Ren Long, Zhao Cong, Sun Jian, Jing Cheng, Bai Haitao, Li Qingqing, Ma Xin
School of Petroleum Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Shaanxi Key Laboratory of Advanced Stimulation Technology for Oi & Gas Reservoirs, Xi'an 710065, China.
Gels. 2025 Jul 10;11(7):536. doi: 10.3390/gels11070536.
This study addresses the unclear mechanisms by which preferential flow channels (PFCs), formed during long-term waterflooding, affect nano-gel microsphere (NGM) flooding efficiency, utilizing CMG reservoir numerical simulation software. A dynamic evolution model of PFCs was established by coupling CROCKTAB (stress-porosity hysteresis) and CROCKTABW (water saturation-driven permeability evolution), and the deep flooding mechanism of NGMs (based on their gel properties such as swelling, elastic deformation, and adsorption, and characterized by a "plugging-migration-replugging" process) was integrated. The results demonstrate that neglecting PFCs overestimates recovery by 8.7%, while NGMs reduce permeability by 33% (from 12 to 8 mD) in high-conductivity zones via "bridge-plug-filter cake" structures, diverting flow to low-permeability layers (+33% permeability, from 4.5 to 6 mD). Field application in a Chang 6 tight reservoir (permeability variation coefficient 0.82) confirms a >10-year effective period with 0.84% incremental recovery (from 7.31% to 8.15%) and favorable economics (ROI ≈ 10:1), providing a theoretical and engineering framework for gel-based conformance control in analogous reservoirs.
本研究利用CMG油藏数值模拟软件，探讨了长期注水过程中形成的优势渗流通道（PFCs）影响纳米凝胶微球（NGM）驱油效率的不明机制。通过耦合CROCKTAB（应力 - 孔隙度滞后）和CROCKTABW（水饱和度驱动的渗透率演化）建立了PFCs的动态演化模型，并整合了NGMs的深部驱油机制（基于其膨胀、弹性变形和吸附等凝胶特性，以“封堵 - 运移 - 再封堵”过程为特征）。结果表明，忽略PFCs会使采收率高估8.7%，而NGMs通过“桥堵 - 滤饼”结构使高导流带渗透率降低33%（从12降至8 mD），将水流转向低渗透层（渗透率增加33%，从4.5升至6 mD）。在长6致密油藏（渗透率变异系数0.82）的现场应用证实有效期超过10年，采收率提高0.84%（从7.31%提高到8.15%）且经济效益良好（投资回报率≈10:1），为类似油藏基于凝胶的调驱提供了理论和工程框架。
