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

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.