抗220 ℃高温两性离子聚合物降黏剂的制备与性能

Preparation and Evaluation of Viscosity Reducer for High Temperature Zwitterionic Polymer Resistant to 220 ℃

潘丽娟 程仲富 方俊伟 方裕燕 温建泰 吕军贤

PAN Lijuan CHENG Zhongfu FANG Junwei FANG Yuyan WEN Jiantai LYU Junxian

针对当前高温高密度水基钻井液流变性调控难题，基于分子结构优化设计和单体优选，制备了新型抗高温两性离子聚合物降黏剂 HP-THIN。通过正交实验与单因素实验相结合的方法，对 HP-THIN 的制备条件进行了优化。采用红外光谱仪、乌氏黏度计和热重分析仪等分别对HP-THIN 的分子结构、热稳定性以及相对分子质量进行表征和测定，研究了HP-THIN 在220 ℃超高温条件下对淡水浆、盐水浆、含钙浆和高密度复合盐水浆等不同类型钻井液基浆的降黏性能。在室温下，测试了HP-THIN 对基浆黏土颗粒吸附能力、Zeta 电位和粒径的影响，并与国内外同类产品（Polythin 和xy-27）进行了对比。结果表明，合成降黏剂HP-THIN 的反应温度为60 ℃，反应时间为 3 h，引发剂用量和链转移剂用量均为反应单体总量的 1%，单体总质量分数为 30%；单体AM、AA、AMPS、 PTM物质的量比为1.9∶7.5∶2.1∶1。该聚合物的分子结构中含有设计官能团，其黏均相对分子质量约为 8211，且具有较好的热稳定性。220 ℃老化后，HP-THIN 在最优加量（0.3%）下对淡水基浆、盐水基浆、含钙基浆和高密度复合盐水基浆的降黏率分别达86%、72%、73%和51%，HP-THIN 对不同类型钻井液基浆的高温降黏效果均优于国内外同类产品，相对于xy-27 和Polythin，降黏剂HP-THIN 对基浆黏土吸附能力强、Zeta 电位绝对值大、黏土颗粒尺寸小，可以更好地消除黏土颗粒间网状结构，降低钻井液黏度，具有良好的应用前景。

In addressing the persistent challenge of rheological control in high-temperature and high-density water-based drilling fluids（WBDFs），a new high-temperature zwitterionic polymer viscosity reducer（HP-THIN）was prepared based on molecular structure optimization design and monomer optimization using orthogonal experiments and single-factor experiments. The molecular structure，thermal stability and relative molecular weight of HP-THIN were characterized and determined by infrared spectroscopy，Ulrich viscometer，and thermogravimetric analysis. The viscosity-reducing ability of HP-THIN on different types of drilling muds such as freshwater mud，salt-containing mud，calcium-containing mud，and high-density composite salt-containing mud was investigated at the temperature of 220 ℃. The effects of HP-THIN on adsorption capacity，zeta potential，and particle size of base-mud clay were tested at ambient temperature and compared with similar commercial viscosity reducers Polythin and xy-27. The results showed that，the optimal reaction recipe of the HP-THIN was as follows，the reaction temperature was 60 ℃ ，thereaction time was 3 h，the amount of initiator and chain transfer agent was 1%（based on the total amount of monomers），and the total mass fraction of the monomer was 30% and the molar ratio of AM，AA，AMPS and PTM was 1.9∶7.5∶2.1∶1. The viscosity-average relative molecular weight of the obtained HP-THIN was about 8211，and the HP-THIN exhibited good thermal stability. After aging at the temperature of 220 ℃ ，the viscosity reduction rates of HP-THIN at the optimal dosage of 0.3% on freshwater-based mud，salt-water-based mud，calcium-containing base mud，and high-density composite salt-water-based mud reached 86%，72%，73%，51%，respectively. Compared to xy-27 and Polythin，HP-THIN demonstrated better high-temperature viscosity reduction effect in all different types of drilling fluid base mud due to its strong adsorption capacity with clay platelets， large absolute value of zeta potential，which was conducive to unentangling the complex polymer network structure between clay particles，significantly decreasing the viscosity of the drilling fluid，showing good application prospects.

10.19346/j.cnki.1000-4092.2024.02.001