特低渗透油藏注水作用规律探讨

Study on Effects of Water Injection in Ultra-low Permeability Oil Reservoirs

在油田开采注水过程中,探讨特低渗透油藏岩石的岩性、物性变化规律,制定合适的注水开发方案。以十屋油田透营城组特低渗储层岩石为研究对象,开展储层条件下的液相—岩石固相的实验研究,对反应前后的矿物相、膨胀应力、孔喉结构进行分析。结果表明:作用前后,矿物相的变化微弱,粘土矿物的存在,储层岩石存在吸水、膨胀、压缩和重整过程,致使孔喉结构变小,储层物性变差。

As a good understanding of ultra - low permeability oil reservoirs＇ lithological character and physical properties variation rule is very necessary for making a proper plan about water injection, the paper takes a liquid phase - - soild phase experiment on ultra- low permeability oil reservoirs in Touying Formation, Shiwu oilfield. Moreover, mineral facies , pore texture and swelling stress before and after the experiment are recorded and analyzed. The result shows that variation of mineral facies is little, which indicates the existence of clay mineral. Moreover, the process of water absorption, expansion, compres- sion and reformation happen in reservoir rocks makes the pore texture shrink and reservoir physical property become poor.