水平井环空化学封隔材料——MMH/MT/AM体系的流变性能研究

Rheological Properties of an Annular Chemical Plugging Materials ——MMH/MT/AM System for Horizontal Wells

针对筛管完井水平井管外多段出水不易封堵的难题,使用4%铝镁混合层状金属氢氧化物(MMH)/钠质黏土(MT)(质量比1∶1)和4%丙烯酰胺(AM)研发了一种水平井环空化学封隔材料MMH/MT/AM体系。研究了体系在不同组分浓度、剪切速率及剪切恢复时间、温度和促凝剂浓度条件下的流变特性。研究结果表明:当MMH/MT由1%增至4%,温度由30℃升至70℃时,体系的结构恢复速率和恢复强度均会显著提高;剪切速率由1000 s-1增至7000 s-1时可以加剧体系结构的破坏程度,但体系恢复后的弹性模量相差不大。此外,促凝剂可使得体系形成具有空间网络结构的粒子包覆层,当其浓度升高时,体系的固化时间大幅缩短,固化后的强度也大幅增加,加入60 mg/L促凝剂时体系固化后的弹性模量即高于38 k Pa,管外环空石英砂充填时体系封堵强度达到8.3 MPa/m。电镜扫描实验表明,体系在受到剪切破坏后,其内部粒子呈分散状分布;随着恢复时间的延长,粒子间逐渐呈层状规律缔合聚集,静置60 s后已基本构建成明显的层状网络结构。

It is difficult to shut off the useless water production from horizontal wells because of the big number of water points. To solve this problem, a kind of annular chemical packing martial （MMH/MT/AM system） was developed using 4% aluminum-magnesium layered hydroxide/sodium soil （MMH/MT） and 4% acrylamide （AM）. Effects of the influencing factors on rheological properties of-the MMH/MT/AM system were explored. Results showed that when the MMH/MT concentration increased from 1% to 4% and the temperature rose from 30℃ to 70℃, both the recovery rate and the recovery strength of the system were obviously enhanced. With the increase of the shear rate from 1000 s^-1 to 7000 s^-1, the damage degree of the system structure was sharply intensified, but the elasticity modulus after system recovered was similar to that of system before shearing.Moreover, a particle-coating with a three-dimensional network structure was formed after the addition of the accelerating agent. With the increase of the accelerating agent concentration, the consolidation time of the system was rapidly shortened and the strength of the consolidated system was obviously improved. The elasticity modulus after the system recovered exceeded 38 kPa when the concentration of the accelerating agent Was only 60 mg/L. The plugging strength of the system in the annular space was 8.3 MPa/m when the annular space was packed with sand. Results of the scanning electron microscope tests indicateed that the particles inside the system were dispersed after the shearing action; with the extension of the recovery time, dispersed particles gradually aggregated and associated in layers and a obvious layered network structure was constructed after the recovery time exceeded 60 seconds.