Page 250 - Pipeline Pigging Technology

Pigging and chemical treatment

Fig.4. Downward-sloping multi-phase flow.
several years, due to corrosion of the upper portion of the pipe in down-
sloping sections of the line. The operator changed the application of inhibitor
to a batch method between pigs, to ensure that the complete surface of the
pipe wall would be treated and protected against further corrosion.

BIOCIDE TREATMENT OF PIPELINES

Control of bacteria and bacterially-induced corrosion in pipelines is
another area where application of the chemicals used is greatly enhanced
when applied in conjunction with pigging. Anaerobic sulphate-reducing
bacteria (SRB) and anaerobic acid-producing bacteria (APB), are two types of
bacteria commonly found in oil and gas pipelines. SRBs produce hydrogen
sulphide, while APBs generate acetic acid, both of which are highly corrosive.

Pipeline bacteria

Bacteria live in water, but prefer to grow on metal surfaces. Once bacteria
establish as viable colonies on the pipe wall, they protect themselves with a

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