凝胶与化学剂段塞式多轮次交替注入调驱技术应用研究

The majority of water or polymer flooding reservoirs have already entered the period of high water cut in our country，so how to further tap the part of residual oil is the urgent problem to be solved for all the oilfield during the later stage of high water cut, which is also the focus of the study on the further EOR methods..This topic combine the weak gel profile control technology with the methods of chemicals flooding which use the polymers, surfactants and polymer/surfactant compound system, by utilizing flooding methods of slug alternative injection, on the base of detailed analysis of the oil displacement mechanism, by means of testing the gelling characters and stability of the gel system, the interfacial tension measurement of the surfactant and the compatibility between gel system and surfactant, the gel system and chemicals which used for the further profile control and oil displacement are selected. The experiment of injection characteristics for the gel and surfactant was carried out with the rectangular artificial core, to optimize the slug size and injection rounds which will be fit for the gel and chemicals slug alternative injection. By utilizing the artificial large flat-panel model, the oil drive experiment is carried out to study the injection characteristics and the oil displacement efficiencies of the gel and chemicals slug alternative injection. Meanwhile, Optimize the slug size and injection rounds with the combination of numerical simulation methods, the best method of gel and chemicals slug alternative injection is confirmed. It provides a favorable basis that this technology will be a further technique for tapping the residual oil and EOR.

我国大多数水驱或聚驱油藏都已经进入高含水后期，如何进一步挖潜这部分剩余油是目前各高含水后期油田亟待解决的问题，也是进一步提高采收率方法研究的重点。.本课题将弱凝胶调剖技术与聚合物、表面活性剂或聚表二元复合体系等化学剂驱油方法紧密结合，采用段塞式交替注入的方式进行驱油，在详细的调驱机理分析基础上，通过室内凝胶体系成胶特性、稳定性、表面活性剂界面张力测量及凝胶与表面活性剂等化学剂配伍性实验，筛选出进一步调驱用的凝胶体系和化学剂。通过长方人造岩心凝胶与表面活性剂注入特性实验，优选凝胶与化学剂交替注入调驱的段塞大小和注入轮次。通过人造大平板模型研究凝胶与化学剂交替注入驱油的注入特性和驱油效果。同时结合数值模拟方法，优化交替注入段塞大小以及交替注入轮次，确定出最佳的凝胶与化学剂交替注入方式，为该项技术成为高含水后期油藏进一步挖潜剩余油、提高采收率技术提供有利的依据。

聚驱后油藏仍有50％左右的原油不能开采出来，如何有效驱出聚驱后油藏剩余油，进一步提高原油采收率成为亟待解决的问题。本次研究提出了将凝胶调驱技术和化学剂驱油技术结合起来以多轮次交替注入的方式提高聚驱后油藏的原油采收率。针对凝胶、化学剂配方筛选、凝胶与化学剂交替注入调驱机理、调驱效果影响因素及调驱方式等重点问题，本次研究通过室内静态、动态评价方法，筛选了凝胶与化学剂配方，确定了凝胶与化学剂交替注入段塞的大小；通过人造长方岩心、微观驱油模型和宏观可视化驱油模型模拟了驱油过程，揭示了凝胶与化学剂段塞式多轮次交替注入微观渗流机理、宏观调驱机理和协同作用机理，明确了凝胶与化学剂段塞式多轮次交替注入调驱效果的主要影响因素及影响规律；利用数值模拟技术，优化了不同条件下的调驱参数及调驱方案。该项目的研究成果将为聚驱后进一步提高采收率技术的研究与应用提供理论与技术支持。在研期间，共发表论文13篇，其中EI检索7篇，共申请发明专利7项，其中授权1项，参加国内学术交流会议12人次，国际学术交流会议5人次，共培养博士生1名、硕士生11名。