低聚合度PDMDAAC合成及防膨性能

RESEARCH ON SYNTHESIS AND ANTISWELLING PROPERTY OF PDMDAAC WITH LOW POLYMERIZED DEGREE

低聚合度PDMDAAC具有防膨性能好、岩心伤害率低的特点.为进一步探讨其性能,以甲酸钾为链转移剂,采用过硫酸铵-亚硫酸氢钠氧化还原引发体系,研究了低聚合度PDMDAAC的聚合规律.同时采用控制变量法,研究了聚合温度、单体起始质量分数、链转移剂用量、引发剂用量、反应时间、聚合体系pH值对聚合物特性黏数和单体转化率的影响规律.结果表明：相对分子质量为1 900的低聚合度PDMDAAC具有很强的抑制黏土水化膨胀能力,质量分数为4.0%时,防膨率可达到90%以上.低聚合度PDMDAAC对低渗岩心的伤害较小,岩心伤害率为17.85%,对于低渗油层有较好的适应性.

PDMDAAC with low polymerized degree is characterized by favorable antiswelling property and low damage rate to rock core. This paper studies the polymerization rule of PDMDAAC with low polymerized degree by using potassium formate as the chain-transfer agent and ammonium persulfate-sodium bisulfite redox system as the initiator. The factors, such as polymerization temperature, monomer initial mass fraction, dosage of chain-transfer agent, dosage of initiator, reaction time and pH value of polymerization system, which affect the intrinsic viscosity number and monomer conversion rate of PDMDAAC, are investigated with the control variable method. The PDMDAAC with 1 900 relative molecular weights has a strong ability to repress the hydration and expansion of clay. When the mass fraction is 4.0% , the antis-welling rate is more than 90%. Damage of PDMDAAC with low polymerized degree to the low-permeability core is low and the damage rate of the core is only 17.85% , which means better adaptability for the low-permeability oil layers.