Corrosion Cause Analysis And Corrosion Inhibitor Development Of Water Injection Pipeline In Heishui Oilfield

With the increase of oilfield injection water development scale and the increase of injection water pipeline using time, Heshui oilfield gathering for waterflood system corrosion problems appear sharply increase trend in recent years, and the problem of corrosion prevention and treatment have must be settled as soon as possible. For effective prevention and control of corrosion, understand the reason and regularity of the corrosion of injection water pipeline, ensure the safety of the Heshui oilfield injection water pipeline work continuously. Aiming at these problems, this paper has carried out systematic research in this respect, and obtained the following results:(1) Through detecting of injection water and corrosion products, analyzed the corrosion and corrosion products of the ingredients, The detecting and analysis results show that the corrosion of dissolved oxygen and CO2 corrosion is the main reason for corrosion of injection water pipeline. A large number of Cl- in the formation of pitting has very significant effect At the same time, Ca2+\Mg2+\bacteria and sulfide will also have a weak corrosion effects on its.(2) On the basis of the above,chose four commonly used imidazoline corrosion inhibitor, the evaluation of corrosion inhibitor experimental results show that the four primary corrosion inhibitor for the Heshui oilfield water injection pipeline has certain corrosion inhibition effect. However, IML-2 showed best inhibition efficiency. Based on the corrosion behavior and mechanism of the quantum chemical calculation results show that imidazoline molecules on the metal surface is not only a single physical adsorption, but a combination of physical adsorption and chemical adsorption, in addition, the reaction active sites of these imidazoline molecules were focused on the five-membered heterocyclic ring and hydrophilic branched-chain.(3) Under the guide of IML-2 which possessed best corrosion inhibition in evaluation experiments, synthesis of a kind of green environmental protection imidazoline quaternary ammonium salt named CIH,which is widely used in the oil field pipeline anticorrosion. And with CIH\SPC and TDAP distribution, get a new kind of compound corrosion inhibitor named NU. On the foundation of single factor analysis, the optimal concentration distributed ratio of NU new inhibitor by virtue of response surface methodology was determined as follows: CcIH:CSPC:CTDAP=162.00mg/L:80.02mg/L:59.93mg/L.In the condition of such optimal concentration, the predicted ηJ and ηD could reach 92.2942% and 93.4726%, respectively. Repeated verification experiment results are stable. At the same time, the verification test for the corrosion inhibition of this inhibitor under optimal concentration was conducted in order to check the consistency between the predicted and actual values. The accuracy and reliability of the optimal condition obtained from above experiments were proved. And the new corrosion inhibitor has good inhibition effect for Heshui oilfield water injection pipeline corrosion.