低渗透砂岩油藏水锁损害影响因素分析

Analysis of Factors Influencing Water Blocking Damage in Low-Permeability Sandstone Reservoirs

在低渗透油藏开发过程中,水锁效应广泛存在,严重影响油藏的开发。基于水锁机理,建立了定量预测水锁效应的数学模型,利用模型分析了流体侵入压差和毛细管力对水锁损害半径的影响及毛细管力和生产压差对水锁损害程度的影响。研究认为:随着流体侵入压差增加,水锁损害半径增大;随着毛细管力增加,水锁损害半径增加,水锁产生的表皮系数增大,水锁损害程度增加;随着生产压差的增加,水锁产生的表皮系数减小,水锁损害程度降低。

During the development of low-permeability sandstone reservoirs,there widely exists water block which severely affect oilfield development.Based on the mechanism of water blocking,mathematical models of quantitative forecast of water blocking effect are established;and the influence of liquid invasion pressure difference and capillary pressure on water block damage and the influence of capillary pressure and production pressure drawdown on water block damage severity are analyzed.The study shows that water blocking damage radius increases with the increase in liquid invasion pressure difference;water blocking damage radius increases,skin factor caused by water blocking increases and water blocking damage severity increases with the increase in capillary pressure;skin factor caused by water blocking decreases and water blocking damage severity decreases with the increase in production pressure drawdown.