RU2590924C1 - Well fluid cleaning filter - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention can be used for cleaning fluid in well bore from floating debris and suspended particles. Device includes a slotted pipe, screen, valve, sealing device of annular space of well, coupling, housing and cylindrical bottom. Screen is arranged around part of slotted pipe with slots. Slotted pipe and housing are mounted by lower parts respectively inside and outside cylindrical bottom. Slotted pipe is arranged inside housing and is connected in upper part above slots with housing by struts. Valve used is a plate-type valve. Valve and coupling are arranged in upper part of slotted pipe. Sealing device of annular space of well is placed on outer part of cylindrical bottom. Ratio of width of slots of pipe to with of screen is equal to (3.5-5):(0.7-3.5).

EFFECT: higher efficiency of cleaning well fluid.

1 cl, 1 dwg

Description

The invention relates to the oil industry and may find application in cleaning fluid in a wellbore from floating debris and suspended particles.

There are a large number of sub-pump well filters designed to clean the well fluid entering the pump (see, for example, filter sub-pump anti-sand patent of the Russian Federation No. 2222691, CL EV 43/08, EV 03/18, publ. 01.27.2004). Filters connected to the pump are not able to clean the well fluid in the well volume.

A device for cleaning a well is known, which includes a ruff placed on a tubing string and a filter and a check valve located inside the tubing string in the interval above the filter. The filter is made in the form of three perforated pipes concentrically placed and plugged from below, the outer of which has a nominal diameter of 88.9 mm, the middle one is 73.0 mm and the inner one is 60.3 mm, while the outer pipe is perforated with holes of 5 mm diameter, the middle one holes with a diameter of 4 mm and the inside with holes with a diameter of 2 mm (RF patent No. 2467159, CL EV 37/02, publ. 20.11.2012).

Known filter after placement in the well requires the mandatory application of circulation of the wellbore fluid through the filter. In this case, an uncontrolled and very fast clogging of the filter openings occurs and its operation ceases.

Closest to the proposed invention in technical essence is a device for cleaning fluid in a wellbore, including a garbage storage container, a valve, a bottom plug and a filter settler, and a slot nozzle located above a garbage storage container, couplings, and lower and upper rubber umbrellas sealants of the annulus of the well. The valve is located in the plug and has a seat diameter larger than the maximum size of the contaminants in the well, the filter sump is made with longitudinal slots and closed with a fine mesh mesh with a mesh size less than the minimum size of the contaminants trapped in the well, the lower umbrella-shaped rubber sealant of the annulus is located outside the garbage storage container between two couplings at a distance from the plug equal to 15-20% of the total length of the device, the upper umbrella-shaped rubber sealant of the annulus placed outside the garbage storage container between two couplings at a distance from the upper end of the device equal to 15-20% of the total length of the device, the slotted nozzle is made with longitudinal slots wider than the maximum size of contaminants in the well.

When cleaning the well fluid, the device is lowered into the well and lifted from the well. When rising from the well, the borehole fluid passes inside the device, is filtered through slots and the mesh and goes into the well. Pollution is delayed by cracks and fine mesh (RF patent No. 2474672, CL ЕВВ 27/00, ЕВВ 43/08, publ. 02/10/2013 - prototype).

A disadvantage of the known device is the need for organizing the flow of the well fluid through the device, in which slots and fine mesh quickly become clogged. As a result, the device ceases to perform filtering properties, and the well fluid begins to flow between the device and the walls of the well.

In the proposed invention solves the problem of more efficient cleaning of the well fluid.

The problem is solved in that the filter for cleaning the borehole fluid, including a slotted nozzle, a mesh, a valve, a sealant of the annular space of the well and a sleeve, according to the invention, further comprises a housing and a cylindrical bottom, while the mesh is placed around a portion of the slotted nozzle with slots, a slotted nozzle and a housing fixed by the lower parts, respectively, inside and outside the cylindrical bottom, the slotted nozzle is located inside the housing and is connected in the upper part above the slots with the housing by struts, as a valve a poppet type valve is connected, the valve and the coupling are located in the upper part of the slotted nozzle, and the annular sealant of the well is located on the outer part of the cylindrical bottom, while the ratio of the width of the slots of the nozzle to the width of the mesh cell is (3.5-5) :( 0.7 -3.5).

