两相渗流阻力法在转注井吸水能力研究中的应用

Application of two-phase flow resistance method in studying water absorbing capacity of conversion well

由于未考虑平面上相态的变化和两相渗流阻力,吸水指数常规计算方法得出的值均为一个定值,与实际生产不符。为了研究注水井吸水指数随注水量的变化规律,在考虑平面上相态变化的基础上,应用两相渗流阻力法,建立了米吸水指数和米累计注水量关系模型。实例应用表明,运用该模型计算的理论米吸水指数与实测值相差不大,且变化趋势一致。在注水初期,井底附近含水饱和度迅速增加,水相相对渗透率迅速上升,因此注水井米吸水指数迅速上升;当米累计注水量达到一定数值后,注入水波及区含水饱和度上升速度减小,水相相对渗透率缓慢上升,导致米吸水指数上升缓慢。该方法为注水井的合理配注提供了理论依据。

Because the conventional methods do not consider the phase change in the plane and the two-phase flow resistance, injeetivity index is a constant value, which is contradictory with actual production. In order to study the relation between injeetivity index and water injection rate and through considering phase change in the plane, a relational model is established based on two-phase flow resistance. Example application of the theoretical model shows that the calculated value is approximate to measured value and the trend of change is consistent. In the early period of water injection, the water saturation near the bottom hole increases rapidly, the relatiw~ permeability of water rises quickly and meter injectivity index rises rapidly; When the meter cumulative water injection reaches a certain value, the rising velocity of water saturation in the injected water swept area decreases, the relative permeability of water rises slowly and meters injeetivity index rises slowly. The method can provide a theoretical basis tot injection proration in water injection well.