Detection of well fluid contamination in sealed fluids of well pump assemblies

摘要

A submersible well pump assembly include a rotary pump driven by an electrical motor. A seal section operably connects between the motor and the pump for reducing a pressure differential between motor oil in the motor and well fluid surrounding the pump assembly. The pump assembly contains a sealed fluid. A sensor mounted to the well pump assembly detects contamination of the sealed fluid by well fluid encroaching into contact with the sealed fluid. The sensor may be mounted in the motor or the seal section to detect well fluid contamination of motor oil. The sensor may be mounted in a secondary pump that has that has temporary barriers to block the entry of well fluid into a buffer fluid contained in the secondary pump while the secondary pump is in a storage condition within a well.

主权项

1. An apparatus for pumping well fluid from a well, comprising:
at least one submersible well pump assembly for lowering into the well to pump well fluid, the at least one submersible well pump assembly comprising: a rotary pump; an electrical motor operably connected to the pump; a sealed fluid contained in the well pump assembly; a seal section operably connected between the motor and the pump for reducing a pressure differential the sealed fluid contained in the motor and the well fluid in the well; at least one sensor mounted to the well pump assembly that detects contamination of the sealed fluid by the well fluid encroaching into contact with the sealed fluid; a well fluid contamination first sensor mounted to the submersible well pump assembly and a well fluid contamination second sensor mounted to the submersible well pump assembly at an axial distance from the first sensor, relative to a longitudinal axis of the submersible well pump assembly, each of the first and second sensors being of a type that will detect a presence of well fluid encroachment into the sealed fluid; and means for receiving signals from the first and second sensors indicating a presence of well fluid encroachment into the sealed fluid and for determining a time delay between a well fluid presence signal received by the first sensor and a well fluid presence signal received by the second sensor to estimate how fast well fluid is leaking into the sealed fluid.