Patent ID: 7611338
Filing Date: 2009-11-03
Classification: F04D,H02K

Abstract:
1. A method of connecting tandem upper and lower subs of an electrical submersible pump assembly, the upper sub having a base that interconnects with a head of the lower sub, each of the subs having a drive shaft with a splined end that mates with the splined end of the other drive shaft, the base of the upper sub having a central cavity surrounding the splined end of the drive shaft of the upper sub, the method comprising: (a) providing a vent port in the base of the upper sub extending from the central cavity to an exterior of the base of the upper sub; (b) introducing a quantity of oil into each of the subs while the subs are apart from each other to substantially fill each of the subs; then (c) opening the vent port, and with a lower end of the central cavity open, lowering the upper sub downward into engagement with the lower sub, which causes oil in the upper sub to flow downward and into the central cavity, the open vent port allowing any air trapped in the central cavity to displace out through the vent port.