抗高温超分子降滤失剂的合成及性能评价

针对深井、超深井高温钻井过程中钻井液处理剂耐温能力不足、滤失造壁性能差等问题，以超分子聚合物的聚合理论为基础，以AMPS、AM与N-乙烯基吡咯烷酮（NVP）为单体，合成了一种三元共聚物降滤失剂。通过优化实验确定了最佳合成条件:单体物质的量比AM︰AMPS︰NVP=6︰3︰1，引发剂含量为0.2%，单体总含量为15%，反应温度为50℃，反应时间为4 h。采用红外、热重、TEM对合成产物进行了结构分析，结果表明合成的超分子降滤失剂是由具有特殊功能基团的单体通过自由基聚合而成的，侧链的功能基团通过氢键、亲疏水性、离子键等协同作用形成空间的有序网络结构。这种非共价键的网络结构外界条件变化时，能够迅速改变结构以适应外界条件的变化。此外，分子间强的分子间作用力使超分子降滤失剂具有快速适应环境变化的能力，表现出好的抗温、抗盐和抗钙性。在4%淡水基浆中考察了合成降滤失剂的降滤失性能，合成降滤失剂的抗温性明显优于PAC-LV，抗温高达180℃。 

Synthesis and Evaluation of a High Temperature AMPS/AM/NVP Copolymer Filter Loss Reducer

Filter loss reducers presently in use had poor stability and filtration control ability in drilling deep and ultra-deep wells. To overcome these problems, a terpolymer filter loss reducer has been synthesized in laboratory with 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AM), and N-vinyl pyrrolidone (NVP). The optimum synthesis conditions were as follows:molar ratio of AM:AMPS:NVP=6:3:1, concentration of initiator=0.2%, concentrations of the monomers used was 1.5%, respectively, reaction temperature=50℃, and the reaction time=4 h. Structure analysis of the synthesized product with IR spectroscopy showed that it was a terpolymer, and TEM analysis showed that the synthesized product formed an ordered space network structure in water solution. In a 4% fresh water base drilling fluid, the high temperature stability of the synthesized filter loss reducer was remarkably better than that of PAC-LV; the synthesized filter loss reducer functioned effectively at 180℃.