20 / 100
The state of India’s pipeline failures
Even as India moves ahead with the extension of its gas
pipeline network for greater application of the cleaner fuel
option of natural gas, the June 2014 incident of gas pipeline
failure that led to 22 casualties in Andhra Pradesh is deeply
ingrained in people’s memories. As noted by the Petroleum
and Natural Gas Regulatory Board (PNGRB), the greatest
number of pipeline failures recorded in India is through
third-party damage (Figure 1).
India’s pipeline systems are still in a developing stage
and most of the pipelines are yet to reach a point where
replacement becomes important. However, there have been
incidents of internal corrosion due to non-incorporation
of gas specifications in the gas sale agreement and non-
installation of gas dehydration units (GDU), which has
reduced the life of pipeline assets, requiring them to be
replaced in four to five years’ time – as noted by PNGRB’s
probe of the Tatipaka-Kondapalli Pipeline (TKPL) incident.
Lessons from pipeline incidents
The TKPL incident is the most cited case of pipeline failure
in India, as it offers several lessons for other pipeline
operators. These lessons have prompted all pipeline
operators to take serious note of the recommendations
after the 2014 incident, besides implementation of directives
and regulations, more stringently than ever.
On 27 June 2014, the devastating fire at the state-
run gas pipeline operator, TKPL, occurred in Andhra
Pradesh, which killed 22 people and injured 18 others. The
18 in. OD × 7.11 mm pipeline was commissioned in 2001
by the operator to move dry natural gas to downstream
consumers from one of the leading upstream petroleum
company’s fields in India, but instead the pipeline carried
wet gas. This wet gas contained free water, carbon dioxide,
and sulfur that induced internal corrosion in the pipeline
and resulted in gas and condensate leaking to the surface.
When a stove was lit near the pipeline, the leaking product
caused a blast, which was followed by fire. As per the
PNGRB’s probe, the intensity of the explosion was such that
it fractured the pipeline, with an approximately 2 m length
portion ripped open and thrown 5 m away, impacting the
nearby dwelling units, houses, tea stalls, and coconut trees
spread over a 50 m radius.
After the probe conducted by the PNGRB and later by
the Comptroller and Auditor General of India (CAG) in its
audit of ‘Safety Preparedness of Oil and Gas Transmission
Pipelines’, the following causes for pipeline failure were
observed.
Corrosion
According to the PNGRB’s probe report, wet gas was in the
pipeline that was designed for dry gas, which therefore
did not meet the requirement of sub-regulations 5(5) and
8(1)(b) of the PNGRB’s 2008 regulation ‘Access Code for
Common Carrier or Contract Carrier Natural Gas Pipelines’.
The report also stated that the pipeline operator flouted
the declaration to the statutory authority as well as the
declared design basis by not providing GDUs at Tatipaka
and Mori, the absence of which led to an increase in the
pipeline’s corrosion rate.
In this regard, the pipeline operator did not comply with
the recommendations of the fitness-for-purpose report
(submitted in 2013 on the basis of an inline inspection
carried out in 2010); for example, the use of an effective
corrosion inhibitor in conjunction with operational
cleaning/dewatering pig runs whilst transporting wet gas.
Consequently, as per the CAG report, various pipelines
were corroded and needed replacing within a short period
of 4 - 10 years, against the designed operational life of
20 years.
Moreover, according to this report, where an intelligent
pigging survey is conducted to assess the health of a
pipeline through ILI of active pipelines for signs of metal
loss, corrosion or dents within 10 years from the date of
commissioning, the delay was found to actually range
from 1 - 17 years in the implementation of 66 pipelines
for piggable sections, and 1 - 4 years for non-piggable
sections in 46 pipelines – noticed in the case of the state-
owned gas pipeline operator. This was also non-adherence
to the PNGRB 2009 regulation: Technical Standards and
Specifications including Safety Standards for Natural Gas
Pipelines. Similarly, due to off-specification gas provided
by the aforementioned upstream company’s gas fields
of Ponnamada, Kesanapalli and Adavipalem, there was
extensive internal corrosion and reduction of pipeline
thickness, which led to fire breaking out on the Ponnamada-
Kadali natural gas pipeline. This resulted in huge damage to
nearby agriculture and property.
Third-party damage
As noted by PNGRB in its 2012 - 2013 analysis, third-party
damage has been the most prominent reason for pipeline
failure, with its number reaching as high as 2116. However,
there was an incident where a fire erupted in the state-
owned pipeline operator’s 12 in. natural gas pipeline, due
to gas leakage caused by a public works department
(PWD) contractor. The contractor was undertaking a soil
investigation survey by drilling at the affected location
without any intimation or permission from the pipeline
operator. This incident was the result of the absence of
technical supervision of both the operator and PWD,
Figure 1.
Causes of pipeline incidents. Source: PNGRB.
18
World Pipelines
/
MARCH 2020