RU2514057C1

RU2514057C1 - Well screen

Info

Publication number: RU2514057C1
Application number: RU2012152888/03A
Authority: RU
Inventors: Камил Рахматуллович Уразаков; Сергей Васильевич Смольников; Валерий Петрович Жулаев; Роман Васильевич Сахнов; Дмитрий Михайлович Деменин
Original assignee: ООО "РН-УфаНИПИнефть"
Priority date: 2012-12-06
Filing date: 2012-12-06
Publication date: 2014-04-27

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: proposed device comprises metal pipe with holes stopped by plug from below and by coupling from above and cylindrical filter element arranged there inside and aligned therewith. Pipe top section with holes is composed by a separate section with no inside filter element coated with screen on the outside. Said section houses rubber diaphragm composed by the sleeve. Diaphragm thickness decreases in vertical line parallel with metal pipe axis and aligned with elongated hole major axis. Proposed filter is composed of sections connected by couplings. Pipe top section with holes is connected with pump on one side or with shank by coupling and with downstream filter section on opposite side.

EFFECT: higher reliability, simplified design, increased MTBR.

3 cl, 5 dwg

Description

The claimed invention relates to the oil industry and can be used in the operation of oil, gas and water wells.

Known sand filter, consisting of concentrically located outer, intermediate and inner pipes, the latter is equipped with holes, as well as sub. In this case, the inner wall of the pipe is equipped with a filter mesh located inside it, made in the form of a screw and attached opposite the holes made along a helical line. The outer and inner pipes in the upper part are interconnected by tangential pipes, and the inner and intermediate pipes in the lower part are also connected by tangential pipes, but oppositely oriented relative to the first. The annular gap between the intermediate and inner pipes in the upper part, as well as the upper and lower parts of the inner pipe, are equipped with plugs, the outer pipe in the upper part is equipped with elastic elbows and in the lower part with a plug (Pat. RF No. 2158358, E21B 43/08, 1999).

The design disadvantages of this filter are abrasion and destruction of the filter mesh due to its blockage and slow cleaning of mechanical impurities, as well as a low separation coefficient of mechanical impurities.

A well-known well filter, consisting of concentrically located outer, intermediate and inner pipes, the last two provided with holes and in the upper part are interconnected by a pipe, while the outer pipe is connected to the intermediate pipe by annular plugs (US Pat. RF No. 2305756 E21B 43/08, 2007).

The disadvantage of this filter is the complexity of its design, which leads to increased complexity during its subsequent assembly and operation. In case of clogging of the filter element, the liquid supply stops, which necessitates the replacement of the filter and, as a result, the pump stops working.

Closest to the claimed invention according to the technical result and the problem to be solved is a downhole filter (US Pat. RF No. 2355876, E21B 43/08, 05/20/2009), consisting of concentrically located outer and inner pipes. In this case, the outer metal pipe is provided with holes, its upper part is equipped with a sleeve in which a spring-loaded valve is installed, and the lower part is equipped with a plug. Inside the metal pipe there is a filter element made in the form of sections of internal pipes, the alignment of which is provided by centralizers.

However, this filter is not effective enough, as it has a low degree of reliability due to the complex valve design, which increases its cost from manufacture. The presence of a ball with a spring requires the use of expensive corrosion-resistant materials, which could ensure the failure-free operation of the valve assembly throughout the life of the well filter. In addition, a spring working in an environment of aggressive well fluid is a weak link in the filter design, which reduces the overhaul period of the pump.

The task to which the invention is directed is to increase the efficiency of the downhole filter while reducing labor costs for its manufacture due to the technical result provided - simplifying its design and increasing the reliability of operation, as well as increasing the overhaul period of the pump equipped with a filter. The increase in the overhaul period of the pump occurs for a period equal to the period of its operation in the conditions of a clogged filter element, due to the possibility of liquid passing through the upper section when the filter element is clogged.

This problem is solved in that the downhole filter, which includes a metal pipe with holes, provided with a plug at the bottom, and a clutch on top of the sleeve, and a cylindrical filter element coaxial with it, differs in that the upper part of the metal pipe with holes, made as a separate a section that does not have a filter element inside is covered with a mesh on the outside and inside contains a rubber diaphragm made in the form of a sleeve, the thickness of which is reduced along a vertical line parallel to the llicheskoy tubes and coincident with the major axis of the elongated holes formed in the upper portion of the metallic tube.

The filter is made in the form of sections connected by couplings, the number of which is determined by the operating conditions. The upper part of the metal pipe with holes, made in the form of a separate section that does not have a filter element inside, is connected on one side to a pump or shank with a coupling having an external thread in the upper part and an internal thread in the lower, and on the other hand, with a female thread coupling - with the filter section below.

The downhole filter circuit is shown in the figures.

