低渗油藏活性纳米颗粒减阻增注解析模拟方法

1)中国石油大学(华东)石油工程学院,山东青岛266580; 2)中国石油大学(华东)非常规油气开发教育部重点实验室,山东青岛266580; 3)山东省油田化学重点实验室,山东青岛266580

油田开发; 低渗油藏; 降压增注; 活性纳米颗粒; 特征线法; 疏水滑移

A novel analytical simulation method of utilization of surfactant-active nanoparticles for well injection enhancement in low-permeability reservoirs
LIU Xupeng1, YUAN Bin1, 2, 3, DAI Caili1, 2, 3, LI Yue1, and HAN Mingliang1

1)School of Petroleum Engineering, China University of Petroleum(East China), Qingdao 266580, Shandong Province, P.R.China;2)Key Laboratory of Unconventional Oil & Gas Development, Ministry of Education, China University of Petroleum(East China), Qingdao 266580, Shandong Province, P.R.China;3)Shandong Key Laboratory of Oilfield Chemistry, Qingdao 266580, Shandong Province, P.R.China

oilfield development; low permeability reservoirs; pressure drop and injection enhancement; surfactant-active nanoparticles; method of characteristics(MOC); hydrophobic slip

DOI: 10.3724/SP.J.1249.2021.06563

备注

为研究活性纳米颗粒在低渗储层中减阻增注的作用机理,真实模拟储层孔隙表面粗糙条件,构建了周期性矩形凹槽结构的微管模型和粗糙表面纳米颗粒受力均衡模型,形成了孔隙表面活性纳米颗粒极限附着体积分数模型.利用特征线法解析模拟了低渗储层孔隙活性纳米颗粒悬浮-附着-堵塞耦合的渗流过程.综合考虑注入纳米颗粒附着及堵塞等储层损害机制和颗粒附着产生的滑移效应,建立活性纳米颗粒降压增注理论模型.结果表明:注入纳米颗粒后,岩心两端压降(垂直表面的压强差)较未注入时下降明显,降压率可达40%; 通过比对注入前后注水指数的大小,注入活性纳米流体后岩心注水能力得到显著提高.该模型为低渗油藏活性纳米流体降压增注技术提供了一定的理论基础.
In order to study the mechanism of surfactant-active nanoparticles in drag reduction and injection enhancement in low-permeability reservoirs and to simulate the rough condition of the pore surface of the reservoirs, we construct a microtube model with periodic rectangular groove structure and a force balance model of nanoparticles on rough surface to get the limit adhesion concentration fraction model of surfactant-active nanoparticles on pore surface. The method of characteristics(MOC)is used to analyze and simulate the seepage process of the suspension-adhesion-plugging coupling of surfactant-active nanoparticles in pores of low permeability reservoirs. By comprehensively considering reservoir damage caused by the mechanisms such as particle attachment and blockage and the slip effect established by nanoparticle attachment, a theoretical model for resistance reduction and injection enhancement of surfactant-active nanoparticles has been formed. The results show that comparing with the core without nanoparticles flooding, the pressure drop of the core decreases significantly after the injection of nanoparticles, and the pressure drop reaches 40%. At the same time, by comparing the water injection index before and after injection, the core injection capacity is significantly improved after the surfactant-active nanofluid injection. This model provides a certain theoretical basis for the technology of pressure reduction and injection enhancement of surfactant-active nanoparticles in low permeability reservoirs.
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