氮气泡沫调驱微观机理和封堵性能影响因素研究

Study on Microscopic Mechanism and Factors Affecting the Sealing Characteristics for Nitrogen Foaming Flooding

为了认识氮气泡沫调驱技术的微观机理和封堵性能影响因素,指导矿场调驱实施工作,采用微观仿真模型、填砂管模型及人造岩心,对氮气泡沫调驱体系进行了室内实验研究。结果表明,氮气泡沫调驱的微观机理主要为气泡顶替机理、液膜破灭携油机理和负压泄流机理。影响封堵性能的主要因素是气液比、渗透率和注入速度。气液比为1∶1时封堵效果最好,封堵能力随着渗透率的增加而增大,并在达到某一渗透率时达到极值;封堵能力随着注入速度的增加而增大,并在达到某一临界速度时增幅趋于平缓。

In order to understand nitrogen foaming flooding technology for microscopic mechanism andfactors affecting the sealing characteristics and guide the field work , microscopic simulation model, sandpack and artificial core were adopted to study for foam system by lab experiment. The results showed thatmicroscopic mechanism of nitrogen foaming flooding is bubble to replace, bursting with oil film andnegative pressure drainage mechanism. The main factors affecting the sealing performance is the gasliquidratio, permeability and injection rate.Gas-liquid ratio for plugging effect is the best when 1：1,sealing ability increased with the increase in permeability, and reach the maximum values at a certainpermeability , sealing ability increased with increasing injection rate, and reached a critical velocityincreases gently.