WELL RECOVERY METHOD Russian patent published in 2014 - IPC E21B43/24 E21B43/25 

FIELD: oil and gas industry.

SUBSTANCE: well recovery method involves depreservation and treatment of a shaft, cleaning of the cavity and wells from deposits of viscous hydrocarbons, cleaning of a filter in a production formation area, creation of excess pressure in the near-formation zone of the well, and superimposition of thermal and acoustic actions. After the well depreservation is completed, an adjustable pressure release valve is installed on the head, an independent drilling machine is lowered on a conducting rope to the well till it is stopped in deposits of viscous hydrocarbons. The above deposits are developed, evaporated and extracted from the shaft by actuating a thermal gas generator of the independent drilling machine due to action of a working steam-gas agent. After that, the well cavity is filled with working liquid - liquefied carbon dioxide gas up to 1/5 from filters; the above valve is shut off after having adjusted it for automatic actuation at maximum allowable pressure for the cavity of the above well; to the thermal gas generator of the independent drilling machine there supplied is an electric signal via the conducting rope for its actuation. The steam-gas agent leaving the above machine creates excess pressure in the well cavity, and at the same time, the working liquid temperature is increased. Acoustic action on the near-well zone of the formation is performed due to periodic actuation for pulse opening of the valve of the well head. All the above actions are combined as to time of the process. Characteristics of pressure, temperature and acoustic characteristics are chosen based on a calculation of maximum permissibility of the shaft on values of those loads; the above process is performed till "formation-filter zone of the well" permeability is set.

EFFECT: improving efficiency of action on a productive formation in the near-well zone, and integration of all the actions into a single process at the distance of up to 50 m from the well; reduction of time and labour costs.

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