APPLICATIONAL RESEARCH ON SCREW PUMP DRIVED BY HOLLOW ROD

In the downhole screw pump production system that is driven by electric motor on the surface, trouble often results from the break-off of the sucker rod. This paper compares the property of the hollow rod with that of the solid rod, and conducts case calculation. Calculation results indicate that the hollow rod possesses more superiority. In the screw pump well, comparing with the CYG25 solid sucker rod, when using KG36 hollow rod, the safety factor can be increased by nearly 1 times. While adopting the hollow rod, if the strength of the sucker rod tool is improved, the strength of the entire sucker rod string will be improved simultaneously. This paper introduces the status and effect of the hollow rod applied in the screw pump well in offshore Chengdao oilfield of Shengli Field.