For Expanding Gas Deep Well Corrosion Inhibitor Research Of Well Killing Fluid

In the process of gas drilling in daqing oilfield,especially CO₂ corrosion problem of mining equipment.Sour gas corrosion problems are important factors restricting the development of safe and efficient gas field,can effectively solve the problem of corrosion direct relationship between the gas field development and people's life safety.In order to solve this problem,this article first to different corrosion law of well killing fluid system was studied,the results found N80 steel in does not contain three kinds of well killing fluid of CO₂,the corrosion rate decreases with the increase of well killing fluid density,increases with the rise of temperature and,in particular a sharp rise in temperature over 80 ? after corrosion.After CO₂ invaded the well killing fluid,intensifying the corrosion of N80.13 cr corrosion of stainless steel pressure well liquid density is affected,mainly with the rising of temperature gradually increased.13 cr steel in KCl pressure well liq uid,are prone to corrosion,and in the other two middle of well killing fluid corrosion is not obvious.Additional CO₂ intrusion can accelerate 13 cr steel corrosion in the KCl pressure well liquid in sodium nitrate well killing fluid,formate the impact of well killing fluid.And comprehensive comparison,13 cr stainless steel N80 steel corrosion rate in the three kinds of high pressure well liquid,can obtain the corrosive order: KCl pressure well liquid > > Na NO3 pressure well liquid sodium formate well killing fluid.Against corrosion is most serious after KCl-N80 steel of well killing fluid system,single and compound with the 10 kinds of corrosion inhibitors for assessment of N80 steel corrosion effect,found that potassium silicate,sea slowly,pol yacrylamide,potassium thiocyanate has certain corrosion effect,especially potassium silicate and polyacrylamide with 1:1 distribution when using,the corrosion effect can reach more than 90%,the recipe when CO₂ is also has very good corrosion effect,the best concentration of corrosion inhibitor to join for 1 2%,the corrosion rate of N80 can control below 0.075 mm/a,and using wire beam electrode N80 steel were studied in KCl of local corrosion sensitivity of well killing fluid.The single use of potassium silicate and polyacrylamide could promote the local corrosion,and the composite use,is has good inhibition to local corrosion.