METHOD FOR FILTER DE-MUDDING Russian patent published in 2006 - IPC E21B37/08 

FIELD: oil production, particularly for well output increase and well repair, namely cleaning in situ of down-hole filters, screens, or gravel packs.

SUBSTANCE: method involves forcing liquid or gas flow through filter in direction opposite to that of formation fluid filtration through the filter; extracting formation fluid from formation and supplying the formation fluid with liquid or gas flow from filtered space to well head via hole annuity; determining well technical conditions; lowering flexible pipe of coiled tubing facility in well up to filter bottom; removing sand-clay plug from filter by flushing thereof with the use of the flexible pipe, wherein liquid or gas flows are forced through the filter by supplying thereof via the flexible pipe along with water-jet effect creation. Filter is de-mudded by feeding surfactant substance mixture into the flexible pipe. Methanol may be supplied in doses to prevent hydrate growth. Before flexible pipe removal the well is purged.

EFFECT: increased efficiency.

1 dwg