METHOD FOR INCREASING WELL PRODUCTION Russian patent published in 2008 - IPC E21B43/00 

FIELD: oil and gas.

SUBSTANCE: present invention relates to extraction of liquid from wells using mechanical equipment, with submerged centrifugal pumping units with an adjustable electric drive. The method involves pumping liquid out of the well with an electrically driven submerged vane pumping unit, which alternates with accumulation of liquid in the well with the pumping unit shut off; the pumping unit capacity is adjusted using the cumulative time-integrated capacity, by changing the ratio of the duration of the period of pumping liquid from the well and that of liquid accumulation in the well. According to this invention, liquid is pumped with a pumping unit with a capacity of over 80 m³/day, which is more than two times greater than the calculated well production rate in the steady operation mode. The pressure developed by the unit during liquid pumping from the well is adjusted by changing the pump speed so that the pump efficiency in the whole adjustment range is not less than 0.9 of the maximum efficiency for the corresponding rotation speed. As the well production rate decreases, process operations for production rate increase are carried out on the well. For that purpose, the duration of the period of liquid accumulation in the well is selected so that the volume of the accumulated liquid exceeds the volume of liquid that the internal tubing string cavity can contain. The duration of the period of liquid pumping from the well is selected so that the pumped liquid volume does not exceed the accumulated liquid volume and exceeds the volume of liquid that the internal tubing string cavity can contain. The maximum possible pump rotation speed is selected, at which the pump impellers do not float up. The frequency and duration of well production rate increase operations are determined experimentally so that the additional oil volume recovered as a result of the well production rate increase operations would exceed the oil volume lost during the well production rate increase operations. For wells operated in the continuous mode, a different method of well production rate increase is provided.

EFFECT: increased oil recovery volume due to well production rate increase and its maintenance at constant level during long-term well operation.

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