根据材料冲蚀磨损理论和磨料射流切割原理，对利用水力喷砂射孔技术切割套管和近井地层岩石的机理及其影响因素进行了分析。在实验室条件下进行了水力喷砂射孔地面模拟实验，并在胜利油田现场进行了施工工艺设计和试验。实验结果表明，在压力为23～24MPa的条件下，水力喷砂射孔能有效地穿透套管并在天然砂岩上射出直径30mm以上、深达780mm的孔眼，现场试验证实水力喷砂射孔油井增产效果明显。水力喷砂射孔增产的机理主要是解除近井地带污染，松弛密实圈，避免炮弹射孔的压实污染，增加地层渗透率并扩展油流通道。

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。

采用离散涡方法模拟了两种不同形状哨嘴的喷嘴出口流场旋涡结构和压力分布。模拟结果表明，射流在喷嘴出口和哨嘴出口形成的旋涡结构在流场及其他涡元的作用下，向下游运动，在流场中某个地方形成低压区，这有助于诱发空化现象。对两种不同喷嘴的出口流场进行比较发现，哨嘴形状对形成的射流流场的旋涡结构有很大影响。因此，研究和应用空化射流必须考虑喷嘴出口哨嘴形状的影响。

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.

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