This paper briefly describes the working principle of the self-excited oscillating nozzle and the experimental results of the pressure impulse characteristics and its frequency distribution under different ambient pressures. The transmitting law of the pressure fluctuation is introduced along the casing in both the axial and the radial directions. In addition, it presents the principle of water-injection with self-excited oscillation, the designation of the injection tool, and the field experimentation results. The field results indicate that the self-excited oscillating cavitation jets can be used as an effective way to prolong the production period of the well because the jets minimize formation block up. The average injection pressure was reduced by 2.1MPa, and the averaged volume of daily water injection for a single layer increased by 29m3. It can also prolong the water injecting time of the general waterinjecting well

High pressure water jet removing impurities in formations is a new way developed recently to increase oil production and injected-water. First of all, this paper presents the main reasons of formation plugging, the basic principles of high pressure rotating water jets removing impurities and the laws of the tool's rotating speeds, impact pressure and relations between impact pressure and nozzle stand-off. The field-test results obtained from over 500 oil and water-injection wells in Liaohe, Shengli, Zhongyuan, Huabei etc., indicate that this technology has such advantages as simplicity of use, cost effective, high success rate, wide adaptability, and significant effectiveness. From this, it is profitable and promising to increase production in highly water-cut oilfields.

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2010MPa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。

论述了水射流技术在我国石油工程中的研究和应用情况，应用实验方法建立了淹没非自由射流压力及水功率衰计算模型，建立了以井底获得最大大功率，优选水力参数设计的新方法和新模型，应用瞬态流理论及水产学原理建立了两种谐振腔的基本关系式和结构数学模型，建立了在钻井双向应力作用下，岩石裂纹发展方向模型，介绍了研制的3种新型高效钻头，即加长喷嘴牙肿晖罚哉裆淞髯晖泛蜕淞骷盎盗o掀蒲易晖罚o雇o怂淞骷际跫际踉诔o哐股淞髯昃oo碛图暗蜕o筒乜o桑岣卟墒章实确矫娴挠t们熬啊？