TREATMENT METHOD OF BOTTOM-HOLE ZONE Russian patent published in 2014 - IPC E21B43/25 

FIELD: mining.

SUBSTANCE: method involves pumping to a well perforation zone of a working agent, formation of depression differential pressure between the bottom-hole zone and a well cavity by creation of periodic pressure pulses in the bottom-hole zone in the form of a wave moving along the well cavity, which is formed at periodic opening of the well cavity on the mouth and its closing for periodic outflowing of well fluid and rise of pressure in the well cavity using valves. Outflow of fluid from the well cavity is performed through a well fluid drain valve attaching the well mouth and a drain reservoir. Well cavity pressure is increased through a fluid filling-up valve attaching the well mouth to a pressure fluid source. When the fluid drain valve is being opened, the fluid filling-up valve is closed at the same time. When the fluid drain valve is being closed, the fluid filling-up valve is opened at the same time. Opening and closing of valves is performed at intervals providing bringing of well fluid mass to the state of free vertical oscillations. Limits of pressure variation of pumped fluid are adjusted. Number of free vertical oscillations of a well fluid column and pumping rate of working agent is assumed depending on geological conditions. Well cavity fluid filling-up is performed by means of a pump from the drain reservoir. Drain and filling-up valves are combined into a common structure of a flow switch providing the possibility with opening of one valve to close another one and vice versa.

EFFECT: improving efficiency of the method owing to the possibility of bringing mass of well fluid column and working agent to back-and-forth movement state using small amount of additional equipment and simpler treatment.

2 dwg