水侵对油井出砂的影响

提出了地层出砂过程包括剪切破坏产生屈服区和砂粒运移两个阶段的概念，分析了水侵对油井出砂的影响，水侵加速地层出砂的原因如下：产水能溶解砂粒之间的一部分胶结物，使地层的胶结强度下降；粘土膨胀，渗透率降低，破坏油流的连续性；产生水锁效应，增加油流阻力。同时，建立了粘着力模型，利用该模型分析了水侵量对油井出砂的影响。

The Effect of Water Cut on Sand Production

It is pointed out in this paper thatthe sand production includes two steps. The first step is the developmentof the plastic area induced by the shear failure of the formation. And the second step is that the sand grains are carried by the fluid flow. The effect of the water cut on the sand production is also analyzed. Sand production is increased by the water cut owing to the following reasons:1. The bonding material among the sand grains is dissolved by the water,which cause the formation strength decrease. 2 . The permeability is decreased by clay dilation. 3.The waterdestroys the oil continuity. 4. The waterlock is formed, which increases the fluid flow resistance. Meanwhile,the model to predict the cohesion force is developed. Using this model,the effect of the water cut quantity on the sand production is analyzed.