DRILL STRING FILTER AND METHOD FOR MANUFACTURE THEREOF Russian patent published in 2021 - IPC E21B43/08 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to the oil and gas industry and can be used for extraction of liquids and gases from the interior of the earth and is intended for cleaning the drilling agent from mechanical impurities and scale. The apparatus is comprised of a body in form of a perforated tubular cylindrical or conical lateral surface, a bottom and an open top with a flange, the dimensions whereof correspond with the dimensions of the drill string. The casing has differently distanced holes of varying sizes with a decreasing downward void rate. The casing thickness therein reaches 5 mm. The casing for all elements is manufactured using laser cutting. Perforation is made therein on a stainless steel casing using a laser cutting machine and software on VNITEP machines.

EFFECT: service life of the filter is increased and the costs of its manufacture and operation are reduced due to uniform wear of the filter along the entire length thereof with uniform distribution of the drilling agent flow due to gradual change in the size of the holes and the distance between said holes along the length of the filter without increasing the void rate of the holes downward.

2 cl, 3 dwg