to <1x10–41,000 to 10,0002≥1x10–5 to <1x10–4100 to 1,0001≥1x10–5 to <1x10–410 to 100

The following information and steps are required to perform the assessment of a given SIF

• Initiating cause(s): Identifying and listing all the causes leading to an impact event which requires SIF intervention (input from HAZOP study). Impact events can have several initiating causes and all of them shall be taken into account in the assessment;
• Impact event(s): Identifying and listing each impact event description (consequence) which requires SIF intervention (input from HAZOP study). The impact event can have one or more initiating causes;
• Severity level: Assessment of the level of the consequences of the impact event on the basis of the COMPANY Risk Matrix.
• Initiation likelihood: Assessment of the likelihood of each initiation cause previously listed (in events per year);
• Protection layers: All protection layers shall be listed (input from HAZOP). These consist in a grouping of equipment and/or administrative controls that function in concert with the other layers

Main part of the information described above is based on the HAZOP findings.

Following the steps illustrated in the figure above, the SIF’s required SIL can be determined by means of the next sequence:

1. Identify hazardous scenarios which can be created due to dangerous failure of each SIF;
2. Identify worst Consequence levels of hazardous scenario if SIF fails to operate on demand;
3. Categorise the consequence severity and find respective TMEL — Tolerable Maximum Event Likelihood (TMEL is individual for Safety, Environmental and Asset damage related consequences) as per Risk Tolerance Criteria. On the basis of the severity level of the impact event, the frequency of the impact event required to satisfy the tolerability requirements can be determined.

Consequence scaleTMELC1 Negligible10–2 [ev/y]C2 Minor10–3 [ev/y]C3 Moderate10–4 [ev/y]C4 Major10–5 [ev/y]C5 Extreme10–6 [ev/y]

1. List all causes and identify Initiating Event Frequency (IEF) for each cause. IEF is expressed in events per year.
2. Identify conditional modifiers, if any, and enabling events or conditions. Conditional modifiers are individual for each cause and also depend on consequence category (Safety, Environmental, Asset damage and Reputation). Please refer to section 6.2 for Conditional Modifiers.
3. Determine for each cause the Unmitigated Event Frequency (UEF).
4. For each cause, identify all available Independent Layers of Protection (IPL) and assign PFD for each IPL.
5. For each cause, calculate the Mitigated Event Frequency (MEF) by multiplying UEF with PFD values of all available IPLs. MEF = UEF*PA*PB*PC*PD where PA, PB, PC, PD are the PFD values for each IPL. Calculation of MEF to be done independently for Safety, Environment, Asset damage and Reputation related consequences.
6. Calculate the Total Mitigated Event Frequency due to all causes (Total MEF) which is the sum of MEFs for all causes. Total MEF = MEF (Cause1) + MEF(Cause2) + MEF(Cause3)

There shall be individual TMEFs for Safety consequence, Environmental consequence, Asset damage consequence and Reputation consequence.

1. Calculate required PFD and Risk Reduction Factor for each group of consequences (Safety, Environmental, Asset damage, Reputation).

PFD = TMEL / Total MEF

RRF = 1 / PFD

1. Assign the SIL based on PFD to close a gap between TMEL and Total MEF (“LOPA gap”). There will be individual PFD, RRF and SIL values for Safety, Environment, Asset damage and Reputation consequences.
2. Identify the highest one among three values of SIL — for Safety, Environmental, Asset damage and Reputation related consequences and record it as target SIL for the particular SIF.

In case of more than one cause or consequence, the highest RRF or SIL requirement shall apply for the respective SIF.

1. Required additional mitigations: In case the risk and/or the reliability required to the SIF is very high, recommendations and actions implementation may be issued. The implementation of these actions will be awarded to a specific Project part. These recommendations will be included into the dedicated Close Out Report.

SIL (LOPA) Main Parameters — The following sections show the main parameters to be assigned in each SIF Classification.

