氮气泡沫抑制双水平井SAGD井间窜流可视化研究

Visualization Research on Nitrogen Foam Restraining the Interwell Flow during Dual Horizontal Well SAGD

双水平井SAGD是开发稠油油藏一种有效前沿的技术手段。双水平井SAGD开发稠油油藏时,注采井间局部易发生窜流.导致油井生产汽窜。含水率上升。对此利用二维物理可视化机理模型.以辽河油田曙一区杜84块馆陶油层地面脱气原油为实验原油,研究当水平井注汽开发过程中井间窜流后,注入的氮气泡沫运移、聚集、封堵机理。实验结果表明,由于油水黏度差异及储层非均质性,注采井间易发生窜流,注入蒸汽沿注采井间向前推进,产生明显的主流通道,不利于双水平井SAGD注采井间建立稳定连通关系和剩余油有效动用:注入的氮气泡沫首先进入主流通道并占据大孔道,在喉道的剪切作用下形成大量气泡,泡沫沿窜流通道运移并聚集,起到封堵作用,有利于抑制井间蒸汽或热水的窜通,使得后续注入流体改变流动方向,实现双水平井井间剩余油均匀动用。

Dual horizontal well SAGD is an effective advanced technique for developing the heavy oil reservoir.When dual horizontal well SAGD is applied to developing the heavy oil reservoirs,the channeling is easy to occur between injection and production wells,resulting in steam channeling and water cut rising in oil wells.Surface degassed crude in Guantao reservoirs of Du84 block,Shul area,Liaohe Oilfield was researched for the experiment.A two-dimensional physical visualization mechanism model was applied to the study of the mechanism of nitrogen foam migration,accumulation and plugging after interwell channeling during the steam stimulation in the horizontal well.The experimental results showed that the channeling was easy to occur between injection and production wells due to the difference of oil and water viscosity and heterogeneity of reservoir.The injected steam advanced between the injection and production wells,and obvious main channel was formed,which is not favorable for the establishment of stable connectivity between injection and production wells during the dual horizontal well SAGD and the effective producing of remaining oil.The injected nitrogen foam first enters the main channel and occupies the high-capacity channel,and a large number of bubbles formed ,migrated,gathered and plugged up.The effect makes the subsequent fluid turn,which helps to restrain the channeling of steam or hot water between wells.And then the remaining oil in the double horizontal wells was evenly produced.