油井水泥用聚合物微球膨胀剂的合成与性能

Synthesis and Properties of Polymer Microsphere Expander BCP-3S for Oil Well Cement

为解决固井水窜问题,通过借鉴调剖堵水技术原理,选用丙烯酰胺、2-丙烯酰胺-2-甲基丙磺酸、丙烯酸酯为主要原料制备了粒径为100 nm左右的交联聚合物微球BCP-3S。利用扫描电镜和透射电镜对其微观形态进行观察,开展了聚合物微球水泥浆常规性能评价试验、水泥石膨胀性能测试以及水泥石裂缝自封堵试验。结果表明,聚合物微球膨胀剂BCP-3S具有良好的球形形态,对水泥浆常规性能无不利影响;加入0.6%(BWOC)的BCP-3S后,养护7 d的水泥石膨胀率最高达1.62%,远高于目前在用膨胀剂;水泥石出现裂缝遇到水窜后,BCP-3S可进一步发生膨胀,直径由原来的100 nm左右膨胀为600 nm以上,有效填充和阻塞裂缝,防止水窜发生。目前该技术在大港油田调整井官XX井成功实施,固井一界面胶结质量合格率92%,二界面胶结质量合格率85%,与同区块井相比,一界面合格率提高25%,二界面合格率提高40%,且在后期试采过程中无水窜的发生,可为解决固井过程中的水窜问题提供技术支撑。

In order to solve the problem of cementing water channeling,the cross-linked polymer microspheres BCP-3S with particle size of 100 nm was prepared using acrylamide,2-acrylamide-2-methyl propane sulfonic acid and acrylate as reaction monomer by referring to the principle of profile control and water plugging technology. The micro-morphology of polymer microspheres was observed by scanning electron microscopy and transmission electron microscopy. The conventional performance of polymer microsphere cement slurry,expansion test and self-sealing test of cement paste cracks were carried out. The results showed that the BCP-3S had good spherical shape,and there was no adverse effect on the conventional properties of cement slurry. The fluidity and strength of cement slurry decreased slightly after the addition of 0.6%(BWOC)BCP-3S,however,the rate of expansion of 7 d cement paste was up to 1.62%,which was far higher than that of the expansive agent currently used. When the cement paste cracks encountered water channeling,the polymer microsphere expander BCP-3S could further expand from about 100 nm to more than 600 nm,effectively filling and blocking the cracks to prevent water channeling. The technology was successfully implemented Guan XX adjustment well in Dagang oilfield. The qualified rate of the first interface cementing quality was 92%,and the qualified rate of the second interface quality was 85%,increasing by 25% and 40%,respectively,compared with that of the block wells,moreover,water channeling did not occur to during the later stage of trial production. It could provide technical support for solving water channeling problem in cementing process.