Initiating Events Likelihood Estimate

Initiation likelihoods for some typical failures are reported in the following table. Likelihood of more complex/specific initiating causes will be determined during sessions on the basis of the judgement and experience of the Team.

Conditional Modifiers

The following parameters can be used as conditional modifiers in LOPA scenarios wherever applicable. It may be noted that, to avoid double accounting, they should not be used as IPL if they are considered as conditional modifiers:

• Time at Risk (TAR). If the hazard is not present continuously due to intermittent operations, the Time at Risk factor (TAR) can be considered as a mitigating parameter;
• Exposure Time Parameter (EPT). Please note that this factor can be applied only if person presence is random with respect to hazard causes. For example, if hazard occurs only during start-up and operator is always present, this factor is equal to 1;
• Ignition Probability. The probabilities reported in the next table are suggested to be used as probability of ignition (Pi) for a given release;
• Enabling event is an action or condition which in combination with initiating event can result in the identified consequences. PFD of each event is same as that of the initiating event frequency as indicated shown in the previous table.

The following rules and values will be used when selecting and assessing the Conditional modifiers to be used for the LOPA.

IPL Identification

Independent Protection Layers are divided in the following groups:

• General process design: measures that reduce the likelihood of an impact event from occurring given the initiating cause occurrence (e.g., jacketed pipe or vessel);
• Basic Process Control System (BPCS): control loop that prevents the impacted event from occurring given the initiating cause occurrence;
• Alarms and operator action (only in case the operator may have the necessary time to provide the action following alarm activation);
• Consequence Mitigation Systems: mitigation layers are normally mechanical (e.g., pressure relief devices), structural (e.g. dikes) or procedural (e.g. restricted access). These layers do not prevent the occurrence of the impact event but can limit the severity. This category comprises:
• Mechanical devices;
• External Risk Reduction measures (Dyke etc.).
• Time at Risk factor (not applicable as IPL if used as conditional modifier);
• Ignition Probability (not applicable as IPL if used as enabling event or conditional modifier). Independent Protection Layers (IPL): These protections have a high degree of availability and shall comply the following four characteristics:
• Specificity: an independent protection layer shall be specifically designed to prevent the consequences of one potentially hazardous event;
• Independence: the operation of the protection layer shall be completely independent from all other protection layers; no common equipment can be shared with other protection layers;
• Dependability: the device shall be able to dependably prevent the consequence from occurring. Both systematic and random faults need to be considered in its design. The probability of failure of an independent protection layer shall be demonstrated to be less than 10%;
• Auditability: the device shall be proof tested and maintained. These audits of operation are necessary to ensure that the specified level of risk reduction is being achieved.

All the Protection Layers described above shall be characterised by their relevant Probability of Failure on Demand (PFD) in order to determine the risk reduction potential associated to each of them. The suggested values of Probability of Failure on Demand (PFD) to be used for the identified IPLs are summarised here below:

Risk Matrix

• COMPANY risk matrix will be used to qualitatively assess the consequence, likelihood and risk associated with the identified hazards.
• It shall be bear in mind that the method adopted will be capable of effectively classifying hazards, but without taking too much time or distracting the team from their primary focus.
• A five-category system will be used both for consequences likelihood and magnitude classification. In case of multiple consequences for the same deviation, the ‘worst case’ should be selected.
• Since the ranking exercise can be very time consuming, it is suggested that, in case of tight schedule due to prolonged discussion, only the worst risk ranking could be recorded among the consequence categories mentioned in the matrix.

Probabilities will be estimated according to the following scale, as per COMPANY’s Procedure:

Conclusion

The following steps were taken to ensure adherence to safety, operational, and environmental standards. The study benefits include enhanced process efficiency, improved safety, and optimized facility layout, enabling smoother operations. The project demonstrates Elixir Engineering’s capability in managing complex EPC projects with precision and a focus on quality outcomes.