高压水射流处理地层的机理及试验

介绍了高压水射流深穿透处理地层解堵的三种物理机理,即低频旋转水力波、高频振荡射流冲击波和空化噪声超声波。实验室测试了解堵工具的旋转速度特性、冲击压力特性和射流冲击压力随喷距的变化规律。结果表明,随着泵压的增加,解堵工具的旋转速度增大,射流对套管壁面及炮眼冲击力也随之增大。在泵压一定的条件下,随着喷距的增加,射流冲击压力逐渐减弱。在试验的泵压20.0MPa条件下,射流压力作用深度可达600mm以上。经辽河油田23口油井现场试验表明,高压水射流深穿透解堵技术平均单井增油幅度达20%～50%,有效率90%以上,有效期90d以上,是高含水期油田强化生产、增产增注、提高采收率的一种高效新技术。

A STUDY ON MECHANISMS AND EFFECTS OF PLUG REMOVAL NEAR WELLBORE WITH HIGH PRESSURE WATER JET

The mechanisms of the laboratory and field test results of plug removal near wellbore with high pressure water jet are introduced.A new tool for plug removal by three kinds of compound physical effects of low frequency hydraulic pulse, high frequency oscillating jet impact and cavitation noise are developed.The effects of jet pressure on rotating speed, jet impact pressure and the effects of jet distance on impact pressure are experimentally tested.The experiments have demonstrated that the rotating speed of the tool head and the jet impact pressure on casing surface increase while pump pressure are higher.Jet impact pressure is detectable for large radius of near wellbore formation up to 600 mm at tested pump pressure of 20.0MPa.Field tests at 23 oil wells in Liaohe Oilfield have shown that the plug removal near wellbore with high pressure water jet can increase oil production by 20% to 50%, valid ratio over 90% and the valid period are over 90 days.