Abstract:The screen in open hole,a commonly used new horizontal well completion method,is easy to be polluted and sealed by drilling mud. Foamed acid washing is often used in the cleaning process with a cup-type packer and nitrogen-enriched mixed gas emission,which has the disadvantage of washing unthoroughly and easily falling off the rubber on the cuptype packer. The jet can be produced at high energy pulse through the throttling pipe string for the foam acid washing technology by high pressure water jet. It can effectively remove mud cake and mud pollution in the whole screen section and the flow condition near wellbore can be thoroughly improved. This technology has been applied in16 wells of Gudao oilfield. By the end of June 2015,two to three times of mud and formation pollutants were drained compared to those by traditional acid washing and mixed gas emission. For the steam injection thermal recovery wells,the steam injection pressure decreased more than 1 MPa. The incremental oil of single well was more than 2 tons. The technology has significant production effect.At the same time,the technology can achieve sand control effect by filling outside tube when the conventional well-flushing is used. It can effectively protect the screen in the open hole and the formation outside the tube.