Oil & Natural Gas Corporation Ltd. (ONGC) operates a 42” gas pipeline that originates from an offshore platform and terminates at an onshore plant. The pipeline has operated for two decades and transmits 17% of India’s gas needs.
Unfortunately, the buried pipeline became exposed at Landfall Beach, likely due to the unpredictable impact of natural forces over a period of time. The shifting shoreline eroded resulting in the pipeline being exposed, which threatened its integrity. Stopgap arrangments were made to protect the pipeline from being hit and moved by continual tides, but that temporary measure also proved ineffective against the forces of the nature. The seasonal tropical storms worsened the situation.
ONGC rose to the challenge and decided to carry out permanent remedial measures, including re-routing of the affected segment of the pipeline and its associated station valve.
The situation presented several challenges. Because the pipeline was responsible for a large percentage of India’s gas needs, it was important to keep the pipeline live. Additionally, the worksite was a popular beach recreation area, so safety was a top priority.
ONGC contacted T.D. Williamson India Private Ltd. (TDW) for an isolation solution using double block and bleed methodogy to meet both of these concerns.