Dynamic compression compensator for submersible pumps

Abstract

A dynamic variable compression ring for use in submersible pumps. where the variable compression ring compensates for metal compression ring measurement errors during assembly. The dynamic variable compression ring also allows for thermal heating of the internal pump components, thus maintaining the desired diffuser compression values.

Description

FIELD OF THE INVENTION[0001]This invention relates to a variable compression methodology to aid in the prevention of diffuser spinning, overheating. and destruction of downhole submersible pumps.BACKGROUND[0002]In current designs, reference FIG. 1 submersible pumps are an assembly of diffusers 5 and impellers 3 contained within the pump housing 4, with a shall 2 powered by an external motor (not shown) to supply the rotational power for the impellers 3 which are keyed to the shaft 2. The impellers 3 provide the lift for the well fluids in order to move the fluids to the surface. The forces associated with the impeller 3 rotation and fluid lift will, at times, cause associated diffusers 5 to rotate inside the housing 4 when they should not. The diffuser 5 rotation generates considerable heat, and can cause housing 4 and / or adjacent stage failures.[0003]To prevent the diffusers 5 from spinning due to the hydraulic reaction of the impellers 3, the diffuser stack, the common reference t...

AI Technical Summary

Benefits of technology

[0010]In a preferred embodiment, the present invention is the design and implementation of a variable compression device to relieve precise measurement errors during the assembly of downhole submersible pumps. The invention provides a flexible compression component, expanding to provide the necessary compression if the metallic compression tube is cut short, and compressing to provide the necessary compression if the metallic compression tube is cut too long. The invention allows for variable compression caused by normal operational heating of the impellers / diffusers stack within the submersible pump.

Problems solved by technology

The diffuser 5 rotation generates considerable heat, and can cause housing 4 and / or adjacent stage failures.

Typical problems that arise with this arrangement include the following:compression ring 1 variability, ring cut too short—allows diffusers 5 to move and can lead to diffuser 5 spin, housing 4 overheating, and eventual destruction of the pump.compression ring 1 variability, ring cut too long—places stress on diffuser 5 side walls which can lead to side wall collapse and eventual pump failure through reduced output or overheating.compression ring 1 variability, ring cut too long—normal operation, but when internal pump parts are heated by normal operation, thermal expansion may create unusual pressures on the diffusers 5, again leading to side wall collapse and eventual pump failure through reduced output or overheating.

The variability in the length of the compression ring 1 can be attributed due to human error during measurements, human error during length calculations. human error during cutting of the ring itself, relaxation of the diffuser / impeller stack after the hydraulic pressure is removed, as well as other related assembly items that could affect the total assembly.

Compound the possible human errors with normal expansion characteristics of the material being used and pump failure can occur.

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