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01.12.2014
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Testing Tandem Pumping Plants
As part of the improvement of sucker-rod screw pumps program, tandem pumping plants, drive strings of ring-cross section sucker-rod screw pumps (hollow sucker rods) and rod blades were tested at the development sites of "Sheshmaoil" OAO. Theoretical calculation showed that during the angular strain of the details, the biggest stresses occur in the surface layers of a torsion shaft, in the central part they are much smaller, and on the longitudinal axis they are zero. Consequently, in a solid shaft the material in the central part is underloaded, and its contribution to the shaft strength is very small. Calculations showed that the rational cross section for a torsion shaft as a torsion bar is ring-cross section. This cross section is characteristic of tubing pipes and hollow sucker rods. According to the formulas, in comparison with hollow cross-section rods like ШН-22 and hollow ones, piped sucker rods sized 32х4.5 are 2.25 times stronger, and the rigidity of piped sucker rods exceeds the ШН-22 by 3.28 times. In order to confirm the theoretical calculations, hollow shafts manufactured by the Ocher Machine-building Plant were installed in wells No. 2 and 3 of "Sheshmaoil" OAO. The rods have been used for a year, and not a single twist-off has been registered. The use of ШНТ-32 rods as torsion shafts gave a positive result, since they are designed with externally upset ends, that is, they are of equal strength.Back to the list