METHOD FOR DYNAMIC WELL OPERATION WITH ELECTRIC PUMP HAVING VARIABLE-FREQUENCY DRIVE Russian patent published in 2008 - IPC F04B47/00 E21B43/00 

FIELD: oil production from wells, particularly to operate wells provided with electric pumps, for instance with submersed pumps with ac electronic motors.

SUBSTANCE: method involves pumping-out liquid with electric pumps having ac electronic motor; periodically increasing ac electronic motor rotational frequency as motor operates in steady-by regime at time intervals defined by duration of transient processes in well-reservoir system, wherein rotational frequency is increased for value determined by threshold of motor current sensitivity, to reduce ac electronic motor current value below threshold one at a given rotational frequency corresponding to pump starvation; making a decision whether critical dynamic liquid level is achieved in well from pump starvation. Threshold value of ac electronic motor current is determined from test-bench characteristics with taking into decision of density of liquid to be actually pumped-out. After pump starvation detection the ac electronic motor is shifted into standby mode with decreased rotational frequency to prevent ac electronic motor overheating. Standby mode duration is enough to change dynamic liquid level in well. After standby mode termination ac electronic motor rotational frequency is again increased to value less than pump starvation one, wherein difference between said two values is equal to predetermined one. After that electric pump is brought into operation in mode near that providing critical dynamic liquid level in well to increase liquid influx in well.

EFFECT: increased efficiency of selection of working pump regime, which maximizes well rating due to elimination of pipe string pressure measurement.

3 dwg