耐高温聚乙醇酸缓速酸的制备与性能评价

Preparation and Evaluation of High Temperature Resistant PGA Retarded Acid

葛一卓 赵文娜 张丛 孙增增 徐辰雨 陈明贵

GE Yizhuo ZHAOWenna ZHANG Cong SUN Zengzeng XU Chenyu CHEN Minggui

针对现有常规酸液增产体系高温稳定性较差、酸岩反应速率过快且破乳困难的问题，以聚乙醇酸流体为酸 液内相、柴油为外相，并加入适当的表面活性剂和其他添加剂制备了一种新型PGA缓速酸体系，评价了该缓速酸 体系的稳定性、抗剪切性、产酸能力、溶蚀性。结果表明，优化的PGA 缓速酸在90 ℃时可保持76 h 不破乳， 130 ℃时3 h可产生7.91 mol/L的H+，持续反应时至多可生成9 mol/L以上的H+；130 ℃时剪切120 min后表观黏度 为31.22 mPa·s，150 ℃时为28.4 mPa·s，均符合行业标准。130 ℃时体系对岩心的静态缓速率分别为同浓度土酸 缓速酸和多氢酸缓速酸的2.7倍和2.1倍。PGA缓速酸与岩心的动态反应速率与同浓度的多氢酸缓速酸相比可降 低一个数量级，与土酸缓速酸相比可降低两个数量级。PGA缓速酸对N80钢片的静态腐蚀率仅为3.453 g/（m2·h）。 PGA缓速酸的缓速性能良好，对金属的腐蚀性弱，且最终降解生成物对环境无害，符合现场工艺要求，具有良好 的可持续发展前景。

The conventional acid fluid stimulation system has inferior high-temperature stability，fast acid rock reaction rate and problematic demulsification. To solve the mentioned problems，a high temperature resistant PGA retarded acid was prepared using polyglycolic acid fluid as the inner phase acid fluid and diesel oil as the outer phase，and adding appropriate surfactants and other additives. The properties of the system，including the stability，shear resistance，acid production capacity，dissolution，were evaluated. The results showed that the optimized PGA retarded acid could remain emulsified state for 76 h at the temperature of 90 ℃. The system could produce 7.91 mol/L H+ within 3 h at the temperature of 130 ℃，and more than 9 mol/L H+ at continuous reaction. The final apparent viscosity of the system under sheared for 120 min was 31.22 mPa?s and 28.4 mPa?s at the temperature of 130 ℃ and 150 ℃ ，respectively，which conformed to the requirements of the national standard. The static retarded rate of the system to the core was 2.7 times and 2.1 times higher than that of the same concentration of the mud acid and the multiple hydrogen acid system，respectively. In acid-rock reaction experiments，the system could reduce the acid reaction rate by one or two orders of magnitude compared with the multiple hydrogen acid and mud acid system. the static corrosion rate of the system to N80 steel slice was only 3.453 g/（m2?h），which was lower than the standard value. PDA retarded acid exhibited well slow-release performance and weak corrosion，moreover，the degradation products was harmless，which met the requirements of filed processes and had good prospects for sustainable development.

10.19346/j.cnki.1000-4092.2023.03.003