Ravva - Cairn’s first development success story has been the bedrock of innovation, and the foundation of our success story in the country and the region. Ravva, which in Sanskrit and Telegu means “diamond” showcases the journey of growth that Cairn has been able to achieve in its business. Incidentally, Ravva is the only field in India to get such a unique name indicating the belief of the nation in it.

1.
RAVVA
Celebrating 16 Years of Technical Excellence
HSE | Cathodic Protection

2. Ravva | HSE
Cathodic Protection
One of the major causes of concern for an installation, like Ravva is the corrosion of underground metal
structures. All metals are naturally prone to corrosion, depending on the severity of the environment.
Corrosion is the disintegration of material into its constituent atoms due to chemical reactions with its
surroundings.
The principal methods for mitigating
corrosion of underground pipelines are
Coatings and Cathodic Protection (CP).
The primary function of a coating on a
cathodically protected structure is to
reduce the surface area of exposed
metal on the pipeline, thereby reducing
the necessity to cathodically protect the
metal.
CP is defined as ‘a reduction of the corrosion rate by shifting the potential of the structure toward a less
oxidising potential by applying an external current’.
During the design/construction phase at the Ravva plant all the possible protections were provided.
However, due to the ageing and environmental effects, regular monitoring for various degradation
processes has become necessary.
Monthly monitoring schedules are followed at Ravva to check health of the pipelines through the test
stations provided in the pipeline corridor for all 13 lines (including newly laid pipelines as part of the Ravva
Pipeline Project).
Cairn initiated Closed Interval Potential Survey (CIPS) for the onshore pipelines ( i.e Plant to Land Fall
point) to check the potentials at very close intervals (at every 5 m).
Over-the-line potential surveys provide measurement of potentials to a reference electrode directly above
the pipe, and at frequent intervals along the pipe; survey results can be used to locate the more actively
corroding areas (hotspots) on a pipeline not under CP or areas of depressed potentials on cathodically
protected pipelines.
Highlights of CIPS are:
 Monitoring the potential of the pipelines from plant to land fall point.
 Potential measurement at an interval of 5 metres
 Survey awarded to reputed organisations – for about 3 weeks, surveying through the marshy
pipeline tracks
 Results proved that all pipelines are in the protection range (0.85-1.2 V)