WELL FLUID FILTRATION METHOD Russian patent published in 2016 - IPC E21B43/08 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used for cleaning borehole fluid. Method consists in lowering and lifting a borehole fluid cleaning filter from well; the filter containing a filtering screen and slotted nozzle. Filter is lowered at the rate that does not allow dirt sticking on the screen and slots at lowering. After lowering a calming period is allowed during which stirred impurities sediment in the range of placement of the filter. Lifting is performed at a rate of excluding the possibility of impurities being pressed through the screen and slot due to fluid head. During lifting periodic stops are made to allow impurities sediment from the screen and slots.

EFFECT: higher efficiency of filtration.

1 cl, 1 dwg