HAZID study has been developed specifically to reflect the importance of HSE issues on fundamental decisions that are made at the inception of all development projects (e.g. design concept and location). HAZID is the first opportunity to collect experienced line and HSE staff together to address, in a short timeframe, the issues surrounding a new venture or development or modification project.
The facility description for which the HAZID study has been carried out is described as follows.
Acid Gas Removal unit (AGR Unit) solvent absorb Acid gases from the Natural Gas Feed in all South trains. The amine solvent in the Absorber absorbs acid gases. The absorbed rich solvent acid gas is flashed in Rich solvent flash drum and is sent to the Fuel Gas header. Flash gas contains valuable NGLs. As per existing design, all trains AGR Flash Gases are sent to Utilities system which is loss of valuable NGLs. The main intent of this study is to recover (maximum) valuable NGL products (Propane, Butane and Heavy Hydrocarbons etc.).
The HAZID technique includes the following:
- The objective is to identify and describe health, safety, and environmental hazards and risks as soon as possible during the initiation of a project or undertaking.
- A gathering of a proficient and diverse group of individuals utilizing a systematic brainstorming approach, founded on a comprehensive list of plausible health, safety, and environmental concerns, to evaluate the relevance of potential dangers.
- Conduct a qualitative assessment of risks in order to rank the hazards.
- The process of identifying and describing potential problems is conducted expeditiously, with the sole purpose of recognizing issues rather than attempting to resolve them.
- The HAZID is a structured approach to determine the potential impacts of the following;
- The surroundings on the facilities.
- The facilities on their surroundings.
- The facilities on the health
- Project Implementation Issues
HAZID review is to identify potentially dangerous and undesirable events, which might affect a facility (equipment, operators, and production). The review allows proper identification of HSE hazards at the beginning of a project and provides a detailed list of project hazards and recommended controls to manage those hazards to an acceptable level of risk. The review also describes the causes and consequences of these hazard scenarios and provides recommendations that propose.
- Mitigation measures that will eliminate the risk of occurrence of these events or limit their consequences
- Investigations and studies to quantify the risks and possible consequences
The ultimate goal of the HAZID review is to identify potential hazards and manage the risk of those hazards to an acceptable level of risk.
The HAZID technique is designed to identify and mitigate risks associated with design decisions made in the early stages of the project. By identifying these risks early in the design phase, the cost and schedule impact associated with the risk reduction measures is minimized. The HAZID process provides an initial platform for proficient line and HSE personnel to convene and examine the concerns associated with a novel undertaking or alteration project.
The HAZID methodology will be using structured brainstorming sessions prompted by hazard guidewords. The following methodology has been adopted for the HAZID review.
The team identify a series of likelihood events and scenario, which could give rise to a hazardous condition, without considering the design features or integrity of the systems. However, while assigning the risk level, existing and normal controls & safeguard shall be considered in place referred to latest revision of the documents.
The HAZID team systematically chooses the appropriate Hazard Category and corresponding Guide Word that are relevant to the designated area.
Guidewords can be used to assist in the identification of hazards, the causes, the hazardous scenarios and the potential consequences.
The HAZID Team brainstorms to identify possible Causes for the hazard scenario considered and all possible Causes should be recorded.
For clarity purposes, it is better that all causes recorded should be numbered so that a person can track the corresponding consequence(s), prevention(s), and protection(s).
Once the team identified all credible causes for the hazard scenario, their likely consequences are studied and recorded by considering all credible ultimate consequences without safeguards. The attribution of consequences is facilitated through the use of suitable numerical identifiers that link them to the corresponding hazard scenarios.
Preventions and Protections shall then be identified by the team, preferably in the order which are implemented. The risk reduction hierarchy should be followed, including the final measure where appropriate.
Based on the team experience of the consequence and the likelihood, risk rank should be assigned to each hazard scenario using Risk Assessment Matrix (RAM). Each hazard/ accident scenario that has the potential for harm to personnel, the environment, the asset or reputation, will be graded with respects to ‘likelihood of occurrence’ and ‘severity of consequences’.
This grading will provide a risk rating that can be compared against criteria. The purpose of this is to firstly, help determine the need for additional safeguards, and secondly, identify the type of safeguards needed (if any).
For each risk that is ranked in the ALARP region, the team will consider and make a statement as to whether, based on the current understanding of the design, that all practicable measures have been incorporated in the design, and hence that the risk as assessed is ALARP. This statement will be used in to support the argument that the overall design is ALARP.
This statement is not necessary or applicable for risks that are ranked in the intolerable or tolerable regions. If there are any risks in the intolerable region, these will need to be reviewed by COMPANY and may be taken forward for further detailed evaluation.
The proceedings file of the HAZID are recorded and Risk treatment plan (recommendation/ action/ query items) are recorded and the corresponding HAZID Close Out Action Sheet (Appendix E) are generated for subsequent follow-up and close out by responsible action party. It is accountable for projects team to track and close out all HAZID Study risk treatment plan/ recommendation.
For those deviations that are considered by the HAZID study team to be credible, the following information was recorded in the HAZID worksheet.
Recommendations include design, operating, or maintenance changes that reduce or eliminate Deviations, Causes and/or Consequences.
During the study, the team discussed all possible causes of each deviation from the design intent and listed them. Once all causes were documented, the team focused on the consequences for each identified cause. The consequences documented were those that may credibly arise, given that the cause occurred. Once the consequences were documented, the team reviewed the process design and operations for safeguards that would prevent, detect, or mitigate each cause/consequence scenario. Any recommendations made are for additional safeguards that are not currently in use at the facility.
The purpose of the recommendations is to:
- Reduce the probability of occurrence of an incident;
- Reduce the severity of the consequences, in the event the incident was to occur;
- Request further information, when the scenario could not be fully described owing to a lack of data or Request an update or addition of a particular document.
