摘要
非均质性是油气储层的基本特征,酸化施工采用暂堵剂封堵高渗、促使酸液作用于低渗层,是提高非均质储层酸化改造效果的关键措施。为了解决现有高分子暂堵剂成胶时间不可控、残渣伤害严重等问题,采用生物材料海藻酸钠(SA)和黄原胶(XG)通过半互穿方式形成具有高强度可降解的新型暂堵剂SAXG。以变形量和成胶时间为目标优化了体系的最优质量百分比0.7%SA+0.3%XG,采用流变仪测试了凝胶的流变性以及延迟成胶效果,以残渣含量描述体系的可降解性,通过扫描电子显微镜(SEM)明确了SAXG半互穿网络与SA凝胶的区别,最后采用岩心流动实验验证了体系的转向酸化效果。研究结果表明,SAXG成胶时间范围为14~456 min;SAXG在盐水和酸液中可完全降解;暂堵酸化后岩心渗透率比常规酸化后提高了2.85倍;降解后岩心渗透率恢复率达98.6%。SAXG可有效促使酸液转向,从而提高酸化改造效果。
Heterogeneity is a fundamental characteristic of oil and gas reservoirs.The key measure improving the acidizing effect of heterogeneous reservoirs is diversion methods,which diverting agents are used to plug the high permeability layer and promote acid acting on the low permeability layer.In order to solve the problems of uncontrollable gelation time and serious damage of synthetic polymer diverting agents.A novel diverting agent SAXG with high strength and biodegradability was formed through semi-interpenetration using biomaterials sodium alginate(SA)and xanthan gum(XG).The optimal mass percentage of the system was optimized to 0.7%SA+0.3%XG with the goal of deformation and gelation time.The rheological properties and delayed gelation characteristics of this diverting agent were tested by rheometer;The degradability of the system was described with the content of residue;The difference between SAXG semi-interpenetrating network and SA gel was confirmed through scanning electron microscope(SEM);Finally,the core flow experiment was used to verify the divert acidizing effect of SAXG.The results showed that the gelation time range of SAXG is 14 to 456 min;The SAXG can be completely degraded in saline and acid solutions;The permeability of the core after diversion acidizing increased by 2.85 times compared to conventional acidification;The recovery rate of core permeability after degradation reached 98.6%.The SAXG can effectively promote the diversion of acid solution,thereby improving the effectiveness of acid stimulation.
作者
卢星辰
刘健
杜娟
高小荣
许勇
任小庆
LU Xing-Chen;LIU Jian;DU Juan;GAO Xiao-Rong;XU Yong;REN Xiao-Qing(Sinopec Star Co.,Ltd.,Beijing 100083,China;Sinopec Green Energy Geothermal Development Co.,Ltd.,Xiong'an 071800,China;Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China)
出处
《应用化学》
CAS
CSCD
北大核心
2024年第9期1271-1283,共13页
Chinese Journal of Applied Chemistry
基金
新星石油公司科技项目(No.FW2099-0047)资助。
关键词
可降解
半互穿网络
暂堵剂
转向
酸化
Degradable
Semi-interpenetrating network
Temporary plugging system
Diversion
Acidizing
