Research On CO 2 Drive Corrosion Prevention Technology Of Liubei In Jidong Oilfield

Jidong Oilfield in Liubei area carried out CO2 flooding pilot test,has achieved good application effect.It has important reference for large-scale application of CO2 flooding technology in complex fault block reservoirs.In the implementation process,due to the influence of reservoir heterogeneity,dominant seepage channel development and other factors,with the increase of mining time,the CO2 content in the production gas increases continuously,and the CO2 content in some wells is more than 90%.The comprehensive and localized corrosion of oil casing and downhole tools caused by CO2 in water medium had a great influence on the production.In order to ensure the smooth development of CO2 flooding technology,Jidong Oilfield Liubei CO2 flooding corrosion prevention technology needs to be studied.(1)Aiming at the concrete working environment of CO2 injection and production wells in Liubei,through the study of CO2 corrosion mechanism and the indoor simulation experiment under the condition of 22 kettle high temperature and high pressure,the corrosion of five commonly used as rod materials under different temperature,CO2 partial pressure and water content was mastered,for the development of anti-corrosion measures and tubing material selection provides a basis;(2)Through the optimized study of CO2 flooding in single layer,and multi-layer injection column and gas injection supporting tool,the anticorrosive technology suitable for CO2 flooding in Liubei is formed,which meets the requirements of CO2 flooding,corrosion protection and post-operation requirements.(3)Through the wellhead,sucker rod preservative and anti-corrosion scale and other downhole tools,anti-corrosion pump,casing plus corrosion inhibitor,corrosion monitoring technology research,the anti-corrosion column and the anti-corrosion series technology of the oil well are adapted to the CO2 flooding wells in Liubei,which meet the requirements of corrosion prevention of CO2 flooding wells.(4)Field test of the oil rod anti-corrosion,anti-corrosion pump,casing plus corrosion inhibitor,iron ion monitoring,casing corrosion logging was carried out.After the application of anti-corrosion technology,the anti-corrosion efficiency of the oil recovery wells reached 91.2%,and the pump cycle was extended from the previous 276 days to 535 days,and the anti-corrosion effect was achieved.