RU75215U1 - FILTER WELL - Google Patents

Abstract

The utility model relates to the oil and gas industry and is used in oil production by well pumps to filter well fluid from mechanical impurities (sand, sludge) and gas. The device contains a perforated pipe with a sleeve and a metal mesh that covers the outer surface of the pipe. The perforated pipe on its outer surface has a wire frame representing a spring with a certain winding pitch. A filter element is fixed to this frame, several are installed along the length of the perforated pipe of such elements, which are fixed in the centralizers. A receiving pipe is installed inside the perforated pipe, the lower end of which is made with a bevel and is located below the filter elements, and the upper end extends into the sleeve. In the case of clogging of the filter elements, a valve is provided representing a split ring that closes the holes in the perforated pipe.

Description

The utility model relates to the oil and gas industry, is used in oil production by well pumps to filter well fluid from mechanical impurities (sand, sludge) and gas. Known designs of filters containing a perforated pipe and mounted on it a wire mesh (filter element) [1]. The disadvantages of the known design are:

- poor performance of the filter element due to clogging of the mesh with mechanical impurities (sand, sludge) during operation of the downhole pumping unit.

- the metal mesh during the descent into the well due to friction against the walls of the casing may be destroyed;

- when the filter is located on an inclined section, its throughput decreases due to the adherence of the metal mesh to the walls of the well.

The closest prototype is a downhole filter for filtering the product extracted from oil, water and gas wells. [2] The device includes a perforated pipe with a sleeve and a metal mesh that covers the outer surface of the perforated pipe. The perforated pipe on its outer surface is made with ribs arranged in a spiral with a pitch.

The disadvantages of the prototype are:

- poor filter performance;

- decrease in filter capacity on an inclined section of the well due to the fit of the filter to the wall of the casing;

- the inability to separate gas;

- the impossibility of the filter in case of clogging of the filter element.

The technical task of the utility model is to increase the efficiency of the downhole filter and, as a result, increase the reliability of the downhole pump installation.

The technical result is achieved by the fact that in the downhole filter containing a perforated pipe with a sleeve and a filtering metal mesh, covering the outer surface of the perforated pipe in which, according to a utility model, several filtering elements are installed along the length of the perforated pipe, which represent a metal mesh fixed in a frame and installed in centralizers, a receiving pipe is installed inside the perforated pipe, the lower end of which is made with a bevel and is located below the filter element ntov, and the upper end goes into the sleeve. At the level of the lower end of the receiving pipe, holes are made on the perforated pipe, which are closed by a split ring. In figure 1., (a general view of the downhole filter is shown, which consists of a perforated pipe 1, a sleeve 2, filtering elements (metal mesh) 3, centralizers 4, a spring frame 5, a receiving pipe 6, a split ring 7, and a plug 8.

The operation of the device is as follows. The downhole filter is connected through a threaded connection to the pump unit and is lowered into the well on the tubing string.

The centralizers 4, in which the filter element (metal mesh) is installed, have an outer diameter that allows you to center the downhole filter in the casing string.

The produced fluid passes through the filter element (mesh) 3, through the holes of the perforated pipe, then the liquid changes direction rushing towards the open end of the receiving pipe 6. The impurities present in the composition of the liquid due to higher density and change

flow directions settle onto plug 7, and the purified liquid enters the intake of the pump unit.

When the filter element is clogged, a vacuum is created in the perforated pipe due to the operation of the pump unit, and the split ring is squeezed from the wall of the perforated pipe, giving access to the passage of fluid to the intake of the pump unit without filtration. Thus, the well pump can work with unfiltered fluid for some time, pump operation without fluid access is excluded, which can lead to breakdown of the pump.

When installing the downhole filter on an inclined section of the well, centralizers whose outer diameter is larger than the outer diameter of the filter element do not allow the filter element (mesh) to come into contact with the casing wall, thus, there is no decrease in filter capacity.

Technical and economic benefits include:

1. Well filter allows you to increase the reliability of the whole pump installation.

2. If there is a large amount of impurities in the produced fluid, it is possible to install several downhole filters in series.

3. The presence of a centralizer with an outer diameter greater than the diameter of the filter element allows the installation of a downhole filter on an inclined or horizontal section of the well, without reducing its throughput.

Information sources:

1 Gavrilko V.M. etc. Drill hole filters. - M .: Nedra, 1976, p. 8, 9.

2 RF Patent 2133820, MKI E21B 43/08, 1997

Claims (3)

1. A downhole pump filter containing a perforated pipe with a sleeve and a filtering metal mesh covering the outer surface of the perforated pipe, characterized in that several filter elements are placed along the length of the perforated pipe, representing a metal mesh fixed in the frame and installed in centralizers. 2. The filter according to claim 1, characterized in that a receiving pipe is installed inside the perforated pipe, the lower end of which is made with a bevel and is located below the filter elements, and the upper end extends into the sleeve. 3. The filter according to claims 1 and 2, characterized in that a split ring is installed on the inner surface of the perforated pipe above the lower end of the receiving pipe, overlapping the holes in the perforated pipe.