Method of Operating a Well Using a Pump Assembly with a Variable-Frequency Drive

摘要

The method and device of exploitation of well by pumping unit with variable-frequency drive involes periodic repetition of the cycles including pumpdown, search for frequency when delivery stops and accumulation and at the same time to ensure such extraction of fluid from well which is equal to its inflow it is necessary to choose unit with higher capacity in comparison with inflow of fluid from formation into well and during the cycles the pumpdown-accumulation ratio is corrected depending on the results of the previous cycles until the pumpdown-accumulation time ratio stops to change and the torque at which the delivery stops is determined based on the equality of the current torque of the downhole motor shaft and check torque which is pre-determined based on stepwise drop of torque of the downhole motor shaft in the point when delivery stops when supply voltage is decreased.

主权项

1. A method of exploitation of a well using a pumping unit with a variable-frequency drive, comprising periodically repeating pumpdown, search of stopping delivery frequency, and accumulation cycles, the method comprising:
selecting a pumping unit with higher production capacity in comparison with inflow of fluid from formation into the well for ensuring extracting an amount of the fluid equal to the inflow; during the cycles correcting the pumpdown-accumulation ratio depending on the results of previous cycles until the pumpdown-accumulation time ratio stops changing; and determining when the delivery stops based on a current torque on a shaft of a downhole motor being equal to a check torque, wherein the check torque is predetermined based on a stepwise drop of a torque on the shaft of the downhole motor shaft at a point when the delivery stops at a decrease of a supply voltage.