Method for assessing electrical resistance of pipeline casings

Technical Report · Fri Dec 01 04:00:00 EST 1989

OSTI ID:6841297

Frazier, M J; Barlo, T J

Gas transmission pipelines are sometimes required to be encased in a larger diameter pipe segment in selected areas, such as under roads or railroad crossings. In time, the casing may become electrically connected to the carrier pipe, either by a metallic short or by an electrolytic path caused by ingress of groundwater through the casing end seals. In the case of a metallic short, the carrier pipe may be shielded from the benefit of the cathodic protection currents. Conventional measurements do not provide an unambiguous indication of the status of the carrier pipe in many situations. This research project was conducted to develop a suitable method. The objectives of the research were: (1) to develop techniques to determine whether the casing and the carrier pipe are effectively isolated from each other or if they are shorted together, and (2) to develop a measurement technique which will allow the degree of cathodic protection of the carrier pipe within an electrolyte-containing annulus region of the casing to be assessed if the casing is not shorted to the carrier pipe.

• Research Organization: Science Applications International Corp., Hoffman Estates, IL (USA)
• Sponsoring Organization: AGA
• OSTI ID: 6841297
• Report Number(s): PR-151-816
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
032000* -- Natural Gas-- Transport
Handling
& Storage
36 MATERIALS SCIENCE
360104 -- Metals & Alloys-- Physical Properties
CATHODIC PROTECTION
COATINGS
CORROSION PROTECTION
DOCUMENT TYPES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROLYTES
MEASURING INSTRUMENTS
MEASURING METHODS
PHYSICAL PROPERTIES
PIPELINES
POLARIZATION
PROGRESS REPORT