SUMMARY OF THE INVENTION

In oilfield wells, the need periodically arises to clean the fluid in the well. Contaminants accumulate in the well and a situation occurs when the pump filter becomes clogged with contaminants, the pump stops working. All filters associated with the pumps are not able to clean the well fluid. These filters are intended only for cleaning the fluid entering the pump.

To clean the well fluid, several technical solutions have been proposed, the main disadvantage of which is the need to pass the entire volume of the well fluid through the filter. In this case, contaminants accumulate inside the filter and clog the filter mesh and slots. Gradually, the filter stops filtering the liquid. Well fluid begins to flow between the filter and production string. Cleaning efficiency is reduced. In the proposed invention solves the problem of more efficient cleaning of the well fluid. The problem is solved by the well fluid cleaning filter shown in FIG. one.

In FIG. 1, the following designations are adopted: 1 - slotted pipe, 2 - mesh, 3 - valve, 4 - annulus sealant, 5 - coupling, 6 - body, 7 - cylindrical bottom, 8 - struts. Slotted pipe 1 is provided with slots 9.

The mesh 2 is placed around the part of the slotted nozzle 1 with slots 9. The slotted nozzle 1 and the housing 6 are fixed by the lower parts inside and outside the cylindrical bottom 7. At the same time, the slotted nozzle 1 is located inside the housing 6 and is connected in the upper part above the slots 9 with the housing 6 struts 8, representing a flat plate. As valve 3, a poppet type valve is used. The valve 3 and the coupling 5 are located in the upper part of the slotted nozzle 1. The annular sealant 4 is located on the outside of the cylindrical bottom 7. Rubber, polyurethane, nylon, and the like are used as a sealant. rings. The ratio of the width of the slots 9 of the pipe 1 to the width of the mesh cell 2 is (3.5-5) :( 0.7-3.5).

The cylindrical bottom 7 together with the lower part of the slotted nozzle 1 and the housing 6 form a container for collecting contaminants. The upper part between the slotted pipe 1 and the housing 6 is open for the flow of well fluid between the struts 8. The coupling 5 is designed to connect the filter to the traction body such as a cable, cable, wire, etc. or for connecting to a string of pipes, for example tubing.

The filter for cleaning the well fluid works as follows.

When the filter is lowered down on the traction body or pipe string, the borehole fluid flows through the inner space of the cylindrical bottom 7, the slotted nozzle 1, the poppet valve 3, which opens under the action of the pressure of the fluid, the coupling 5 and enters the space above the filter. The annular seal 4 slides along the production casing.

When lifting the filter up, the poppet valve 3 closes. The annular seal 4 slides along the production string and prevents the flow of fluid between the production casing of the well and the filter. Downhole fluid flows past the struts 8 into the space between the slotted pipe 1 and the housing 6, is filtered through the mesh 2 and the slit 9, flows into the slotted pipe 1 and exits the filter through the inner space of the cylindrical bottom 7.

The contaminants are retained by the grid 2 and, when the filter is stopped or slowed down, fall down to the cylindrical bottom 7. Moreover, the proposed filter design provides alternating movements of the wellbore fluid through slots 9 and the grid 2, which in turn helps to separate the contaminants from the grid and settle them down onto the cylindrical bottom. The selected ratio of the width of the slots 9 of the pipe 1 to the width of the mesh 2 is equal to (3.5-5) :( 0.7-3.5) provides the best cleaning of the mesh and the resumption of the filter.

As an example, the ratio of the width of the slots 9 of the pipe 1 to the width of the mesh 2 can be taken as (3.5 mm - 5 mm) :( 0.7 mm - 3.5 mm).

The filter has been tested in borehole conditions and has shown high efficiency. The fluid in the well is completely free from contaminants larger than 0.7 mm.

The use of the proposed filter will improve the cleaning efficiency of the well fluid.

Claims (1)

1. A well fluid cleaning filter including a slotted nozzle, a mesh, a valve, an annulus sealant and a sleeve, characterized in that it further comprises a housing and a cylindrical bottom, the mesh being placed around a portion of the slotted nozzle with slots, the slotted nozzle and the housing are fixed with lower parts, respectively inside and outside the cylindrical bottom, a slotted nozzle is located inside the housing and is connected in the upper part above the slots with the housing by struts, the valve is used as a valve type, the valve and the coupling are located in the upper part of the slotted nozzle, and the annulus sealant is placed on the outer part of the cylindrical bottom, while the ratio of the width of the slots of the nozzle to the width of the mesh cell is (3.5-5) :( 0.7-3 ,5).

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