The remote wellhead jackets (WHJ) are provided with telemetry system comprising a Remote Telemetry Unit (RTU) installed on each jacket and a Master Telemetry Unit (MTU) located at the production stations. The MTUs at the stations receive wellhead data from the respective RTUs and are interfaced with the Yokogawa DCS on the stations via OPC (Open Platform Communications).
The existing telemetry systems are very old, do not cover all the WHJs and are not able to cope up with the on-going Intelligent Oilfield technology development, and the increasing demands in operational requirements such as, new well hook-ups, remote operation of wells, remote well testing etc.
In addition, the existing system has its own limitations with respect to expansion, modification and interface with the DCS. This poses major constraint on hook-up of new wells, monitoring, control and operation of wellhead facilities directly from DCS. Hence, the Telemetry risk assessment is carried out for the above-mentioned facility.
The aim of Risk assessment shall be as follows:
- The effective management of project risk involves the timely identification of potential hazards and the implementation of measures to mitigate the likelihood and severity of any adverse incident that may negatively impact personnel, plant, properties, and the environment. This is particularly relevant in the context of the transfer of monitoring and control functions from an existing RTU to a new Telemetry system, which forms an integral part of the installation and commissioning process.
- Identifying and evaluating the hazard and risk due to the interference of Electro Magnetic Interferences and Radio Frequency Interferences to the existing communication equipment on the WHJ
The process of risk assessment study sequence can be comprehended optimally by dividing it into the subsequent steps:
- Communicating and consulting throughout the process
- Establishing the context
- Risk Assessment – an overall process involving risk identifying, risk analysis, and risk evaluating
- Risk treatment
- Monitoring and reviewing risks;
- Reporting and recording the results appropriately.
The following techniques are commonly utilized at each stage of the comprehensive risk assessment procedure.
The process of risk assessment study sequence can be comprehended in a more effective manner by dividing it into the subsequent steps:
- Choose the suitable segment or region of the botanical organism.
- Define the design intent of the area and process conditions.
- Select the first/next Hazard Category.
- Utilize the initial/subsequent guide term in conjunction with the Hazard Category to derive the potential hazard situations.
- Determine (by brainstorming) all the potential causes of the hazards.
- Reach a consensus regarding the veracity of every underlying factor.
- Evaluate the ramifications of each causal factor, as well as the efficacy of the safeguards and preventative measures implemented to mitigate both the causes and their resultant effects.
- Assess the likelihood of each hazard.
- Assign a risk level for each hazard using the Risk Assessment Matrix. The assignment of risk level shall take into account the implementation of standard controls and consideration of all relevant safeguards incorporated into the design.
- Agree on a recommendation for action or further consideration of the problem (if applicable).
- Utilize the following guide term that is pertinent to the chosen category of hazard.
- Apply the next Hazard Category until they have all been considered.
- Proceed to the subsequent section of the plant or project until a comprehensive assessment of the entire study area has been conducted.
The criteria for accepting risks are categorized based on the assessments’ purpose and level of detail:
This study aims to establish high-level risk acceptance criteria for quantitative assessments of new projects or major modifications to onshore/offshore installations. The criteria will incorporate the ALARP principle, including F-N for societal risk calculations; Risk Assessment Matrixes and the ALARP principle for semi-quantitative and qualitative risk analyses.
The Localized Spatial Index of Risk (LSIR) is utilized to denote the aggregated risk level present at a specific geographical point. The LSIR pertains to the potential risk that an individual may face if they were to occupy a specific location continuously for 24 hours a day, 365 days a year. An individual risk criterion is intended to demonstrate that workers are not exposed to excessive risks, and activities do not impose any additional risks on the members of public. The target individual risk level for workers is an IR of less than 10-6 per year.
Individual Risk Criteria is defined in three regions viz; the UNACCEPTABLE region, the TOLERABLE OR ALARP region and the BROADLY ACCEPTABLE region, as depicted below
The concept of societal risk pertains to the level of risk encountered by a specific population of individuals who are subjected to certain hazards within a defined timeframe. The severity of a hazard and the number of individuals within its range are reflected. The term typically pertains to the probability of mortality and is quantified as an annual risk. Societal risk is also defined as the relationship between frequency and the number of people suffering a given level of harm from the realization of specified hazards.
The Societal Risk Criteria is as follows
Recommendation (Action / query items) are recorded and the corresponding Risk Assessment Action Sheet shall be generated for subsequent follow-up and close out by the project.
The Project Engineer have the responsibility to ensure appropriate project follow-up of the action recommendations generated during the review are implemented.
It is imperative to establish specific action plans for all identified risks, with the quantity of such plans being subject to variation depending on the nature of the risk in question. However, at any point in time, each task in an action plan has a particular status, such as completed or on-track or considered as non-executable. In either cases risk reduction and residual risk specific to a project at each stage shall be monitored. A Hazards and Effects register is a useful tool to monitor and track risks, controls and residual risk specific to a project.
An H&E register should be unique to a project and the risks identified during safety studies should be recorded to this register. It is recommended that the H&E register be regularly updated during the course of the project, incorporating insights from routine design activities, safety evaluations such as HAZOP, HAZID, and QRA, among others. This practice should be beneficial to track and monitor project hazards during the life cycle of the project. Project engineer should be primarily responsible for maintaining the H&E register for their project.
