| Coiled Tubing is a whole root non-threaded tube wrapped around the drum,which can be continued for up to or out from the well.Nowadays,Coiled Tubing Technology has become an increasingly sophisticated new technology in the current oil and gas exploration field.It was widely used in oil and gas exploration and development.However,the majority of oil and gas fields facing the sulfide corrosion to enhance the situation in our country.Therefore,it is interesting to explore and study the material in coiled tubing in the sulfur hydrogen induced cracking;sulfide stress corrosion cracking and corrosion ditch their production and application,and after practice to take appropriate measures to reduce and prevent catastrophic accidents have a positive meaning.In this work,experiments had been carried out under the American Association of Corrosion Engineers NACE Standard TM0284-2003?Tube,pressure vessel steel resistance to hydrogen induced cracking of steel performance evaluation of the experimental method?,with reference to national standard GB/T 9711.3-2005?Oil and natural gas industries steel-Technical delivery conditions for the third part:C-class pipe?.American Association of Corrosion Engineers according to NACE Standard TM0284-2003,respectively,of base metal and weld samples.The sulfide stress corrosion cracking and corrosion behavior of trench of coiled tubing in the sulfide medium under hydrogen induced cracking had been investigated by using the microstructure of welded joints observed morphology.The fracture surface and the fracture elements had been studied by using scanning electron microscopy(SEM)and the energy spectrometer(EDS)analysis.The fracture mechanism had been analyzed from environmental factors,material organization,and the chemical composition.The results indicated that:the production of GC of Baoji Petroleum Steel Pipe Co.,Ltd coiled tubing and coiled tubing imported JK were not sensitive to the hydrogen-induced cracking,hydrogen induced cracking resistance capacity of both to meet the standard requirements,with a strong resistance to hydrogen induced cracking performance.The wide of weld corrosion groove of imported Coiled Tubing JK was narrow,and the wide of GC groove pipe weld corrosion was large.The depth of corrosion of two kinds of welded pipe trench were the same,the weld corrosion depth was 1.2mm,base metal corrosion depth is 1mm.Ditch erosion factor was 1.2,the two weld pipe corrosion were not sensitive to the ditch.The results of sulfide stress corrosion cracking tests indicated that the cracks can be observed in JK,GC material at 72%?s,80%?s,90%?s conditions,the base material at longitudinal,transverse direction and the transverse direction in weld cracks.The elements in fracture surface the component analyzed shown that the corrosion surface were mainly the FeS and with Fe,O,S.Mean while,we can found that the higher levels of FeS were the region of cracks began,in the final stage of crack fracture,FeS content was low.O elements mainly from the iron oxide sample cleaning process.The results of bent experiments indicated that the bending part of no new cracks,also found no crack,no more breakage.It can be included that JK and GC pipe were the resistant to sulfide stress corrosion cracking corrosion. |
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