Corrosion Inhibitor Of Well Killing Fluid For Expanding Gas Deep Well In Xujia Weizi Oil Field

During the development of natural gas in oil field,carbon dioxide is a serious problem in the corrosion of all kinds of equipment.The corrosion of acid gas to the gas system has become an important problem in the rapid development of gas field.Aiming at the above problems,this paper first studied the corrosion rules of different pressure well liquid systems.Research results show that the N80 steel in co2 condition of well killing fluid system,the corrosion rate will increase as the density of the system and slow,and increased with the temperature increasing,after more than 80 degrees Celsius temperature,corrosion rate significantly faster.The corrosion rate of N80 steel will be accelerated after the carbon dioxide enters into the liquid system.The influence of the liquid system density on the corrosion rate of 13Cr steel was small,and the temperature was sensitive.13 cr in KCl well killing fluid system,prone to pitting corrosion,but in the rest of the two systems of pitting corrosion degree is weak,in addition,the invasion of carbon dioxide,will exacerbate 13 cr steel in KCl degree of corrosion in the kill fluid system,but for the rest of two kinds of drilling fluid system,will not cause great influence to the degree of corrosion.On this basis,the corrosion rate of N80 steel and 13Cr steel in three high ratio pressure Wells was compared,and the corrosive order was obtained:KCl pressure well,>NaN03,and sodium bb1 formate.On this basis,10 kinds of corrosion inhibitors and the sustained release effect of the complex system were selected for the KCl-N80 steel system with the most serious corrosion conditions.The study found that in potassium silicate and polyacrylamide carried out in accordance with the proportion of 1:1 complex after the match,when using slow-release effect is best,at 90%,at the same time,this system in the case of carbon dioxide also can have good slow release effect.The corrosion rate of N80 steel can be reduced to 0.075mm/a under the condition of 1%-2%corrosion inhibitor concentration.Using wire beam electrode for N80 steel in KCl well killing fluid system of thought after the sensitive degree of local corrosion,only using potassium silicate or polyacrylamide will exacerbate the local corrosion of steel,and after the two distribution,can be a good impact on the local corrosion inhibition.