iFluids Engineering and Consultancy WLL was awarded to perform HAZOP study for FEED various facilities of Qatar Gas, including :
- HAZOP Study – FEED for Barzan Gas Plant supply pipelines, Qatar Gas.
- HAZOP Study – FEED for Wastewater Treatment Plant of Qatar Gas
- HAZOP study – FEED – Laffan Refinery 2 capacity enhancement to 110% for Qatar Gas.
What is HAZOP?
Hazard and Operability (HAZOP) Study is a systematic and structured evaluation conducted on an existing or proposed operation. Its primary goal is to identify and evaluate potential hazards at various stages of a process, from design to operation. To know more on HAZOP Study Click Here
Case Study 1 – HAZOP Study – FEED for Barzan Gas Plant supply pipelines, Qatar Gas
Qatar Gas is planning to establish a new Liquefied Petroleum Gas (LPG) Bottling Plant, which involves three packages, with a particular focus on Package 1.
Within Package 1, propane and butane will be sourced from Barzan Gas Plant and Pearl GTL facilities. These gases will be metered at a new blending station situated on a plot currently located within Barzan Gas Plant, adjacent to QP Station A4. The blended LPG will then be transferred through a pipeline to the new LPG bottling plant, where it will also undergo metering.
Qatar Gas’s scope of work within Barzan Gas Plant (ISBL) to support Package-1 includes:
- Tying into or taking off from the existing common run-down headers within Barzan.
- Installing new piping, routing it through the pipe rack, and terminating it 1m outside the Barzan plant fence. This will involve the incorporation of appropriate positive isolation valves to enable QP to perform the tie-in as part of their OSBL scope.
The objective of this project is to conduct a HAZOP study aimed at enhancing the resilience of the supply pipelines in the event of a failure in the existing facility.
Case Study 2 – HAZOP Study FEED for Wastewater Treatment Plant of Qatar Gas
QG1 is a fully integrated facility consisting of three (3) LNG process trains that collectively produce approximately 10 million tons per annum of LNG. The wastewater generated by QG1 is presently treated through an MBR unit at the existing QG1 WWTP and subsequently reused for irrigation. Additionally, QG1 has commissioned new AGR and SRU units as part of the PMP.
At present, certain high COD wastewater streams from the PMP are directed for biological treatment at the QG1 WWTP, while other streams (such as chemical effluent, stripped sour water, and boiler blow-down) are neutralized within the PMP’s battery limits and reused for irrigation. Stormwater is collected and discharged into the sea through the existing QG1 cooling water outfall channel.
The objective of the project is to conduct a comprehensive HAZOP study and develop FEED (Front End Engineering Design) work for the proposed facilities, incorporating modifications to the original FEED already performed. This includes associated systems and the development of the Engineering, Procurement, and Construction (EPC) package for further progression into the EPC phase. The QGWP’s aim is to reuse and recycle treated wastewater streams from both QG1 and PMP in compliance with environmental regulations set by the MME.
Case Study 3 – HAZOP study FEED for Laffan Refinery 2 capacity enhancement to 110% for Qatar Gas.
Qatar Gas, aimed to perform a FEED study for Debottlenecking LR2 Facilities to achieve 110% of the current design capacity with minimal modifications while maintaining the current condensate quality. The study also encompassed an evaluation of the EPC Scope of work and an adequacy check for the Amine Regeneration Unit to accommodate 110% of LR2 capacity. The primary goal of this study was to assess the potential hazards and their impacts on health, safety, the environment, and the company’s reputation.
Condensate Fractionation Unit 12 is designed to separate condensate into the following components:
- Overhead LPG and Naphtha intermediate, which undergoes further processing in the Naphtha Hydrotreater Unit 15 (NHT) and then in the Saturation Gas Plant Unit 13.
- Straight run Kerojet intermediate, which is further processed in the Kerosene Hydrotreating Unit 16 (KHT).
- Light Gas Oil intermediate, sent to Diesel Hydrotreating Unit 29 (DHT).
- Heavy Gas Oil product, which is sent to Qatar Gas 3/4.
- Another Heavy Gas Oil product, sent to LR1 rundown system.
As the condensate has progressively become lighter, resulting in increased naphtha production at U12, and LR1 Unit 12 is already operating at 110% of its capacity, there is a need to enhance LR2 production to reach 110% of its current U12 operating capacity with minimal or no hardware modifications.
This scenario considers the operating capacity as 110%. The Amine Generation Unit’s adequacy for 110% of LR2 capacity will also be evaluated through a techno-economic assessment.
HAZOP Methodology
The Hazard and Operability (HAZOP) Study is a methodical and organized assessment of a proposed or current operation, aimed at detecting and assessing potential hazards in both the design and operation phases. This study is conducted by a group of engineers with diverse expertise.
The team conducts a comprehensive examination of individual segments of a plant, system, or operation, commonly referred to as nodes. They evaluate the likelihood of any deviations from the intended operation and assess their potential consequences in light of any existing safeguards.
The assessment of the impact of identified hazards on safety, assets, and the environment is conducted. The HAZOP methodology is a brainstorming technique that is driven by the use of guidewords. The team members make contributions based on their combined experience and knowledge gained from previous projects.
The HAZOP analysis procedure documents the hazards that have been identified, refraining from suggesting any solutions unless a clear solution presents itself. Potential resolutions could comprise supplementary measures or functional protocols as deemed essential. The study record functions as a tool for identifying the Health, Safety, and Environment (HSE) concerns that require resolution throughout the project.
The objectives of the HAZOP study are:
- The task at hand involves the identification and assessment of potential hazards and risks that may be linked to process facilities.
- Identify operability and maintenance issues
- Comprehend these perils/challenges and assess their probable outcomes.
