抗高温油井水泥降失水剂的合成及性能评价

Synthesis and Performance Evaluation of High Temperature Resistant Fluid Loss Reducer for Oil Well Cement

李晓岚 国安平 李韶利 马小龙 孙 举

LI Xiao-Lan GUO An-Ping LI Shao-Li MA Xiao-Long SUN Ju

以丙烯酰胺（AM）、2-丙烯酰胺基-2-甲基丙磺酸（AMPS）和N-乙烯基吡咯烷酮（NVP）合成了三元共聚物油井水泥降失水剂，考察了单体质量分数、单体配比对聚合物降失水性能的影响。在75℃、6.9 MPa下，含三元共聚物的水泥浆失水量随单体质量分数的增加先降低后增加，随AMPS加量的增加而增大，随NVP加量的增加变化较小。最佳合成条件为：单体质量分数12%，AM、AMPS、NVP摩尔比8.5:1.0:0.5，反应温度70℃，反应时间5 h，引发剂加量0.7%，pH值为12。当降失水剂加量为4.2%时，水泥浆在160℃时的失水量为60 mL，浆体的初始稠度为14 Bc，稳定性好，水泥石强度发展快。

Terpolymer of fluid loss reducer for oil well cement was synthesized by acrylamide (AM), 2-acrylamido-2-methyl-propane sulfonic acid (AMPS) and N-vinyl pyrrolidone (NVP). The effects of the monomer concentration, monomer ratio on the fluid loss performance of polymer were investigated. Under the condition of 75℃ and 6.9 MPa, the API fluid loss of the cement slurry first decreased and then increased with increasing monomer content, increased with increasing AMPS dosage, and changed slightly with increasing NVP dosage. The optimum reaction condition was obtained as follows: 12% monomer mass fraction, 8.5:1.0:0.5 monomer mole ratio of AM:AMPS:NVP, 70℃ reaction temperature, 5 h reaction time, 0.7% initiator and 12 pH value. The fluid loss of cement mortar containing 4.2% (BWOC) polymer at 160℃ was of 60 mL with good slurry stability, 14 Bc initial consistency and rapid development of cement stone strength.