Abstract: In order to get knowledge about the watered out situation of productive formations, water flooding efficiency and residual oil saturation of Gudao reservoir of Shengli Oil Field which fell in its late development period, X5-J142 well was completed with glass fiber polymer casing in the interval of 1209.40~1290.90 m out off the total casing length 1330 m. The characteristics, completion operation requirements and engineering technology were introduced in the paper.