28-06-2012, 06:05 PM
DURABILITY INCREASE OF FIELD PIPELINES SUBJECTED TO
GROOVING CORROSION
DURABILITY INCREASE OF FIELD.pdf (Size: 664.29 KB / Downloads: 39)
The analysis of fault rates of field pipelines shows, that to one of the principal causes
causing refusal is groove fretting on the bottom forming internal surface of a wall of a pipe.
It is caused complex is intense - deformed by a condition of the pipeline, simultaneous
influence on metal of water contained in petroleum, gas and using up influence of abrasive
particles [1]. As a rule, in these conditions pipelines are laid without external isolation since
speed of the groove fretting attain 2 … 3 mm / year, and term of operation is reduced
sometimes till 3 years.
The offered method of increase of term of operation of the pipeline subject to groove
fretting, consists that on the struck site turn the pipeline be relative its longitudinal axis on
some angle ϕ (fig. 1). In the result, the available groove moves from a zone of active
destruction in a zone protected from its formation. Residual thickness of a wall of the pipeline
in the groove before performance of turn should be not less safe operation of the pipeline
admitted from a condition.