WELL CLEANING METHOD Russian patent published in 2013 - IPC E21B37/00 E21B27/00 

FIELD: oil and gas industry.

SUBSTANCE: when the well is being cleaned, a layout consisting of a pipe string and a hydraulic sludger is lowered to the well. Hydraulic sludger is opened and filled with borehole fluid and swab is lowered to the pipe string. The fluid is extracted via the pipe string with the swab and the layout is removed from the well. Layout bottom is interconnected with the well head via an individual pipeline with possibility of the pipeline shut-off or connection to the atmosphere. After the hydraulic sludger is filled with the borehole fluid and the swab is arranged in the pipe string, the hydraulic sludger is closed. After that, individual pipeline is connected to atmosphere. Then, fluid is taken from the pipe string and the sludger with the swab at the closed hydraulic sludger. Volume of the removed fluid is filled with air via the individual pipeline. Then, the swab is removed from the pipe string and hydraulic sludger is opened. Hydraulic sludger and pipe string is filled with borehole fluid. If necessary, the operations are repeated.

EFFECT: improvement of the cleaning process.

1 cl, 1 dwg