Cristin-resultat-ID: 1832221
Sist endret: 22. september 2020 15:52
NVI-rapporteringsår: 2020
Resultat
Vitenskapelig artikkel
2020

Under Deposit Corrosion Testing under Inhibited and pH-stabilized Conditions

Bidragsytere:
  • Attila Palencsar og
  • Conchita Mendez

Tidsskrift

International Corrosion Conference Series
ISSN 0361-4409
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2020
Volum: 2020-June
Artikkelnummer: 14941

Beskrivelse Beskrivelse

Tittel

Under Deposit Corrosion Testing under Inhibited and pH-stabilized Conditions

Sammendrag

The risk of under deposit corrosion (UDC) in oil and gas pipelines where accumulation of solids can be expected is of key importance when CO2 corrosion mitigation strategies are assessed and qualified. In this work the authors present the results of a laboratory study aimed at evaluating the susceptibility for UDC when using either corrosion inhibitor (CI) or pH stabilization under field-relevant conditions, including a basic assessment of inhibitor adsorption on sand. The tests were performed at ambient pressure in jacketed glass cells with a specially designed specimen holder and lid allowing in-situ deposition of a sand layer with a pre-defined thickness. The specimen assemblies comprised three carbon steel coupons, of which two were covered with sand. Galvanic coupling was established between one covered and the non-covered coupons. The behavior of the specimens was monitored electrochemically by continuous measurement of the galvanic current between the coupled specimens as well as regular linear polarization resistance measurements. A parametric study was conducted including temperature, CO2 partial pressure, type of corrosion control chemical, solution chemistry, sand layer thickness and deposition scenario. Inhibition was more effective when established before a sand layer got deposited. When sand was deposited first there was a delay and a reduction in inhibitor efficiency; pH stabilization was shown not to be as effective as inhibition under the test conditions. Galvanic effects increased the risk of both general and localized corrosion: underneath the sand deposit the coupon not galvanically coupled appeared better protected than the one galvanically coupled. Sand layer thickness did not have a significant effect in these tests. It can be noted, however, that sand may impede the CI from reaching maximum efficiency, regular maintenance pigging would therefore be advised. The inhibitor adsorption study confirmed that sand consumes CI by adsorption and this effect was pH dependent for the tested formulation.

Bidragsytere

Iozsef Attila Palencsar

Bidragsyterens navn vises på dette resultatet som Attila Palencsar
  • Tilknyttet:
    Forfatter
    ved Korrosjonsteknologi ved Institutt for energiteknikk

Conchita Mendez

  • Tilknyttet:
    Forfatter
    ved USA
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