酸压用微膨胀可降解凝胶暂堵剂的研制与应用

Development and Application of Degradable Gel Temporary Plugging Agent with Micro-expansion for Acid Fracturing

吴文川 于小荣 王涛 董国峰 杨欢 苏高申

WUWenchuan YU Xiaorong WANG Tao DONG Guofeng YANG Huan SU Gaoshen

针对碳酸盐岩储层转向酸压所用暂堵剂耐酸性差、解堵工艺复杂、成本高的问题，以自制的季铵酯（JD-1） 为交联剂，采用水溶液自由基聚合法制备了一种酸压用微膨胀可降解凝胶暂堵剂（WDS）。评价了WDS的降解 性能、封堵性能及对储层的伤害性，并在HY井进行了现场施工应用。结果表明，WDS在HCl溶液或不同矿化度 水溶液中呈现先微膨胀后降解的变化规律。当温度由70 ℃提高到120 ℃，WDS在10% HCl溶液中完全降解的 时间由78 h 缩短为45 h。当HCl 质量分数由3%增至20%时，90 ℃下WDS完全降解的时间由75 h 缩短为48 h。 盐浓度越大，WDS完全降解的时间越长。岩心驱替实验结果表明，WDS注入量越大、裂缝宽度越窄，暂堵压力峰 值越大，达到最高暂堵压力的时间越短。WDS对岩心的伤害性较小，岩心渗透率恢复值可达到90%以上。在现 场应用中使用WDS后，油压上升了10 MPa，暂堵转向效果显著。

In view of the problems of poor acid resistance，complicated removal process and high cost of temporary plugging agent used in acid fracturing of carbonate reservoir，a kind of degradable gel temporary plugging agent with micro-expansion（WDS）for acid fracturing was prepared through aqueous radical polymerization method by using self-made quaternary ammonium ester （JD-1）as cross-linking agent. The degradation performance，plugging performance and reservoir damage of WDS were studied. Finally it was applied in HY well. The results showed that WDS was first micro-expansion and then degradation in HCl solution or aqueous solutions with different salinity. The complete degradation time of WDS in 10% HCl solution reduced from 78 h to 45 h when the temperature rose from 70 ℃ to 120 ℃ . When the mass fraction of HCl increased from 3% to 20%，the complete degradation time of WDS at 90 ℃ shortened from 75 h to 48 h. The higher the salt concentration，the longer the complete degradation time of WDS was. According to the results of core displacement experiment，with increasing injection of WDS and decreasing fracture width，the peak value of temporary plugging pressure increased，while the time reaching the maximum temporary plugging pressure reduced. In addition，WDS was less harmful to the core. The permeability recovery value of core was more than 90%. After using WDS in field application，the oil pressure was increased by 10 MPa，indicating remarkable effect of temporary plugging.

10.19346/j.cnki.1000-4092.2023.01.008