高温延迟交联聚丙烯酰胺凝胶堵漏剂的研究

利用热熔胶的热塑性，制备了热熔胶延迟引发剂。基于自由基聚合，以丙烯酰胺、N，N’-亚甲基双丙烯酰胺为单体合成了高温延迟交联聚丙烯酰胺凝胶堵漏剂。利用红外光谱和扫描电镜对高温延迟交联堵漏剂进行了结构表征，并对凝胶的成胶时间、封堵能力和抗温性能进行了测试。实验结果表明，引发剂成功被热熔胶包覆。此外，高温延迟交联堵漏剂性能评价实验表明，相比空白样，其可有效地延迟成胶时间，成胶时间为1～4 h可调；同时，该凝胶还具有优良的封堵性能，高温下可有效封堵4 mm缝宽缝板，承压4.83 MPa以上；凝胶具有良好的抗温能力，150℃热滚96 h后，破胶率仅5%。高温延迟交联凝胶保证了现场地下交联凝胶堵漏施工的顺利进行，可有效封堵裂缝型恶性漏失。

Study on High Temperature Delayed Crosslinking PAM Gel LCM

A hot melt adhesive delayed initiator was developed making use of the thermoplastic property of hot melt adhesive. This delayered initiator was then used to develop a high temperature delayed crosslinking polyacrylamide (PAM) gel lost circulation material (LCM) using acrylamide and N,N'-methylene bisacrylamide as the monomers. The high temperature delayed crosslinking LCM was characterized by IR spectroscopy and SEM, and its gel-forming time, plugging capacity and high temperature resistance were all tested. The experimental results showed that the initiator was successfully coated with the hot melt adhesive. Compared with the blank sample, the high temperature delayed crosslinking LCM can effectively delay the gel forming time, making the gel forming time adjustable between 1 h and 4 h. The LCM has excellent plugging performance, it effectively plugged a fracture of 4 mm at elevated temperatures under 700 psi or higher pressure working on the fracture. The LCM also has high temperature resistance, after hot rolling 5 d at 150℃, only 5% of the gel was broken. This high temperature delayed crosslinking gel LCM can be used to effectively stop severe mud losses to fractured formations.