GAIL (India) Limited awarded iFluids Engineering to carry out Quantitative and Qualitative Risk Assessment (QRA) study for their 278 km long Cross country Pipeline in Cauvery Basin. The scope of study is to systematically identify the potential hazards associated with GAIL pipelines, respective terminals and SV stations through risk assessment methodologies.

Brief on Client and the Location-specific details
GAIL (India) Limited was incorporated in August 1984 as a Central Public Sector Undertaking (PSU) under the Ministry of Petroleum & Natural Gas. It is the largest state-owned natural gas processing & distribution company.

Pipeline Specification details and what it transports

LIST OF STATION/INSTALLATIONS (RISK ANALYSIS) AT CB PIPE LINE NETWORK

• Dispatch Terminals/Gas Collecting Station

Risk Index Method
The risk factor is an important parameter that determines the ways to develop a Risk Assessment model, using either a data first or a frame first model. Since pipelines usually go across many regions whose conditions vary significantly, it is important to have a complete and universally accepted list of factors that can be used to build a risk assessment model. Risk assessment model parameters viz. Third-Party, Corrosion, Design, and Incorrect Operation would then be summed up and multiplied by the leaked impact (based on Product Hazard, Dispersion, Leak volume, and Receptors) shall be used for assessment of the pipeline integrity

Why Risk Assessment is carried out for pipelines?
Risk Assessment of the pipelines is conducted to identify the location-specific events or conditions, or combination of events and conditions that could lead to loss of pipeline integrity, and provides an understanding of the likelihood and consequences of these events.

This identification of location-specific risks were carried out in consultation with GAIL after analyzing the data like Pipeline routing drawings, mechanical data, CP (Cathodic Protection) data, construction details, historic leak /rupture data, O&M philosophy etc. Which was provided by GAIL. These risks shall be rated as Low, Medium and High as per the risk assessment criteria.

PNGRB guidelines represent 22 root causes for the threat to pipeline integrity. One of the cases reported by the operator is "unknown". The remaining 21 threats have been classified into three groups based on time dependency and further into nine categories of related failure types according to their nature and growth characteristic as shown below

Risk Assessment Methodology

The Risk Assessment Study includes the following steps:

How to evaluate the residual life to minimize failures and sustain pipeline operations.?

Following test methods as per OISD -SOP- Integrity assessment of Petroleum and Natural Gas Pipelines should be performed for pipelines crossing 25 years of design life to assess the health of the pipeline :

Software Used:

DNGVL PHAST SAFETI 8.22

Recommendations

The Recommendation is done as per the OISD Standards and best Engineering practices