黏弹性颗粒驱油剂的制备与性能

经过长期的注水开发,我国大部分油田已面临非均质性严重、剩余油分散等现状,依靠常规方法仍有近一半原油滞留地下无法采出。线型聚丙烯酰胺驱油剂在非均质油藏中沿高渗条带窜流,扩大波及体积能力差,无法起到大幅度提高采收率的作用。对此,创新设计了一种“交联-支化共存”新型分子结构,采用自由基聚合,建立了多官能引发体系,发明了动力学调控机制,研发了结构可控的黏弹性颗粒驱油剂(B-PPG)。B-PPG在性能上兼具部分水解聚丙烯酰胺和交联聚丙烯酰胺的双重优点:它既具有线型聚丙烯酰胺的增黏能力和在地层中的运移能力,同时又具有交联聚丙烯酰胺优异的耐温抗盐、耐老化能力和调节地层渗透率的能力。以B-PPG为主剂的非均相复合驱技术已应用于胜利油田聚驱后油藏,提高采收率8.5个百分点,最终采收率高达63.6%,实现聚驱后油藏高效开发。

Preparation and Properties of Branched Preformed Particle Gel

After long-term water flooding development,reservoir heterogeneity got serious and the residual oil became dispersed,therefore,nearly half the oil remained unrecoverable by traditional method.Linear partially hydrolyzed polyacrylamide(HPAM)flowed along high permeability zones in heterogeneous reservoirs,resulting in poor ability of enlarging sweep volume,thus it could not play a significant role in enhancing oil recovery.Then a novel structure with cross-linked network and linear branched chains was designed and structure controlled branched preformed particle gel(B-PPG)was developed by free radical polymerization in the presence of a multifunctional initiation system.B-PPG had good properties of increasing viscosity and migration liking HPAM,and good performance of temperature resistance and salt tolerance,aging resistance and improving core permeability as crosslinked polyacrylamide.The technology had been applied to the reservoirs after polymer flooding in Shengli oilfield,and the recovery factor had improved 8.5%with the ultimate recovery factor of 63.6%.It had become a new generation of chemical flooding technology after polymer flooding.