针对姬塬油田长 X储层近年来注水井注水压力高、酸化效果差、多次措施无效的问题，研发了一种螯合酸酸液体系，形成了“不动管柱+在线注入”的主体酸化工艺技术，实现了“一步”代“多步”、高效、快速酸化作业。考察了螯合酸的缓速性能、螯合性能、沉淀抑制性和腐蚀性，并进行了岩心流动实验和现场应用。室内酸液性能评价结果表明，与常规土酸对比，螯合酸具有缓速性好、腐蚀慢、螯合能力强、抑制沉淀能力强等特点，可确保施工工艺，减少了起下管柱、残酸返排等步骤。室内岩心模拟实验结果表明，螯合酸可有效提高岩心渗透率和孔隙度，同时避免了常规土酸生成二次沉淀堵塞孔喉的缺点。矿场试验结果表明，该技术可有效提高单井日注水量，降低注水压力，缩短施工用时，38口欠注井平均施工用时 10 h，平均单井注水压力下降 1.7 MPa，平均单井日增注13 m3，累计增注 311695 m3。 图 3表 4参 10
Aimed at the problems of the Jiyuan oilfield chang X reservoir in recent years，such as high pressure，water injected difficulty and invalid measure repeated，the chelating acid system was developed and "without lifting pipe string + online injection" main construction acidizing technology was formed，which implemented that "one-step" replaced " multistep" and acidized efficiently and quickly. The performance of the retardance，chelation，precipitation inhibition and corrosion was measured compared to that of the conventional mud acid，the indoor simulation experiments and field test was carried out. The acidizing evaluation laboratory test results showed that compared with the conventional mud acid，the chelating acid system was characteristic of low corrosion rate，fine ability to retard and chelate，ability to prevent secondary precipitation of ferric ion effectively，which reduced many steps such as tripping pipe string and residual acid cleanup. Indoor simulation experiments showed that the chelating acid could enhance permeability and porosity of core effectively，at the same time，avoid pore throat block which was caused by secondary precipitation generated by conventional soil acid. Field test results of 38 high pressure water wells in Jiyuan oilfield indicated that the technology could improve injection flow rate，reduce injection pressure，shorten acidizing process time，and average work time of 38 wells was 10 h，the average injection pressure reduced by 1.7 MPa，the average daily injection increased by 13 m3，and the cumulative water injection increased by 311695 m3.