A New Generation of Submersible Electrical Motor Protectors with a Dynamic Labyrinth for Operation in Aggressive Environment with High Concentration of Free Gas and Solids

In this work, the authors study the problems associated with the operation of oil wells using electric centrifugal pumps. The authors acknowledge the negative factors that lead to an increase in solids concentration in the upper part of the submersible electric motor protectors, higher possibility of end seal failures and shortening of service life of serial products. The replacement of a gravitational labyrinth by a dynamic one in the upper part of the motor seal protector is one of the ways to improve the reliability of the protector in the operational environment with high concentration of gas and solids. The proposed seal protector design makes it possible to considerably increase the estimated efficiency of solids separation (by 300 times), improve reliability, as stable running is ensured even after the failure of end seals, and reduce the mounting length by 25–40 %, resulting in cost saving and improved maintainability as fewer parts are used. This conceptually new operation principle facilitates the creation of a new generation of highly reliable seal protectors, capable of working effectively in challenging well conditions. Thus, the new design should supersede all serial motor seal protectors in conventional wells and add a market segment in complicated wells.

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