- Propose supplementary measures or protocols as deemed essential.
These steps will lead to a better design/ operation of the facility to mitigate the potential hazards identified.
Following are the Facility documents required for Conducting HAZOP study:
- Project and Facility Description
- Facility Layout Drawings
- Process Flow Diagrams
- Piping & Instrumentation Diagrams
- Cause & Effect Matrix
- Hazardous Area Classification Drawings
- The document pertains to the guidelines, operating procedures, and health, safety, and environmental (HSE) philosophies of the company.
- Incident reports
- Facility Risk Register
The HAZOP analysis proceeds systematically by examining each node of the plant in succession. The Facilitator makes the selection of the node sizes and the route through the plant before the study.
The node ought to be explicated in terms of:
- Brief description of the node
- Typical operating and design conditions
Guidewords refer to uncomplicated terms or expressions utilized to specify or measure the purpose and related parameters, with the aim of proposing deviations.
- No, Low/ Less, More/ High, Reverse/ Misdirected, Less/ More.
Typical parameters/elements considered for HAZOP are as follows
- Flow, Pressure, Temperature, Level, Viscosity
- Composition, Contamination
- Operation, Start-up, Shutdown, Maintenance, Isolation
- Sampling
- Corrosion
- Operability & Maintenance Issues
- Safety
- Instrumentation & Control
Deviation refers to the instances where the process design intent is not followed. The combination of parameters and guidewords in sequence are identified all the deviations (no flow, more temperature etc.). It is possible that there exists a noteworthy degree of overlap among the deviations under consideration, such as the possibility that the absence of flow could produce an effect equivalent to that of increased pressure.
The team will engage in a collaborative process of ideation to identify all plausible factors contributing to the observed deviation. All potential causes should be identified and discussed, as the consequences and actions may be different. Causes are always local or within the node only. If possible, it has been consolidated and limited to the node under discussion.
There exist three primary classifications of causes, ranked in descending order of likelihood:
- Human error
- Equipment failure
- External events
It may be noted that “cause” in worksheet is explicitly worded including one tag. This implies/ includes other corresponding tags for parallel equipment. The potential consequences for each cause are discussed and assessed within the limits of the information available and the expertise of the team. There may be several consequences involving escalation to other pieces of equipment.
All important consequences anywhere in the facility, resulting from the cause are listed out. Worst-case consequences are described assuming that no safeguards are in place or working.
The HAZOP study is executed in a methodical manner, utilizing a step-by-step approach.
- Choose a particular system. Please provide more context or information about the subject matter that you want me to rewrite academically.
- Choose a specific node, which refers to a localized area of focus, within the designated system. Typically, a system comprises a vessel and its associated piping or a pump and its corresponding piping. Please provide more context or information about what “it” refers to in this sentence so I can accurately rewrite it in academic language.
- Utilize the initial operational parameter, such as flow rate or pressure. In order to establish a deviation, a possible guideword such as “No” can be applied to the parameter. Insufficient fluidity or lack of coherence in the written or spoken discourse.
- To analyze the deviation, it is necessary to examine the potential causes and consequences, including any associated risks and the safeguards that are currently in place. Suggest implementing supplementary measures for enhanced safeguarding, if deemed appropriate.
- Iterate the aforementioned process for all guide words that are relevant to the chosen parameter.
- Iterate this process for all of the parameters.
- The node is fully formed. Iterate over all nodes within the system to ensure that all components have been fully processed and accounted for. Upon completion of this process, the system can be deemed fully operational and functional. Reiterate the aforementioned process for all the systems present in the plant.
Controls that prevent the cause from occurring, and/ or alert the Operator when deviations occur, and/ or mitigate the consequences should the cause occur are known as “safeguards”. They include, for example:
- Those systems, engineered designs and written procedures, which are designed to prevent a catastrophic release of hazardous or flammable material.
- Those systems are specifically engineered to identify and provide timely notification subsequent to the onset of a hazardous or combustible substance discharge.
- The aforementioned refers to the set of protocols or documented measures that serve to alleviate the impact of a hazardous or flammable substance discharge.
It is further noted that, positive isolation procedure is followed while handling over any facility for maintenance work such as control valve maintenance, which requires breaking the flange, etc. Once the key safeguards are listed, the team then evaluates the listed Safeguards based on adequacy to eliminate or maintain the potential risks within tolerable limits.
During the HAZOP session, the study team engaged in a systematic brainstorming process to evaluate the process under review in the scheduled meeting. This was accomplished through the use of a set of Guidewords, which were employed to structure the review. The study team is composed of individuals representing a variety of departments/specialties.
The following procedure is adopted during the HAZOP workshop:
- Selecting a Node (i.e. vessel or line) to be assessed;
- Describing the purpose and design of the Node by a Process Engineer or an Operation Representative;
- Identifying a potential Deviation that may occur within that Node using a Guideword and Parameter;
- Identifying and evaluating the Causes for the Deviations from the design intent;
- Evaluating the potential Consequences from the Deviations addressed, without considering any Safeguards in place;
- Identifying any Safeguards in place in order to prevent the failure scenario from occurring or mitigate the Consequences if it occurs;
- Recommendations are raised to mitigate the Consequences further, wherever required.
The HAZOP Report encompasses the action items that were identified as recommendations during the HAZOP Study. Each recommendation suggested by the HAZOP team was proposed to reduce the risk of a hazard scenario to an acceptable level of risk (as determined by the HAZOP team). Should a recommendation not be implemented, the HAZOP Action sheet must identify an alternate action to achieve the required risk reduction, or document the basis for reassessing the risks and determining that the risk without the recommendation is within acceptable levels. It should be noted that the responses to the HAZOP recommendations should provide a clear audit trail including the reasons for taking or not taking action.
