特种油气藏 ›› 2025, Vol. 32 ›› Issue (6): 116-123.DOI: 10.3969/j.issn.1006-6535.2025.06.014

• 油藏工程 • 上一篇    下一篇

稠油油藏注CO2+降黏剂过程中流体赋存特征及协同增效机理研究

章杨1, 王晓燕1, 王海峰1, 张祖峰1, 张楠1, 鲍磊1, 庞占喜2   

  1. 1.中国石油大港油田分公司,天津 300280;
    2.中国石油大学北京,北京 102249
  • 收稿日期:2024-07-24 修回日期:2025-09-02 出版日期:2025-12-25 发布日期:2025-12-31
  • 通讯作者: 庞占喜(1977—),男,教授,2002年毕业于石油大学(华东)石油工程专业,2008年毕业于中国石油大学(北京)油气田开发工程专业,获博士学位,现从事稠油油藏开发和数值模拟研究工作。
  • 作者简介:章杨(1987—),男,高级工程师,2010年毕业于中国石油大学(华东)石油工程专业,2016年毕业于该校油气井工程专业,获博士学位,现从事注气提高采收率方面的研究工作。
  • 基金资助:
    国家自然科学基金面上项目“多孔介质中纳米颗粒与发泡剂协同构建Pickering泡沫机制及其运移规律”(52074321)

Characteristics of fluid distribution and synergistic enhancement mechanisms during CO2+viscosity-reducing agent injection in heavy oil reservoirs

ZHANG Yang1, WANG Xiaoyan1, WANG Haifeng1, ZHANG Zufeng1, ZHANG Nan1, BAO Lei1, PANG Zhanxi2   

  1. 1. PetroChina Dagang Oilfield Company,Tianjin 300280,China;
    2. China University of PetroleumBeijing,Beijing 102249,China
  • Received:2024-07-24 Revised:2025-09-02 Online:2025-12-25 Published:2025-12-31

摘要: 针对中深层稠油油藏热采开发难度大、采收率低的问题,根据CO2在稠油中的溶解特性和降黏剂的作用原理,基于微观渗流模拟技术,开展协同降黏机理实验和协同增效机理实验,研究CO2及CO2+降黏剂协同作用提高稠油采收率机理。实验表明:在油藏条件下,CO2可溶于稠油,形成直径为0.016~0.051 mm的微小泡沫油,显著改善原油流动性,驱替后波及系数达到56.4%,采出程度达到37.3%;降黏剂可使原油形成微细的乳状液滴,扩大CO2波及范围,降黏率超过99.0%,波及系数达到65.3%,采出程度达到46.2%。研究表明:CO2通过溶解膨胀和显著降黏作用改善原油流动能力,其与降黏剂的协同作用能大幅度提升驱油效率和波及范围;泡沫油的形成和乳状液滴的封堵是提高波及效率的关键机制。该研究对中深层稠油油藏提高原油采收率及实现CO2地质封存具有重要的实践指导意义。

关键词: 稠油油藏, CO2, PVT实验, 可视化实验, 波及效率, 协同增效

Abstract: Faced with the difficulties of thermal development and low recovery in mid-deep heavy oil reservoirs,and based on the CO2 solubility in heavy oil and the operational principle of viscosity-reducing agents,micro-scale flow simulations were conducted involving synergistic viscosity reduction and enhanced production experiments.The study examined the mechanism by which CO2 and CO2+viscosity-reducing agent jointly improved heavy oil recovery.Experimental results showed that under reservoir conditions,CO2 dissolved in heavy oil to form minute CO2-in-oil bubbles(0.016-0.051 mm in diameter),significantly improving crude oil mobility;after displacement,the swept coefficient reached 56.4% and oil recovery degree 37.3%.The viscosity-reducing agent caused crude oil to form fine emulsion droplets,expanding the CO2 sweep area;the viscosity reduction rate exceeded 99.0%,and the swept coefficient reached 65.3%,with recovery up to 46.2%.This indicated that CO2 improved oil flowability via solution-induced expansion and viscosity reduction,and its synergistic action with the viscosity-reducing agent could substantially enhance displacement efficiency and sweep extent.The formation of foam oil and blockages by emulsified droplets were the key mechanisms improving sweep efficiency.This study provides practical guidance for enhancing recovery in mid-deep heavy oil reservoirs and for realizing CO2 geological styorage.

Key words: heavy oil reservoir, CO2, PVT experiment, visualization experiment, sweep efficiency, synergistic enhancement

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