March 28, Shenbei Metro Shenyang Metro Oil Machinery Plant came good news from the plant independently developed "rodless reciprocating reciprocating submersible electric pump" access to national invention patents, which will completely replace the world a hundred years of oil production applications The "kowtow machine." Shenyang Metro Petroleum Machinery Factory using the principle of magnetic levitation technology, after more than three years of hard research, developed its own "rodless CNC reciprocating submersible pump." This oil recovery equipment environmental protection and energy saving more than 50%, to overcome the traditional "kowtow machine" energy consumption, supplies, covers an area of ​​large, low efficiency and limited oil production shortcomings, and in December 2007 the State Intellectual Property Office utility model patent. Through the operation of multiple wells in Daqing and Liaohe Oilfields, it has been proved that all the technical indexes of the product exceed the performance of the original oil recovery equipment and can completely replace the traditional oil recovery machinery.