Abstract: Although the traditional profile control methods can displace and plug high reservoir and effectively use medium permeability reservoir. It is impossible to make effective use of low permeability reservoirs. The high formation pressure affects the injection volume and development effect of profile control and flooding agent. Taking medium⁃low permeability reservoirs as the research object, experimental study on weak gel and water alternating injection was carried out to reveal the mechanism and effect of cyclic deep profile control. The experimental results showed that the effect of cyclic deep profile control method was better than that of traditional profile control method. Compared with core No.1 (whole injection), the recovery of core No.2 (two rounds) was increased by 3.6%, and that of core No.3 (three rounds) by 5.3%. With the increase of injection cycles, the recovery rate increases, and the cyclic deep profile control method could improve the recovery rate of low permeability reservoir on the basis of effectively utilizing medium and high permeability layers. The field test results showed that after 2 rounds of gel deep flooding test, the cumulative oil volume in the experimental area was 1.53×104 t, and the recovery stage was 1.66%. The results have important practical significance for improving oil recovery in medium⁃low permeability reservoirs.

Key words: Low?medium permeability reservoir, Cyclic injection, Weak gel, Deep profile control

摘要： 传统调驱方式能够驱替并封堵高渗透层，有效动用中渗透层，而无法实现对低渗透层的有效动用，且高地层压力影响调驱剂注入量和开发效果。针对这些问题，以中低渗透油层为研究对象，开展弱凝胶与水交替注入实验研究，揭示周期性深部调驱机理及效果。实验结果表明，周期性深部调驱效果明显好于传统调驱方式效果，与1号岩心（整体注入）相比，2号岩心（2个轮次）采收率增幅为3.6%，3号岩心（3个轮次）采收率增幅为5.3%；随着注入轮次的增加，采收率增加；周期性深部调驱方式可在有效动用中高渗透层的基础上，提高低渗透层的采收率。矿场实验结果表明，经过2个轮次凝胶深部调驱试验，试验区累积增油量为1.53×104 t，采收率提高1.66%，周期性弱凝胶深部调驱效果显著。研究成果对提高中低渗透油藏原油采收率具有重要的现实意义。

关键词: 中低渗透油藏, 周期, 弱凝胶, 深部调驱