TECHNOLOGY OF SHORT RADIUM CASING SIDE-TRACKING HORIZONTAL DRILLING IN J-33 SP 71 WELL

This project was one of the key projects included in the 9-th National Five-year Scientific Research Program. In order to exploit low permeability, low potential, high condensation point bearing formations, a side-track operation on 177.8 mm casing in interval of 2060.20~2067.93 m in J-33-71 well was conducted. After the cement plug was drilled out, a short radium horizontal well with start point of 2061.00 m was drilled using domestic tools and instruments. The well had its true final depth of 2354.82 m, vertical depth of 2121.36 m, displacement of 262.32 m, length of horizontal section of 211.05 m, radium of curvature of 35~49 m and inclination at the target point of 89.4°. All the indexes have met the designed requirements. A 7.78 t/d average output of crude oil was obtained at the production test. The main operational cautions and problems in rig-site engineering practices were also described.