RU210405U1 - DEVICE FOR CLEANING THE FILTER AND THE FILTERED SPACE IN THE WELL - Google Patents

Abstract

The utility model relates to the oil and gas industry and can be used to clean well filters. The technical result of the utility model is the creation of a device, which is a body with holes into which jet nozzles are inserted. The housing is connected to the tubing string and has a thickening in the middle part, which provides a minimum gap between the housing and the filter wall. Due to the hydraulic resistance that occurs in the gap, a pressure drop is created, which is necessary for squeezing out the bridging agent from the behind-filter space. The effect of using the proposed device is achieved by accelerating the work (the technology of use is simplified) and improving the safety of work (the probability of sticking is reduced).

Description

The utility model relates to the oil and gas industry and can be used to clean well filters and behind-filter zones.

It is well known that during the operation of oil and gas wells, a gradual migration of the finely dispersed rock fraction (colmatant) of the productive horizon from the depth of the formation to the near-filter zone of the well occurs, as well as the accumulation of ARPD (asphalt-resinous and paraffin deposits) and salt deposits on the inner and outer surfaces of the filter.

This process leads to a deterioration in the filtration characteristics of the bottomhole formation zone and downhole filters directly, and, consequently, to a decrease in the inflow of formation fluid to the bottom of the well.

There are many methods and devices designed for cleaning (discolmatation) of filters and behind-filter zones using electrochemical, thermal and hydrodynamic processes (for example, [1], [2], [3]). The most common are cleaning methods that use the flow of fluid injected into the well and erode the bridging agent on the filter surface and in the behind-filter (between the well wall and the outer surface of the filter) space. Most of these devices contain isolating devices (packers) in the layout for more efficient direction of the fluid flow to the filter being cleaned and into the filter space, which makes it possible to remove the diluted bridging agent from the filter space.

A device [4] is known, which includes a housing with side holes for the outlet of the washing solution and sealing elements (packers) located above and below the said holes.

The technology of using such a device is quite technologically complex, and the presence of two sealing elements with landing directly on the walls of the casing string (filter) creates the risk of an accident (sticking) of the device or destruction of the sealing elements (packers) when the device needs to be moved inside the filter, as when preparing the device for operation, as well as during production.

The proposed design does not involve the installation of sealing elements (packers) that are in direct contact with the walls of the casing string (with the walls of the filter), and, therefore, is safer and more reliable in operation.

The specified technical result is achieved by the fact that in the well-known device for cleaning the filter and behind the filter space in the well, including a housing with side holes, in contrast to the prototype, the part of the body above the side holes is made with a thickening to provide hydraulic resistance and create a pressure difference between the lower and upper zones cleanable filter when circulating fluid. Jet nozzles are installed in the side openings in the device body, from which liquid jets flow, providing effective cleaning of the inner surface of the filter, filter holes, as well as liquefaction, softening of deposits in the space behind it.

The resulting technical result when using the proposed technical solution allows you to work on very long sections of the filter in horizontal wells.

In FIG. 1 shows the claimed device for cleaning the well filter and behind the filter space.

The proposed device includes a housing 1 with side holes into which jetting nozzles 2 are inserted. ). The body is connected to the drill or tubing string through adapter 5. The tightness of the device is ensured by sealing rings 3 and 4.

The device works as follows. The device is lowered into the well and placed in the upper part of the filter 6. The flushing liquid pumped from the surface passes through the jetting nozzles 2 and is divided into two streams. Most of the flushing fluid passes through the gap δ1 and creates a lower region with hydrodynamic pressure P1 and an upper region with hydrodynamic pressure P2<P1 due to pressure losses in the gap δ1. The rest of the flushing fluid passes through the filter into the behind-filter space and contributes to the rise of the bridging agent upwards, displacing it through the filter into the space between the filter and the drill or tubing pipes. Further, the bridging agent is carried out by the flushing fluid flow to the wellhead.

The jets flowing from the jetting nozzles 2 clean the inner surface of the filter, the holes and slots of the filter and, passing into the behind-filter zone, provide a force effect on the bridging agent, helping to reduce its viscosity.

Flushing (cleaning) can be carried out both with a continuous descent of the device, and in a stepped way.

Text links

1. RF patent 231987 dated March 10, 2008

2. RF patent 2281389 dated 10.08.2006.

3. RF patent 2347063 dated February 20, 2009.

4. RF patent 2112867 dated 06/10/1998.

Claims (1)

A device for cleaning the filter and behind the filter space in the well, including a body with side holes, characterized in that a thickening is made in the middle part of the body above the side holes, and jet nozzles are installed in the side holes.

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