초록 ▼

Corrosion Under Insulation (CUI) of an insulated iron or other corrosion prone object (1) is detected by taking a sample (8) of the pore fluid from the pores of a permeable insulation layer (2) that covers at least part of the object (1) and analyzing the composition of the sample (8) on the presenc

Corrosion Under Insulation (CUI) of an insulated iron or other corrosion prone object (1) is detected by taking a sample (8) of the pore fluid from the pores of a permeable insulation layer (2) that covers at least part of the object (1) and analyzing the composition of the sample (8) on the presence of any tracer fluid, such as phospines, mercaptans, alcohols, acids, ketones and/or aldehydes emitted or acetic acid and/or butoxyethanol absorbed by any corrosion of the corrosion prone object (1) by a tracer fluid detection sensor (6).

대표청구항 ▼

1. A method for detecting corrosion of an insulated corrosion prone object, which is at least partly covered by a permeable insulation layer with pores containing a pore fluid, wherein the permeable insulation layer is arranged between an outer surface of the corrosion prone object and an inner surf

1. A method for detecting corrosion of an insulated corrosion prone object, which is at least partly covered by a permeable insulation layer with pores containing a pore fluid, wherein the permeable insulation layer is arranged between an outer surface of the corrosion prone object and an inner surface of a protective layer, the method comprising taking a sample of the pore fluid and analyzing the composition of the sample for the presence of any tracer fluid emitted or absorbed by any corrosion of the corrosion prone object, wherein the sample is taken by injecting a sweep fluid through a tracer fluid injection conduit into the pores of the permeable insulation layer and capturing a mixture of the sweep fluid and the pore fluid and any tracer fluid from a fluid excavation conduit through the permeable insulation layer. 2. The method of claim 1, wherein the corrosion prone object comprises rust prone iron, such as carbon steel. 3. The method of claim 2, wherein the tracer fluid comprises phosphines, mercaptans, alcohols, acids, ketones, aldehydes and/or any other chemical composition released during iron oxidation. 4. The method of claim 3, wherein the tracer fluid comprises phosphine (PH3), organophosphine, methylmercaptan (CH4S), methanol (CH4O), acetic acid (C2H4O), acetone (C3H6O) and/or acetaldehyde (C2H5O). 5. The method of claim 4, wherein the tracer fluid comprises organophosphine comprising CH5PO2, known as Methyl Phosphinic Acid or MPA. 6. The method of claim 1, wherein the sweep fluid comprises a reactive rust tracer which reacts with and is therefore absorbed by rust and/or other corrosion products. 7. The method of claim 6, wherein the sweep fluid comprises air, an inert gas and the reactive rust tracer, which comprises acetic acid, phosphoric acid, butoxyethanol, and/or any other reactive rust tracer compound that reacts with rust and/or other corrosion products to provide a quantitative evaluation of the size of a corroded area of the corrosion prone object. 8. The method of claim 1, wherein the protective layer is substantially impermeable. 9. The method of claim 8, wherein the tracer fluid injection conduit is stabbed through the protective layer into the permeable insulation layer. 10. The method of claim 9, wherein the fluid excavation conduit is stabbed through the protective layer into the permeable insulation layer. 11. The method of claim 1, wherein the fluid excavation conduit co-axially surrounds the tracer fluid injection conduit. 12. The method of claim 1, wherein the corrosion prone object is an insulated tubular, which is surrounded by tubular insulation and protective layers and the tracer fluid injection conduit is stabbed near one end of the insulated tubular through the wall of the protective layer into pores of the permeable insulation layer and the fluid excavation conduit is stabbed near another end of the insulated tubular through the wall of the protective layer into the pores of the insulation layer. 13. The method of claim 12, wherein the insulated tubular is a carbon steel oilfield tubular or a carbon steel tubular or vessel in a crude oil and/or gas natural gas processing or oil refinery plant and the method is used for non-intrusive inspection of the tubular on the presence of rust, and the tubular is approved for processing of hydrocarbon fluid if the fluid mixture comprising sweep fluid, pore fluid and any tracer fluid comprises up to a predetermined maximum content of phosphine, mercaptans, alcohols, acids, ketones, aldehydes and/or any other chemical composition released during iron oxidation. 14. The method of claim 13, wherein the fluid excavation conduit comprises a sensor which determines the content of phosphine, MPA, mercaptans, alcohols, acids, ketones, aldehydes and/or another tracer fluid in the fluid mixture. 15. A system for detecting corrosion of a surface of a corrosion prone object, which is at least partly covered by a permeable insulation layer that comprises pores with a pore fluid, the system comprising a protective layer surrounding the corrosion prone object, the permeable insulation layer being arranged between an outer surface of the corrosion prone object and an inner surface of the protective layer, the system further comprising a fluid excavation conduit for capturing a sample of the pore fluid from the permeable insulation layer, a tracer fluid injection conduit for injecting a sweep fluid into the pores of the permeable insulation layer, and means for analyzing the composition of the sample for the presence of any tracer fluid emitted or absorbed by any corrosion of the corrosion prone object.