Limitations in using pulsed rectifiers for well casing cathodic protection

Conference · Wed Nov 01 04:00:00 EST 1995

OSTI ID:124411

Dabkowski, J ^[1]

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1. Electro Sciences, Inc., Crystal Lake, IL (United States)

Due to earth propagation losses the rectifier current pulses suffer considerable waveform deterioration as the penetration depth increases. Hence, cathodic protection benefits attributable to the use of a pulsed rectifier will not be attainable below a certain depth which is a function of the pulse characteristics and the soil resistivity. In this paper a hypothetical 3,000 meter length well casing is modeled as a distributed lossy electrical transmission line. It is shown that below a depth of 300 to 500 meters, the higher frequency content of the pulse is severely attenuated. The cathodic protection process at these and increased depths, therefore, will not differ significantly from that obtained with a non-pulsed dc rectifier.

• OSTI ID: 124411
• Report Number(s): CONF-950304--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
CATHODIC PROTECTION
CURRENT DENSITY
ELECTRIC CONDUCTIVITY
FOURIER ANALYSIS
FREQUENCY ANALYSIS
MATHEMATICAL MODELS
SOILS
WAVE FORMS
WELL CASINGS