Caroline pipeline failure: Findings on corrosion mechanisms in wet sour gas systems containing significant CO{sub 2}

Conference · Thu Aug 01 04:00:00 EDT 1996

OSTI ID:268173

Bich, N N ^[1]; Goerz, K ^[2]

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1. Shell Canada Ltd., Calgary, Alberta (Canada)
2. Shell Canada Ltd., Caroline, Alberta (Canada)

A leak occurred in the 5-32S flowline between Junction 1 and the South Compressor Station in the Canada Limited Caroline Complex gathering system near Sundre, Alberta, due to internal wet H{sub 2}S (hydrogen sulfide) and CO{sub 2} (carbon dioxide) pitting corrosion at the bottom of the pipeline. The significant contributing factors to the extremely high pitting corrosion rate, approximately 30 mm/y (1,200 mpy), are considered to be unexpectedly high amounts of chloride ions in the produced well fluids, settling of the produced water under low flow conditions, high condensate/water ratio, inadequate inhibition and pigging, and insufficient monitoring programs. Corrosion mechanisms in sour gas gathering systems with significant CO{sub 2} concentration were reviewed. Preliminary findings pointed to CO{sub 2} partial pressure, not H{sub 2}S, as a main corrosion rate determining factor. The steps taken to prevent similar future incidents were also reviewed.

• OSTI ID: 268173
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALBERTA
CARBON DIOXIDE
CHLORIDES
CORROSION INHIBITORS
CORROSION PRODUCTS
CORROSION PROTECTION
CORROSIVE EFFECTS
DESIGN
FAILURE MODE ANALYSIS
HYDROGEN SULFIDES
IRON SULFIDES
LEAKS
NATURAL GAS DISTRIBUTION SYSTEMS
NATURAL GAS WELLS
PITTING CORROSION
PROTECTIVE COATINGS
REPAIR
RESERVOIR FLUIDS