Column filter is inserted into the column to protect a mud motor from foreign objects during the drilling process.

The filter consists of filter element and casing. Before going to mud motor the fluid is delivered into the column and goes through the filter that has a slot-type filter element with 5mm slots. All hard particles sized not more than 5mm are trapped by the filter element. Filter design allows to do the filter element cleaning at the drillsite, without any risk of getting foreign objects and cuttings inside the motor.