FILTER FOR WELLS Russian patent published in 2015 - IPC B01D39/12 

FIELD: oil and gas industry.

SUBSTANCE: filter for wells contains rigidly and tightly connected sections made out of joined along edges with axial tension cylindrical thin-wall filtering elements and two supports, on which with axial tension the first and last filtering elements of the section rest. The last support of the last section is tightly covered by the lid, and first support of the first section is tightly and rigidly connected with the submerged pump. The filtering elements are made as follows: filtering elements with one flat end by which they rest against the support, and with another cone end with cone angle α from 60 to 90°, and one element with external cone, and another element with internal cone; the intermediate filtering elements of the section are made with cone ends, with one external and another internal with cone angle α. The section filtering elements are connected with each other such that the external cone of the one element with axial tension enters in the internal cone of the other element making rigid tight joint. Inside the section of the filtering elements without radial clearance or with minimum permitted radial clearance the spiral compression spring with ground ends is inserted, the spring is wound such that first three or four turns of the spring at each of its two ends are wound close to each other with minimum permitted angle of lead. Along length of each filtering element of the section the spring is wound with such pitch that at its length uniformly two, three or four spring turns are located, and next two spring turns are wound close to each other with minimum permitted angle of lead, and are arranged in the assembled section at joint of the filtering elements such that one turn is located at end of one element, and another one - at end of the another element. Section of the filtering elements is aligned in the supports both along the centering shoulder of the support, and along two last spring turns in each group of the close wound turns located at spring ends, in each support three or four lock screw are screwed in till rest with tension against the spring turns and test of the screw head against sealing gasket, the lock screws are arranged along circle. The screw head height is selected such that clearance between the well wall or casing and end of the screw head will not exceed 0.2÷0.3 mm. Section supports are made with partition, in which through central hole and three or four bosses uniformly arranged along the circle are made. The first support of the first filer section is made with tail end with metric thread, on which till stop against the sealing gasket the intermediate spacer is installed with screwed in studs for securing to the submerged pump, and in the intermediate spacer of the first section the hollow cylindrical rod is rigidly installed, the cylinder has through holes uniformly distributed both along the rod generatrix, and in circumferential direction. The internal cavity via the central hole in the spacer is connected with suction cavity of the submerged pump. The internal cavities of sections are connected with each other via the holes in the central rod and boss, and support partitions. The internal cavity of the first section is connected with suction cavity of the submerged pump via the holes in the central rod and boss in the intermediate spacer that are located opposite to the support bosses. The rod with minimum permitted clearance passes through the central holes of partitions of the section supports. The central rod is made out of several parts connected by bushings screwed on both connected rod parts, and each connecting bushing is screwed on one of the connected rod parts till stop against partition of the last support of the last section of the sections package located along length of this rod part such, that the required axial tension is provided in joints of the filtering elements of the sections of this package. On the second connected rod part a round nut is screwed till stop against the connecting bushing, and on the end of the last part of the central rod the lid is screwed on till stop against the sealing gasket installed in the lid and last support of the last filter section such that between the filtering elements of sections of the last package of the filter the required axial tension is made, and lid is aligned as per central hole of the last support.

EFFECT: invention increases the filer capacity, rigidity and strength of the filtering elements in radial and axial directions.

3 cl, 5 dwg