致密油藏压裂液滤液返排率影响因素室内实验

发布时间：2018-04-22 21:33

本文选题：压裂液滤液返排 + 毛细管渗流　；参考：《油气地质与采收率》2017年01期

【摘要】：致密油藏和页岩油藏储层致密、孔隙喉道细小,在压裂液滤液返排过程中,大量压裂液滤液滞留于地层,导致返排率极低。在微观渗流的基础上,利用毛细管束模型,建立压裂液滤液返排数学模型,分析不等径毛细管中油驱压裂液滤液返排过程的主要影响因素。利用胜利油区樊154区块天然岩心进行室内驱替实验,分析岩心渗透率、模拟油粘度、返排压差和模拟油—压裂液滤液界面张力4个因素对压裂液滤液返排率的影响。结果表明:岩心渗透率对压裂液滤液返排率的影响较大,当渗透率由1.276×10~(-3)μm~2降低到0.13×10~(-3)μm~2时,压裂液滤液返排率可减小20%左右;当模拟油粘度由6.459 mPa·s降低到1.192 mPa·s,模拟油—压裂液滤液界面张力由14.617 mN/m降低到0.021 mN/m时,压裂液滤液返排率均可提高15%左右;返排压差越大,压裂液滤液返排率越高,当返排压差超过8MPa时,继续增加返排压差对压裂液滤液返排率增幅的影响不大。
[Abstract]:The tight reservoir and shale reservoir have fine pore throat, and a large number of fracturing fluid filtrates remain in the formation during the process of fracturing fluid filtrate reflux, resulting in a very low recovery rate. On the basis of microscopic percolation, the mathematical model of filtrate backflow of fracturing fluid was established by using capillary bundle model, and the main influencing factors of filtrate backflow of oil flooding fracturing fluid in unequal diameter capillary were analyzed. Using natural core of Fan 154 block in Shengli oil area to carry out laboratory displacement experiments, the effects of core permeability, simulated oil viscosity, backflow pressure difference and interfacial tension of simulated oil-fracturing fluid filtrate on fracturing fluid filtrate recovery rate were analyzed. The results show that the core permeability has a great effect on the filtration rate of fracturing fluid. When the permeability is reduced from 1.276 脳 10 ~ (-3) 渭 m ~ 2 to 0.13 脳 10 ~ (-3) 渭 m ~ 2, the filtrate return rate of fracturing fluid can be reduced by about 20%. When the simulated oil viscosity was reduced from 6.459 mPa s to 1.192 mPa s, and the interfacial tension of the simulated oil-fracturing fluid filtrate decreased from 14.617 mN/m to 0.021 mN/m, the back drainage rate of fracturing fluid filtrate increased by about 15%, and the greater the pressure difference, the higher the filtrate return rate. When the back discharge pressure difference exceeds 8MPa, the increase of back discharge pressure difference has little effect on the increase of back discharge rate of fracturing fluid filtrate.
【作者单位】：中国石化江苏油田分公司石油工程技术研究院;中国石油大学(华东)石油工程学院;中国石化胜利油田分公司石油工程技术研究院;壳牌(中国)项目技术有限公司;
【基金】：国家自然科学基金项目“基于离散裂缝模型的低渗透油藏压裂水平井流动模拟研究”(11102237)
【分类号】：TE357.12

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