Aiming at the problems of rapid increase of injection pressure, serious decrease of water injection rate and short validity period after adopting conventional soil acidizing measures in offshore B oilfield, taking well B-2 of this oilfield as the research object, through the analysis of reservoir damage factors, the main reasons of water injection well plugging were found out, including reservoir water sensitivity, unsatisfactory injection water quality, improper plugging and acidizing measures, etc. On this basis, a new type of complex acidizing plug removal technology was developed. Through a large number of laboratory experiments, a new type of complex acidizing plug removal system suitable for water injection wells in this oilfield was optimized with YJS-101 as the main treatment agent, and the comprehensive performance of the system was evaluated. The results show that the system has good corrosion resistance to calcium carbonate and inorganic plugging materials, the corrosion rate is 95.34％ and 90.19％ respectively, while the corrosion rate to natural core powder is only 5.22％; the system has better anti-swelling and corrosion inhibition performance than conventional hydrochloric acid and mud acid; the results of core simulation acid plugging removal experiment show that the new complex acidizing plugging removal system can not only relieve the plugging that has been formed in the core, but also effectively improve the matrix permeability of the core, and play a good effect of acidizing plugging removal.%针对海上B油田注水井注水压力升高过快、注水量严重下降以及采用常规土酸酸化措施后有效期短等问题,以该油田B-2井为研究对象,通过储层伤害因素分析,找出了注水井堵塞的主要原因,包括储层水敏、注入水水质不达标、不适当的调剖及酸化措施等,堵塞原因比较复杂.在此基础之上,开展了新型复合酸化解堵技术研究,通过大量室内实验,以新型复合有机酸YJS-101为主要处理剂,优选出一套适合该油田注水井的新型复合酸化解堵体系,并对体系的综合性能进行了评价.结果表明,该体系对碳酸钙以及现场无机堵塞物具有良好的溶蚀能力,溶蚀率分别为95.34％和90.19％,而对天然岩心粉末的溶蚀率较低,只有5.22％;体系比常规盐酸和土酸具有更好的防膨性能和缓蚀性能;岩心模拟酸化解堵实验结果说明,新型复合酸化解堵体系不仅能够解除岩心内部已经形成的堵塞,还能有效的改善岩心的基质渗透率,起到了良好的酸化解堵效果.
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