PREDICTING GALVANIC CO_2 CORROSION IN OIL AND GAS PRODUCTION SYSTEMS

摘要

Some oil and gas production systems have critical components (e.g. manifolds, tees, bends, valves) made out of or internally clad with corrosion resistant alloys for protecting against specific degradation mechanisms. In this work, finite element analyses and potentiodynamic curves generated with a mechanistic CO_2 corrosion model were used to quantify the threat of galvanically enhanced corrosion on different carbon steel components partially clad with Alloy 625. Under the conditions evaluated, uninhibited corrosion rates of carbon steel piping were shown to nearly double near the Alloy 625 interface. The galvanic currents were shown to decrease exponentially with the distance from the carbon steel-Alloy 625 interface, reaching negligible values after 1.5 times the internal diameter.