聚乙二醇二丙烯酸酯交联共聚型酸液稠化剂的合成

 以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙烷磺酸(AMPS)为主要单体，以聚乙二醇二丙烯酸酯(PEGDA)为扩链剂，研制了一种注酸时稠化能力强、返排时黏度低的新型酸液稠化剂。通过正交试验，确定了合成AM-AMPS二元共聚物的最优条件为：AM/AMPS的摩尔比为7/3，单体的质量分数为20%，引发剂的加量为125mg/l，引发温度为15℃。在聚合过程中，加入占AM和AMPS单体质量分数7.5×10-6的PEGDA，增粘能力可提高近1倍。酸化过程中，由于PEGDA中的酯基断裂，稠化酸的黏度降低，有利于残酸返排。

A GELLING AGENT CROSSLINKED BY POLYETHYLENE GLYCOL DIACRYLATE ESTER

A new gelling agent was developed by using acrylamide (AM) and 2-acrylamido-2methylpropane sulfonic acid (AMPS) as main monomers, polyethylene glycol diacrylate ester(PEGDA) as chain extender. After addition of this gelling agent, acid can be effectively thichened during injection; while before flowing back, the acid can break down timely to form a low viscosity fluid. By orthogonal experimental design, the optimum reaction conditions for AM-AMPS copolymer were obtained as follows: molar ratio of 7/3 for AM to AMPS, monomer mass fraction of 20%, initiator mass concentration of 125mg/l, initial reaction temperature of 15℃. By adding PEGDA with a mass fraction of 7.5×10-6 into the mixture of AM and AMPS, the ability of the reaction adduct to thicken acid can be improved by nearly one time. For vicious acid formulated by above adduct, its viscosity can be reduced continuously during heat treatment because of the break of ester bond in PEGDA. This behavior will favour the flowing back of spent acid.