低粘度堵剂在管外窜槽模型中的注入选择性研究

Selective injection of plugging agent of low viscosity in outside channeling model

为了研究堵剂在发生管外窜槽井的注入特性,根据管外窜槽模型,分析了低粘度堵剂的注入特性,指出不同渗透率地层的分流情况受窜流通道和地层渗透率的综合影响。在油水层渗透率一定的条件下,窜流通道渗透率越小,水窜层分流率越小;反之,窜流通道对水窜层分流率影响越小,并且最终分流率趋于定值。随着注入速度的增加,水层和油层的压力均增大。在窜流通道和油水层渗透率一定的条件下,若油水层压力不变,则油水层分流率不变。低粘度堵剂注入发生管外窜槽的油水层时,由于油水层压力确定了注入流体的分流率,同时由于油层压力小于水窜层压力,使大量堵剂进入油层,对地层造成严重伤害。因此,建议使用泡沫等具有分流效应的流体,减少对油层的污染。

In order to study the injection characteristics of the plugging agent in the event of pipe outside of the channeling wells, and according to the outside of the tube channeling model, the low viscosity plugging agent injected characteristics are studied herein, it is pointed out that the fluid branching within different permeability stratum condition is influenced comprehensively by the channeling circulation and permeability stratum. Under certain conditions of oil-water layer permeability, the smaller the permeability way of channeling circulation, the less water channeling layer diversion rate is; conversely, the less influence on channeling layer of water diversion rate; and eventually tending to be constant diversion rate. With the increase of injection rate, water level and reservoir pressure will increase. And, under certain circulation and oil-water layer permeability, if the oil-water level keeps constant pressure, the oil and water layer diversion rate will remain unchanged, and it indicates that oil-water level pressure determines the rate of oil and water diversion rate. When the low viscosity blocking agent is injected into the oil-water layer that occurred outside the pipe channeling, and the oil-water layer pressure will determine the diversion rate of the injected fluid. Due to reservoir pressure less than the pressure of water channeling layer, a lot of blocking agent will enter into the reservoir, and subsequently causing serious formation damage. So, we recommend the foam with fluid streaming effect that can reduce the pollution of reservoir.