不同类型注入液体对返排影响实验研究

Experimental Study of the Influence of Different Types of Injected Liquids on Flowback

不同类型压裂注入液体表现出不同的返排特性。选择合适的注入液体有助于提高压裂返排,从而提高压裂效果。对国内某低渗透区块岩心进行室内物理模拟实验研究,主要进行了岩心润湿反转实验及渗透性、润湿性对注入液体返排影响的实验研究。实验结果显示,该区块低渗透岩心容易发生水锁伤害,加入优选的润湿反转剂后能够提高接触角,从而降低水锁伤害。不同的渗透率、润湿性对液体返排有一定影响,随着渗透增加,返排量相对较大。水湿指数越高,返排率越低。实验结果对压裂液返排施工具有很好的指导意义。

Different types of fracturing injected liquids show different flowback characteristics. Choosing appropriate injected liquid is helpful to improve fracturing flowback and then improve the fracturing effect. This paper takes indoor physical simulation experimental study of one domestic low-permeability block core, and it mainly includes the study of the influence of core wettability reversal experiment and permeability, wettability on injected fluid flowback. The experimental results show that the low-permeability core in this block is easy to have the water locking damage, after adding the optimized moist reverse agent, it can improve the contact angle, thereby reduce the water locking damage degree. Different permeability and wettability have different effects on the fluid flowback, besides, with the increase of permeability, the flowback quantity will be relatively large. The higher the water-dampness index, the lower the flowback rate will be. The experiment result has very good guiding significance for fracturing fluid flowback construction.