RU2490431C1 - Well strainer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device contains a perforated body and thin polymer discs with discrete particles connected to one of their bases thus forming labyrinthine channels in between. Discrete particles are made as polymer pin of identical height; they are oriented perpendicular to the base plane.

EFFECT: increase in filtering efficiency, decrease in labour intensity during manufacturing.

2 dwg

Description

The invention relates to downhole filters used in oil production to prevent the removal of solids with recoverable reservoir fluid.

Known downhole filter, which contains a perforated housing and a filter element consisting of filter layers and a granular filler and coated externally with a fleecy material (A.S. No. 5887242 of the USSR, ЕВВ 43/08, 1978).

The disadvantage of the filter is the high hydraulic resistance and increased loss of pressure of the pumped liquid, as well as the complexity and complexity of its manufacture.

Known downhole filter, consisting of a perforated pipe, two coaxial stamped slotted shirts and a layer of gravel in the space between them (Stamped slotted filter with gravel RRK. LLC "RosPromService" // www.ruspr.ru).

The downhole filter is characterized by the complexity of the design, the complexity of the formation of gravel packing and increased hydraulic losses.

Well-known filters consisting of a perforated body and a set of flat corundum circles (A.S. No. 981592 USSR, E21B 43/08, 1982) or plastic plates of different thicknesses (A.S. No. 1530759 USSR, E21B 43/08, 1989), located between the clamping and centering rings and forming slots for fluid movement.

The disadvantages of these filters are low throughput due to the low filtration area equal to the total width of the slots, as well as the complexity and complexity of the design.

Closest to the claimed one is a downhole filter containing a perforated frame, a drainage layer and filter elements in the form of polymer disks made of reinforced adhesive tape, on the adhesive side of which a layer of dispersed particles is fixed (Application No. 2011105457/03 (07747), the decision to issue from 11.01.12 )

The well filter adopted for the prototype has a limited service life due to the small volume of voids between the dispersed particles, in which impurities are retained, and is also difficult to manufacture.

The objective of the present invention is to increase operating time and reduce the complexity of manufacturing a well filter.

The specified technical result is achieved by the fact that in the well filter containing a perforated frame, a drainage layer and filter elements in the form of thin polymer disks with discrete particles on one of the bases, according to the invention, the discrete particles are polymer pins of the same height, oriented perpendicular to the plane of the base.

The polymer disks are mounted on top of each other so that the smooth base of one disk contacts the polymer pins of the adjacent disk. The smooth base of the polymer discs may be coated with adhesive to fix the polymer pins and maintain the size of the gaps between them.

The number of pins per unit surface area of the polymer disk determines the distance between them and, accordingly, the dimensions of the bore sections in the radial plane of the disk, that is, the fineness of cleaning the downhole filter.

The invention is illustrated by drawings, where figure 1 schematically shows a downhole filter, General view, section; figure 2 is a fragment of a cross section, a section aa of figure 1. The filter consists of a tubular frame 1 with perforations 2, a three-dimensional drainage grid 3 and polymer disks 4 with a central hole 5 (Fig. 1). On the upper base of the polymer disks 4 are randomly arranged with a gap 6 between each other polymer pins 7 of the same height, which are oriented perpendicular to the base. The preservation of the dimensions of the gaps 6 is achieved by means of clamping rings (not shown) mounted on the ends of the perforated frame 1. In the radial plane between the polymer pins 7, labyrinth-like slots 8 of variable width are formed (FIG. 2). The drainage three-dimensional grid 3 is designed to improve the communication of the labyrinth-like slots 8 with perforations 2.

Well filter works as follows.

The formation fluid flows from the well to the polymer disks 4 and is distributed along the labyrinth-like slots 8, when passing through which dispersed particles in the liquid are delayed between the polymer pins 7. The depth of penetration of particles into the labyrinth-like slots 8 depends on the ratio of particle sizes and gaps 6. If correctly the selected ratio, large particles accumulate outside the slots 8 with the formation of permeable structures that perform the function of an additional filter. The purified liquid from the slots 8 through a three-dimensional drainage grid 3 and perforation 2 enters the tubular frame 1 and is received by a submersible pump.

The use of thin polymer disks with polymer pins stochastically distributed in the radial plane but equally oriented perpendicular to it ensures a high specific filtration area and interconnected porosity of the filter elements. This, in turn, reduces pressure losses, increases the throughput, service life and dirt capacity of the downhole filter.

Claims (1)

A downhole filter containing a perforated frame and thin polymer disks with discrete particles attached to one of their bases, forming labyrinth channels between them, characterized in that the discrete particles are made in the form of polymer pins of the same height, oriented perpendicular to the plane of the base.

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