耐高温油井水泥缓凝剂SCR180L 的合成及评价

针对深井、超深井、长封固段固井中大温差下水泥浆顶部强度发展缓慢或超缓凝的难题，以2- 丙烯酰胺基-2- 甲基丙磺酸（AMPS）、N- 乙烯基吡咯烷酮（NVP）和衣康酸（IA）为原料开发了新型高温缓凝剂SCR180L，并用红外光谱对共聚物的结构进行了表征。室内研究表明，SCR180L 可满足循环温度范围为70~180 ℃的固井需求；100 ℃、50 MPa 下，加入0.9%~1.8%SCR180L 的水泥浆稠化时间延长到127~331 min；150 ℃、70 MPa 下，加入2.7%~3.6%SCR180L 的水泥浆稠化时间延长到214~409 min，且随缓凝剂的加量增加而有规律的延长；温差70 ℃条件下水泥浆强度发展良好，24 h 水泥石强度大于14 MPa；缓凝剂抗盐能力可达到18%。现场应用结果表明，缓凝剂SCR180L 耐温性能好，温度适应范围广，对水泥石抗压强度的影响不明显，可以满足深井、超深井及长封固段、大温差固井的应用需求。

Synthesis and assessment of heat-resistant cement retardant SCR180L for oil producers

Slow development of strength or super retarding may occur at top of cement slurry under large temperature difference during cementing of deep well, super-deep well, and long cementing intervals. To address these problems, an innovative heat-resistant retardant SCR180L was developed by using 2-Acrylamido-2-Methylpropane (AMPS), N-vinylpyrrolidone (NVP) and itaconic acid (IA) as raw materials. In addition, infrared spectrum was used to characterize structure of the co-polymer. Lab test showed that SCR180L can satisfy demands of cementing operations with circulation temperature of 70-180 ℃. Under 100 ℃ and 50 MPa, the thickening time of cement slurry with 0.9%-1.8% SCR180L is prolonged to 127-331 min. Under 150 ℃ and 70 MPa, the thickening time of cement slurry with 2.7%-3.6% SCR180L is further prolonged to 214-409 min. The more retardants added, the longer thickening time can be observed. Under temperature difference of 70 ℃, favorable growth of cement slurry strength is observed, with the cement strength at 24 h over 14 MPa. The retardant displayed high salinity resistance up to 18%. Field applications reveal that SCR180L has outstanding heat resistance and is applicable for a wide range of temperatures. With insignificant impacts on compression strength of the cement, the innovative retardant can satisfy demands for cementing operations in deep wells, super-deep wells, and long cementing intervals where large temperature difference may exist