Abstract: A field test was carried out in a vertical Well J17-1 in Shengli Oilfield to validate the feasibility of hydra-jet sidetracking of micro-radial laterals,which could provide guidance for further research. The pressure loss in flexible hose was tested at different flow rates,and the ejecting force of self-propelled multi-port nozzle was tested. The results showed that the pressure loss in flexible hose was high,and the flow rate,ratio of the flow rate of the forward to that of backward port of the jet nozzle,and the wellbore diameter had significant effects on ejecting force,which provided guidance for hydraulic parameters design and pump pressure prediction during operation. Four laterals,one 20 m long and the other three 50 m long,were drilled in two different layers—861.5 m and 864.8 m based on well selection and the designed operation procedures,meeting the desired goals. The field test proved the reliability of the hydra-jet sidetracking of horizontal micro-radial hole,which provided a new way for stimulation of depleted oil wells and low-permeability reservoirs.