毛管力与含水饱和度对岩石出砂的影响

The Effect of Capillary Pressure and Water Saturation on Sand Production

出砂是影响油井生产能力的一个重要因素。防砂工艺技术的关键在于正确分析油层出砂的原因 ,并判断油层出砂机制。通过室内岩心流动试验 ,研究了毛管力、含水饱和度对岩石出砂规律的影响。结果表明 :在束缚水饱和度时 ,毛管力对岩石表面微粒起到稳定作用 ;当油水同时流动时 ,岩石出砂临界流速随着含水饱和度的升高而下降 ,出砂量随着含水饱和度的增大而增大。疏松砂岩油藏开采过程中应合理设计生产工艺参数 ,控制含水体积分数上升 。

Sand production is an important factor, which affects oil well productivity. Analyzing the reason and apprehending the mechanism of sand production are the critical technique for sand prevention. The effect of capillary pressure and water saturation on sand production has been researched through the core flow test in this paper. The result of experiments demonstrates capillary pressure may stabilize the particle on the sandstone at the minimum wetting phase saturation. When water and oil are flowing at the same time, the critical velocity of sand production decreases with the increasing of water saturation. During the process of developing the loose sand reservoir, the parameter of technology should be designed rationally in order to dominate water content ratio and prevent sand production in bulk.