Method And Apparatus for Detection of Pitting Corrosion Under Iron Sulfide Deposition

A method for monitoring pitting corrosion of a production tubing in a hydrocarbon well under downhole conditions during a production process using a coupon segment, the method comprising the steps of:

• placing the coupon segment in the hydrocarbon well at a placement depth, wherein the coupon segment is exposed to produced fluids, wherein the coupon segment comprises:
• an outer layer, wherein the outer layer comprises the same metallurgy as the production tubing, wherein the outer layer comprises a known thickness,
• an inner layer, and
• a hollow middle layer, wherein the hollow middle layer comprises a tracer fluid, wherein the tracer fluid is operable to leak from the hollow middle layer into the produced fluids when pitting corrosion penetrates the outer layer;
• operating the production process in the hydrocarbon well such that produced fluids flow through the production tubing to a surface of the hydrocarbon well, and wherein the produced fluids contact the coupon segment such that pitting corrosion occurs on the coupon segment;
• obtaining a sample of the produced fluids at the surface of the hydrocarbon well;
• and
• measuring an amount of the tracer fluid in the sample.