【作者】 朱道义； 侯吉瑞； 王建斐； 韦琦； 吴璇；

【Author】 Daoyi Zhu;Jirui Hou;Jianfei Wang;Qi Wei;Xuan Wu;Research Institute of Enhanced Oil Recovery, China University of Petroleum;

【机构】 中国石油大学(北京)提高采收率研究院；

【摘要】 针对渤海油田的地层非均质性严重、水驱开发效果差等问题,研制了改性淀粉/AM/AA接枝共聚水基凝胶堵剂,考查了地层水矿化度、原油含量、粘土矿物以及pH值对该水基凝胶堵剂静态稳定性的影响,并采用填砂管模型和层内非均质模型对该水基凝胶堵剂的封堵效果和驱油效果进行了评价。通过实验优选出的改性淀粉/AA/AM接枝共聚水基凝胶堵剂的组成为2-4%改性淀粉、2-3%AM单体、0.5-2%AA单体、0.1-0.2%交联剂、0.0001-0.005%引发剂和0.05%稳定剂,该堵剂具有良好的耐盐性、耐油性及耐粘土性,体系pH值在1-7之间可调。该水基凝胶堵剂的稳定性好,放置在65℃下至少120天不发生破胶和脱水现象。在填砂管中注入0.1-0.3PV水基凝胶堵,成胶后后续水驱阶段存在明显的突破压力(367-4345kPa),封堵率在99.0%以上。采用层内非均质模型,水基凝胶堵剂封堵高渗层后,使岩心中的液流转向中、低渗层,提高波及体积,进而提高整体的采收率。更多还原

【Abstract】 In view of serious heterogeneity and poor water displacement recovery in Bohai Oilfield,in-situ starch-AM-AA gelling water plugging agent was developed.Effects of salinity,oil and clay mineral content,pH on static stability of this gel was studies.Finally,sandpack and intrastratal heterogeneity model were applied to study the plugging and recovery effect.The optimal gel was composed of 2-4%starch,2-3%AM,0.5-2%AA,0.1-0.2%crosslinker,0.0001-0.005%initiator and 0.05%stabilizer,which has excellent tolerance to salt,crude oil and clay mineral.it could gel at pH1-7 and kept stable at least 120 days at 65℃.After 0.1-0.3PV agent was gelled in sanpack,breakthrough pressure at the stage of subsequent water flooding was obvious,367-4345 kPa,and plugging coefficient was higher than99.0%.The strong gel could plug the highest permeable layer in intrastratal heterogeneity model,diverting the subsequent oil-displacing agent into other two layers,improving sweeping volume and oil recovery.更多还原