Research on wear-resistance of mud lifting pump impeller for marine riser-less drilling

Abstract:

The centrifugal-pump-type riser-less mud lifting pump is adopted in offshore drilling， lifting mud by motor-driven impeller rotation. During long term operation， abundant cuttings carried in drilling fluid cause severe impeller wear， which seriously impairs normal service of the mud lifting pump. Therefore， it is necessary to adopt wear-resistant treatment for impellers to improve their wear and corrosion resistance. In this study， impeller substrate materials were optimized， surface wear-resistant treatment processes were investigated， and wear-resistance tests were carried out. The test results show that 2205 duplex stainless steel possesses favorable comprehensive properties and is suitable for riser-less mud lifting service conditions. Tungsten carbide supersonic spraying achieves the most significant improvement in impeller wear-resistance. Duplex stainless steel is recommended as the impeller substrate material for mud lifting pumps， combined with tungsten carbide supersonic surface spraying， so as to extend the service life of mud lifting pumps.