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Kashagan pipe "in a hole"?

November 8 2013, 09:55

By Saule Tasboulatova

One month passed since the second leak (during a short period) in the pipeline coming to Bolashak processing facility. The public still doesn't know anything about the reasons of pipeline failures neither in the first, nor in the second cases.

All we know is that Oxford university experts are involved in the investigation, who came to Atyrau right after the accidents and took away with them the fragments of pipes. Since it is difficult to obtain any sound information from official sources, we were obliged to refer to informal sources, who told us about inevitable shutdown of commercial production at Kashagan - at least for a year.

Insignificant Incident

NCOC in their press releases confirm the facts of accidents, but at the same time the company tries to calm down the public by saying that such “insignificant incidents” are inevitable during the start-up of such complex facilities. Nevertheless, the fact of prolonged investigation of the accidents gives grounds for thinking that the situation is much more serious. So, let’s try to clarify the situation.

Three pipelines are laid between the the point of commercial production - D island and Bolashak processing facility. The first two pipelines are for crude oil and gas. The extracted crude goes through the process of initial separation and drying at D island and then is pumped via two separate pipelines to Bolashak plant for the final treatment from sulphur and other elements. The treated gas then is pumped through the third pipeline back to D island for operational needs.

Heavy-duty pipeline sections, made of carbon steel, were supplied by the Japanese Mitsui&Co.Ltd. The source familiar with the matter said that the world hasn’t invented more suitable alloys of steel for the existing medium. Why such heavy-duty pipes don't resist the aggressive impact of hydrogen sulphide? This question still remains unanswered.

Oxford Was Involved

Company documents state that pipeline leaks are caused by SSC - sulphide stress corrosion cracking. Pipes affected by SSC get very brittle.

The company reports state about insignificant leaks. But if those leaks occur 1 meter under the sea bed, then we can only guess about the scales of those leaks.

Erbol Kuanov, the head of Atyrau oblast ecology department, keeps silent about the results of investigation. We don't know neither about the volumes of emissions, nor the extent of impact on environment.

Information provided by the local emergency situations department is also very scarce. They only confirmed the arrival of experts from Oxford. Acting emergency situations department head Kabylbek Kistaubaev said the following over the phone:

– We suspended the investigation and we are waiting for the experts’ conclusion from Oxford University. They took away pipeline fragments.

According to Kistaubaev, the pipes that local H2S turned into “cloth” were replaced by the same pipes.

 Expert From Outside

I talked to a pipeline engineer, the source familiar with the matter, who provided the following comments:

-  Agip has rigid specification requirements for both offshore and onshore pipelines. Unfortunately, I only have specifications for onshore pipeline and I cannot tell what pipeline requirements Agip uses for offshore part. In any case, those materials should be highly resistant to corrosion with external and internal anticorrosive coating.

Pipeline cracking happens due to chemical impact of sour medium (crude oil with presence of H2S or sour gas) to internal wall of a pipe. Two factors may have provoked such cracking: 1 . Wrong material was used in violation of Agip specifications, or 2. Wrong assessment of medium corrosion properties. Corrosion cracking doesn’t happen due to improper operation. Several years of idle time of pipeline don’t affect the pipe quality.

Because cracking took place on the body of the pipeline and not in seams, we can presume that the problem is in the material. It is all unclear to me, first they said that there were leaks caused by induced cracking, then those leaks stopped. They cannot stop by themselves, they can only get worse and they are permanent. Gas pipeline rupture due to high pressure is possible, but improbable, because the materials are normally chosen with a high safety factor.

If we are indeed talking about sulphide stress corrosion cracking then the pipeline system should be fully replaced, in my opinion. It is inevitable”.

Delay Is Inevitable

Summing up what has been said, the situation at Kashagan is very serious. Hans Wenck, NCOC External Communications manager, to our inquiry replied the following: “The oil and gas production at the Kashagan field is suspended until inspection work is complete and the results of experts are received. After that it will be possible to restart the facility safely. While investigation is ongoing, it is premature to speak about any repair work or deadlines required for their implementation. Taking into account the time required for investigation of root causes of leaks by the experts, the production of considerable volumes of oil or gas until the end of 2013 is not expected …

Within the framework of further preventive measures currently the sections of the onshore parts of the gas pipeline are being uncovered to allow a thorough visual inspection. The offshore part of the pipeline is being monitored carefully using vessels and helicopters equipped with sensors to detect potential gas seeps. No anomalies have been noticed. Experts are investigating the root cause of the pipeline events. It is anticipated that the activities relevant to inspections and investigations will take some weeks.”

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