Introduction
In the ever-evolving landscape of energy distribution, safety and regulatory compliance are critical. iFluids Engineering conducted a comprehensive HAZOP (Hazard and Operability) and QRA (Quantitative Risk Assessment) study for the CNG and CGS stations in Warangal, a project of Megha City Gas Distribution. This analysis, aligned with the Petroleum and Natural Gas Regulatory Board (PNGRB) regulations, reinforces our commitment to ensuring safe, sustainable operations in the heart of Telangana.
- An energy-efficient India is the goal of Megha City Gas Distribution Pvt. Ltd, a division of Megha Engineering and Infrastructures Limited (MEIL).
- By providing green fuels like compressed natural gas (CNG) for automobiles and piped natural gas (PNG) for residential, commercial, and industrial users, it meets the nation’s energy needs.
- It also builds CNG stations, City Gate stations (mother stations), main and distributary network pipelines.
- The MDPE Pipeline in the MCGDPL-Warangal region provides CNG distribution to Narsampet and the Warangal region.
- The QRA research was carried out using the MDPE Pipeline documents that were available, and the study’s summary and conclusions apply to MDPE Pipelines that supply Megha City Gas Distribution Pvt Ltd-Narsampet CGS with CNG distribution to the Narsampet and Warangal regions.
What is a HAZOP and QRA Study?
HAZOP (Hazard and Operability Study): This is a systematic approach to identifying potential hazards (like leaks, equipment failures, etc.) and operability problems within an industrial setup. By evaluating each part of the gas station and distribution system, the study ensures there are preventive measures in place to minimize risk. This keeps both the equipment and nearby community safe.
QRA (Quantitative Risk Assessment): This study uses data and modeling to measure the risk levels associated with different parts of the system. It calculates the probability and possible consequences of various events (like accidental gas leaks). Based on these insights, it guides the design and emergency response plans to minimize risks effectively.
The CNG stations are classified into the following categories:
- Online stations
- Mother Stations
- Daughter Booster Stations
- Daughter Stations
- City Gas Distribution (CGD) System Overview:
- Supplies piped natural gas (PNG) to residential, commercial, and industrial clients within a city or town.
- Receives high-pressure, deodorized gas through a transmission line from the transporter.
- Processes gas at the City Gate Station (CGS) with filtering, pressure reduction, odorization, and metering before distribution to end-users.
- Pressure Reduction Stages:
- Pressure is lowered in a four-stage process:
- CGS: Initial pressure reduction and odorization.
- District Regulating Station (DRS): Secondary pressure reduction.
- Service Regulator: Tertiary pressure reduction at neighborhood level.
- Customer Residence: Final reduction to safe use levels.
- Pressure is lowered in a four-stage process:
- Odorization System:
- Installed at CGS to impart a detectable smell to the gas, ensuring leak detection for safety
- Key Assets in the CGD Network:
- City Gate Station (CGS).
- Underground MDPE distribution network.
- District Regulating Station (DRS).
- Medium Pressure Polyethylene (MP PE) network.
- Service regulators for further pressure control.
- Low Pressure Polyethylene (LP PE) network.
- Customer connections for end-user access.
- Compressed Natural Gas (CNG) Station Operations:
- Sources natural gas (NG) from neighboring mother stations at pressures over 200 bar.
- Receives gas through either a movable cascade or pipeline operating between 19-22 bar.
- Gas compression stages:
- Mother Stations: Compresses NG for Online and Cascade Dispensing Units (DU).
- Daughter Booster Stations: Compresses NG to 250 bar for Dispensing Units (DU).
- Daughter Stations: Supplies gas directly to DU without compression.
- Scope of Risk Evaluation:
- Focuses exclusively on risk factors associated with CGD and CNG facilities during project operations.
- Does not include any facilities outside the scope of the proposed activities.
The QRA study for the Project includes coverage for the following facilities.
- MDPE Pipeline, Warangal GA – This study’s primary goal is to methodically and quantitatively assess the possible hazards connected to a given circumstance, course of action, or choice.
- The following are QRA’s objectives:
- Involves assessing and quantifying risks in various scenarios through the use of numerical data and analysis.
- Facilitates educated decision-making by providing options.
- Gives risks numerical values so that they can be compared and prioritized.
- Offer stakeholders a methodical and transparent means of receiving information about risks.
- Offer stakeholders a methodical and transparent means of receiving information about risks.
- Evaluate the cost-effectiveness of various risk management techniques by contrasting the anticipated benefits of risk reduction with the possible costs of risk mitigation measures.
- The following are QRA’s objectives:
Pipeline Segmentation: Two sections of the MDPE Pipeline in Warangal, divided into 90mm and 63mm pipelines.
- Isolation Scenarios:
- 14 station isolation scenarios for each pipeline type.
- 11 pipeline isolation scenarios for each pipeline type.
- Consequence Analysis Using DNV PHAST 8.4:
- Identified major potential events, including:
- Fireball
- Flash Fire
- Overpressure Explosion
- Jet Fire
- Assessed effects and implications for each scenario.
- Identified major potential events, including:
- Conducted a risk assessment, generating:
- F-N Curve (Frequency vs. Number of Fatalities)
- LSIR (Location-Specific Individual Risk) Contours
- Risk Results Evaluation:
- Based on the Risk Acceptance Criteria:
- Societal risk and Individual Risk Per Annum (IRPA) predominantly fall within the ACCEPTABLE range.
- Based on the Risk Acceptance Criteria:
Conclusion:
In alignment with PNGRB regulations, the HAZOP and QRA studies for the CNG station, CGS station, and Megha City Gas distribution line in Warangal demonstrate a comprehensive approach to identifying and mitigating potential risks. By using advanced tools such as DNV PHAST and SAFETI 8.4, these analyses ensure that safety protocols not only protect personnel and infrastructure but also support the surrounding communities. The findings emphasize proactive risk management, ensuring that societal and individual risks fall within acceptable limits, underscoring a strong commitment to safety and regulatory compliance.
If you’re seeking expert guidance on gas distribution safety or compliance with PNGRB standards, reach out to us at iFluids Engineering. Let our industry-leading team help secure your project with tailored safety solutions that align with best practices and regulatory requirements. Contact us today to learn more about our safety and risk management services.