CLEANING METHOD FOR BOTTOMHOLE FORMATION ZONE OF INJECTION WELL Russian patent published in 2007 - IPC E21B37/00 E21B43/20 

FIELD: oil production industry, particularly to clean bottomhole oil formation zone, which provides additional cleaning of flow string inside injection wells during low-permeable reservoir exploitation or exploitation of reservoirs with operational characteristics decreased because of well zone contamination.

SUBSTANCE: method involves separating well groups having low and high intake capacities in hydrodynamic system; operating conduit gates; transferring liquid from injection wells having low intake capacities into ones having high intake capacities. Volume of liquid to be transferred from injection wells having low intake capacities into ones having high intake capacities does not exceed sum of volume of flow string lowered in injection well having low intake capacity and volume of well section defined by flow string shoe and perforated reservoir roof. Then liquid is poured into tank at head of injection well having low intake capacity for further liquid recycling.

EFFECT: decreased intake capacity of low-permeable reservoirs, prevention of high-pressure distribution conduits contamination with solid particles, decreased time between injection well bottom zone cleaning operations and decreased costs for reservoir pressure maintenance.

1 ex, 1 dwg