Introduction of Corrosion resistant oil well seamless steel pipe

Oil Wells and site gas Wells steel pipes involve the drill pipe for mining, effectively wall defense pipe inserted within the nicely to reduce development collapse and pipeline program hanged inside of the wall defense tube for manufacturing.nBased on stability issues, oil perfectly pipe normally adopts seamless metal pipe.nnAs a consequence of the oil perfectly and gas effectively mining depth deepening calendar year by yr, these types of substantial energy oil nicely pipes as N80 (generate strength 551 MPa grade) and P110 (produce power 758 MPa) are produced, these pipes have attained the American petroleum institute expectations.nnHowever, the sulfide stress cracking accident took place in the 50s in Canada, so sulfide corrosive ecosystem sulfide pressure cracking of high strength metal aroused people's issue.nSulfide pressure cracking of very low alloy steel is a kind of variety of hydrogen embrittlement, the creation fluid with the program of hydrogen sulfide inhibits corrosion response in the system of hydrogen manufactured by dissipation, to invade the significantly elevated the amount of hydrogen in steel.nnThe higher the power of steel, the greater the sensitivity of sulfide worry cracking, so excellent to sulfide stress cracking resistance of higher toughness metal for development.nThe sulfide strain cracking resistance of steel is related with the microstructure of steel.nFrom martensite section organization perspective demonstrates the following measures is successful: adding Nb and quenching tempering warmth cure can type great grain composition Minimize the intergranular segregation things these kinds of as P and Mn can prevent the grain boundary cracks Raising tempering temperature can lower the internal strain, etc.nnnSince the 60s have formulated resistance to sulfide strain cracking of very low alloy oil nicely drill pipe, and has manufactured steady improvement.nIn the deep well, thanks to the significant bottom gap temperature (5000m class well, downhole temperature about 250 e), so the corrosion setting is incredibly really serious.nIn oil Wells in critical corrosion atmosphere, usually to inject metal rust preventer protection, but no make any difference technically, or from an financial issue of watch, anticorrosive agent application is really complicated, hence produced suited for all types of corrosive setting, without having injecting antifushiji the corrosion resistance of alloy metal.nnFrom the standpoint of corrosion resistance, corrosion resistant alloy metal can be roughly divided into system of martensite stainless metal, duplex stainless metal and austenite procedure substantial Ni alloy a few forms. The CO2 corrosion atmosphere is normally referred to as low sulfur corrosion surroundings.nCO2 and H2S manufacturing fluid with jointly, but can type weak acid immediately after CO2 dissolved in h2o, can be used as intake owing to metal corrosion reaction of the resource of H + ions, so as opposed with the similar acid aqueous answer pH, the corrosion charge of carbon metal.nnTo decrease less than the ecosystem of CO2 corrosion fee, powerful solution is to incorporate Cr, now very good to underneath the surroundings of CO2 corrosion resistance and financial system of 13 Cr metal (AISI420) desire increased swiftly.nHowever, mainly because of 13 Cr metal under the temperature of much more than 150e, corrosion pace will enhance, and the traces of H2S ecosystem with sulfide stress cracking sensitivity, consequently produced a new style of thirteen Cr steel, namely by lowering the content of C, inhibition of Cr carbide precipitation, making sure powerful total of Cr, which can enhance the software of the critical temperature in CO2 setting.nnIn addition, include the Mo can make in the trace H2S natural environment passivity oxide movie security, inhibition of hydrogen in the steel. In particular under the setting of high temperature, duplex stainless metal containing 22% ~ twenty five% Cr can be made use of.nIn oil Wells and fuel Wells with plenty of H2S, can use the austenite superior Ni alloy with great corrosion resistance.nIts crucial temperature and corrosion resistant alloy aspects of the written content of Mo and W, dependent on the use environment, has designed a Mo and W articles distinctive alloy collection.