石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (5): 1682-1699.doi: 10.11743/ogg20250518

• 方法技术 • 上一篇    

裂缝-基质型刻蚀芯片的渗吸-驱替机理微流控实验

杨柳(), 董广涛, 姜晓宇(), 李明峻, 公飞, 朱凯, 裴奕杰   

  1. 中国矿业大学(北京) 隧道工程灾变防控与智能建养全国重点实验室,北京 100083
  • 收稿日期:2025-02-20 修回日期:2025-04-14 出版日期:2025-10-30 发布日期:2025-10-29
  • 通讯作者: 姜晓宇 E-mail:shidayangliu@cumtb.edu.cn;18801191349@163.com
  • 第一作者简介:杨柳(1987—),男,博士、副教授、博士研究生导师,深部岩体温度-应力-渗流-化学耦合、CO2地质封存与驱煤层气-页岩油气、非常规油气提高采收率。E‑mail: shidayangliu@cumtb.edu.cn
  • 基金项目:
    国家自然科学基金面上项目(52374014)

Microfluidic experimental study on imbibition-displacement mechanism of tight oil reservoirs using fracture-matrix etched chips

Liu YANG(), Guangtao DONG, Xiaoyu JIANG(), Mingjun LI, Fei GONG, Kai ZHU, Yijie PEI   

  1. [State Key Laboratory for Tunnel Engineering,China University of Mining and Technology (Beijing),Beijing 100083,China]
  • Received:2025-02-20 Revised:2025-04-14 Online:2025-10-30 Published:2025-10-29
  • Contact: Xiaoyu JIANG E-mail:shidayangliu@cumtb.edu.cn;18801191349@163.com

摘要:

水力压裂是致密砂岩油藏开发的主要方式,研究微观渗流机理及剩余油流动动态对于指导处于高含水阶段的致密油藏开发具有重要意义。为研究压裂液注入过程中的流体运移规律及渗吸-驱替耦合作用机理,基于裂缝-基质型双重介质光刻芯片模型,开展了微流控模型可视化驱油实验。分析研究了在渗吸-驱替耦合作用下的油-水界面运移、油滴剥离以及微观残余油分布微观特征。结果表明:①在压裂液注入双重介质模型后,流动过程兼顾裂隙指进、孔隙-裂隙交互渗吸以及孔隙驱替。注入速度较慢时渗吸作用的主导性较强,对近裂缝区的死孔油波及范围较广。随着注入速度增加,交互渗吸作用减弱,波及范围及采收率逐渐降低,采收率主要由孔隙内的驱替作用贡献。②当添加表面活性剂后,压裂液对油滴和壁面残余油簇的剥离作用增强,同时添加表面活性剂后液体对残余油的击打促排效果显著,壁面残余油被大量剥离。当流体突破后,在稳定驱替阶段也会持续剥离壁面残余油,极大地增强了驱油效果。③渗吸和驱替过程中,因为壁面的不同粗糙度以及不同孔隙体间流速和压力的影响导致存在残余油。根据形状及其分布,残余油分为球状残余油、单壁面膜状残余油、孔喉柱状残余油、双壁面膜状残余油、壁面折柱状残余油和壁间连片状残余油6类,其中柱状和膜状残余油分布的范围较广。

关键词: 渗吸-驱替耦合, 裂缝-基质双重介质模型, 表面活性剂, 微流控实验, 水力压裂, 提高采收率, 致密砂岩储层, 油藏开发

Abstract:

Hydraulic fracturing serves as a primary technique for developing tight sandstone oil reservoirs. Investigating the microscopic seepage mechanism and flow dynamics of residual oil helps guide the exploitation of tight oil reservoirs with high water cut. To explore fluid migration patterns and the imbibition-displacement coupling mechanism during fracturing fluid injection, we conduct visual flooding experiments using microfluidic models based on fracture-matrix laser-etched chips (also referred to as the dual-medium microfluidic models). We analyze the movement of the oil-water interfaces, the stripping of oil droplets, and the microscopic distribution of residual oil under the influence of imbibition-displacement coupling. The results indicate that, following the injection of fracturing fluids into a dual-medium microfluid model, the flow process involved fracture fingering, pore-fissure interactive imbibition, and pore displacement. A lower injection rate corresponded to a stronger dominance of imbibition, resulting in a broader sweep range of oil in dead-end pores near the fractured zone. With an increase in the injection rate, the interactive imbibition weakened, leading to a gradual reduction in sweep range and oil recovery, which was primarily attributable to pore oil displacement. The addition of surfactants enhanced the ability of fracturing fluids to strip oil droplets and residual oil clusters adhering to pore walls. Moreover, fracturing fluids containing surfactants significantly impacted residual oil and promoted its drainage. Consequently, a substantial amount of residual oil was stripped from the pore walls. Following fluid breakthrough, residual oil on pore walls continued to be stripped during the stable displacement stage, significantly enhancing the overall flooding effect. Residual oil remained in the imbibition and flooding processes due to variations in wall roughness and the impact of flow rates and pressure across different pores. Based on its morphology and distribution, residual oil can be categorized into six types: spherical, single-wall-adhered membranous, pore-throat columnar, double-wall-adhered membranous, wall-adhered bent columnar, and inter-wall contiguous types. The columnar and membranous types, among others, are extensively distributed.

Key words: imbibition-displacement coupling, fracture-matrix dual-medium model, surfactant, microfluidic experiment, hydraulic fracturing, enhanced oil recovery (EOR), tight sandstone reservoir, reservoir development

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