Figure 1 - Well filter.

The dashed lines in the upper part of the metal pipe, made in the form of a separate section, show the location of the elongated holes, the elongations are made along a separate section of the metal pipe.

Figure 2 - Upper individual section of the downhole filter, with a sleeve.

The dashed lines in the upper part of the coupling, as well as in the upper separate section of the downhole filter, indicate the presence of an external thread. The coupling has an external thread at the top and an internal thread at the bottom.

Figure 3 - Fragment of the upper individual section of the downhole filter.

Figure 4 - Rubber diaphragm before and after the gap.

Figure 5 - A fragment of a cross section of a rubber diaphragm, the thickness of which is reduced along a vertical line parallel to the axis of the metal pipe and coinciding with the major axis of the elongated holes made in the upper part of the metal pipe (representing the upper separate section of the downhole filter).

The letter A in figure 1 shows a fragment of the downhole filter, subsequently enlarged and shown in figure 2.

The letter B in figure 2 shows a fragment of the upper individual section of the downhole filter, subsequently enlarged and shown in figure 3.

The letters B, D in FIG. 3 indicate the cross section of the hole in the upper part of the metal pipe and the fragment of the diaphragm.

The letter D in figure 4 shows a fragment of a cross section of a rubber diaphragm, the thickness of which is reduced along a vertical line parallel to the axis of the metal pipe and coinciding with the major axis of the elongated holes made in the upper part of the metal pipe, subsequently enlarged and shown in figure 5.

The downhole filter contains a metal pipe 1 with holes 2 in its upper part, made in a separate section, elongated holes 2, extensions are made along the metal pipe, filter element 3, couplings with internal threads 4, plug 5. In the lower part of the metal pipe 1 the shape of the holes is not critical.

A mesh 6 is installed on the outer surface of the upper separate section of the metal pipe 1, which does not have a filter element inside, and a rubber diaphragm 7 is installed on its inner surface, the thickness of which is reduced along a vertical line 9 parallel to the axis of the metal pipe 1 and coinciding with the major axis of the holes 2 elongated shape.

The fluid extracted from the well moves along the internal section 8 of the device to receive the pump. The coupling 10, having an external thread in the upper part and an internal thread in the lower, connects the upper part of the metal pipe 1 to the pump or shank.

The downhole filter is mounted under the downhole pump installed in the well on the tubing string, or at the lower end of the liner.

Well filter works as follows.

The fluid produced from the well, passing through the holes of the metal pipe 1 and through the surface of the filter element 3, is cleaned of mechanical particles and then, along the internal section 8 of the device, is received by the pump. The number of filter sections is determined by the operating conditions. Clutches 4 provide a connection between the filter sections, and a clutch 10, having an external thread in the upper part and an internal thread in the lower, connects the upper part of the metal pipe 1 to the pump or shank. The plug 5 prevents the passage of fluid through the open end of the filter element 3. As the surface of the filter element 3 becomes clogged, the pressure at the pump inlet increases. Upon reaching the calculated value of the pressure drop, the rubber diaphragm 7 is destroyed, the thickness of which is reduced along the vertical line 9 parallel to the axis of the metal pipe 1 and coinciding with the large axis of the elongated holes 2 made in the pipe 1. It is the indicated decrease in the thickness of the rubber diaphragm 7 that allows it destruction and opening as a double-leaf door, without tearing off pieces of fragments of the rubber diaphragm 7 and clogging of the pump valves or the clearance of the plunger pair; moreover, the fluid enters the pump intake, bypassing the filter element 3, passing through the holes 2 and the rubber diaphragm 7 destroyed along the line 9. The mesh 6 protects the rubber diaphragm 7 from destruction during the descent of the filter into the well, as well as the reception of the pump from large mechanical particles .

The claimed invention can be used in the oil, gas, mining and other industries when pumping from wells various kinds of liquid media with mechanical impurities.

Claims

1. A downhole filter, comprising a metal pipe with holes, provided with a plug at the bottom and a clutch on top, and a cylindrical filter element coaxial with it inside the metal pipe, characterized in that the upper part of the metal pipe with holes, made in the form of a separate section that does not have inside the filter element, outside is covered with a mesh, and inside contains a rubber diaphragm made in the form of a sleeve, the thickness of which is reduced along a vertical line parallel to the axis of the metal pipe and matching with a large axis of elongated holes made in the upper part of the metal pipe.

2. The filter according to claim 1, characterized in that it is made in the form of sections connected by couplings, the number of which is determined by the operating conditions.

3. The filter according to claim 2, characterized in that the upper part of the metal pipe with holes, made in the form of a separate section that does not have a filter element inside, is connected on one side to a pump or shank with a coupling having an external thread in the upper part and an internal thread in the lower, and on the other hand, with a female thread coupling, with a filter section located below.