PROCEDURE FOR OPERATION OF WELL WITH ELECTRIC PUMP EQUIPPED WITH VARIABLE FREQUENCY DRIVE Russian patent published in 2011 - IPC E21B43/00 

FIELD: oil and gas production.

SUBSTANCE: procedure consists in start-up of pump for specified process rate of feeding voltage frequency during bringing pump to specified frequency of stationary mode with accelerations in case of liquid supply failure and in supply of liquid with pump under stationary mode at specified frequency. Also, there are periodically performed cycles alternating pump down of liquid with pump and accumulation of liquid in well to compensate unsteady supply and for maintenance of balance between withdrawal of liquid from well and liquid influx. Pump down is carried out due to modulation of frequency in interval of values corresponding to parameters maintaining pump output; when there is reached a specified value of pressure in a string, liquid is accumulated in a well. For this purpose frequency of feeding voltage in a current cycle is lowered to stop of pump output with successive keep of maximal frequency whereat the pump does not resume supply. In a phase of liquid influx into a well in a current cycle there is performed modulation of voltage frequency of electric pump feed in interval of frequency values corresponding to parameters of the pump variable during stop and start of supply. When during liquid influx there is obtained pressure value established at pump suction, there is resumed supply of liquid with the pump, reversing it to pump down at frequency as high, as frequency of resumed supply. Further, the cycle is repeated. The pump is shifted to a stationary mode, when frequency of supply recovery in a current cycle reaches value not over a specified frequency. In case of failure of liquid supply with the pump at its bringing to a specified frequency of the stationary mode during specified time in interval of values of parameters of recovery and stop of pump output, there is performed additional modulation of recovery frequency of liquid supply. It is done before recovery of pump output. Also, output is performed at frequency with specified deviation from obtained before additional modulation with frequency of output disruption. Further, the pump is continued to be brought to specified frequency of the stationary mode with established rate of bringing well to an operating mode.

EFFECT: raised efficiency of operation and bringing well to operating mode with electric pump with variable frequency drive at continuous pump operation and at following specified process rate of bringing well to operation mode including at failures of output during pump bringing to specified frequency of stationary mode; reduced mechanical impurities lifting and prevention of problems at well operation.

2 dwg