RU74956U1 - SELF-CLEANING FILTER TO PREVENT PUMP BLOCKING - Google Patents

Abstract

A self-cleaning filter to prevent pump clogging, installed on the tubing string and including a coupling, an adapter for connecting to a plunger carrying a pressure valve in its cavity, and a cylinder connected to the filter, characterized in that the filter is a prefabricated structure, equipped with a pressure valve located inside, equipped with inlets with a mesh protecting them and made with the possibility of a vacuum at the pump intake, causing water hammer for self-cleaning mesh.

Description

The utility model relates to the oil and gas industry, namely to the construction and operation of oil and gas wells, and can be used in oil production to increase the duration of sucker rod pumps by protecting them from clogging by particles contained in the well fluid.

Prerequisites for creating a utility model.

Analysis of the current level of technology in this field showed the following.

Currently, 90% of the operating fund of NGDU Elkhovneft is operated by sucker rod pumps (SHGN). In practice, the intake of SHGN is equipped with a protective filter, which is a perforated pipe with a welded plug made from used tubing (tubing). A connecting thread is cut in the upper part of the pipe, which corresponds to the internal thread in the extreme lower part of the SHGN. During long-term operation of the well, these filters become clogged with abrasive, mechanical particles, scale from the tubing and production casing, as a result of which the feed is “interrupted” and the SHG fails.

In the process of filtering formation fluid through the filtering surface, increased filtration rates occur in the area of perforation holes, as a result of which the filter cannot fulfill the function of reliable retention of mechanical particles in the zone of the reservoir.

Significant disadvantages of this design is the lack of a cleaning system, and therefore, as the mechanical impurities settle, part of its area is excluded from the filtration mode at the bottom of the filter, which is reflected

on the hydrodynamics of fluid lifting, as well as the inability to clean the filter from mechanical impurities.

Well-known equipment filters, including a nozzle with radial holes and filtering elements closing these holes in the form of a mesh of metal wire (AS USSR No. 1076572 and No. 1645470, class E21B 43/08), in the form of metal rings and disks with grooves (AS USSR No. 1530759 and No. 1587179) or in the form of cermet bushings (AS USSR No. 1550103 and No. 1161692).

Their disadvantages are the accumulation of sand and solid particles during operation and the fact that the filter elements are not cleaned of sediment, quickly clogged by particles contained in the well fluid. This creates additional hydraulic resistance to fluid flow.

Well pump filters are known in which the filter elements are made of elastic material that deform under the influence of a changing pressure drop and retain their original throughput (AS USSR No. 1472648).

However, they are difficult to manufacture and ineffective in the conditions of deposition of sticky paraffin-resinous substances.

Well pump filters are also known, in which the filter elements are made in the form of springs or equipped with spring shock absorbers and elastic limiters, which ensure their self-cleaning under the influence of mechanical impulses arising from the cyclic extension of the pipe string during pump operation (AS USSR No. 439594 and No. 1523654).

They also have a complex structure and are ineffective in the conditions of the deposition of sticky paraffin-resinous substances.

The objective of this utility model is to improve the design of a self-cleaning filter to prevent clogging of pumps in order to improve the cleaning of the well from sand, sludge and other mechanical impurities, resulting in an increase in the quality of the produced oil.

The problem is solved by the use of a self-cleaning filter to prevent clogging of the pumps.

A self-cleaning filter to prevent pump clogging is installed on the tubing and includes a sleeve, an adapter for connecting to the plunger, in which the discharge valve, cylinder and filter are located.

The essence of the utility model is that the self-cleaning filter is a prefabricated structure, lowered into the well on the tubing string, connected to the cylinder and consisting of a filter with inlet openings and a pressure valve inside the filter, as well as a grid protecting the inlet openings.

The principle of operation of the self-cleaning filter is that as the protective mesh becomes clogged during the upward movement of the SHG plunger, a vacuum appears at its intake, as a result of which the cylinder rises, a water hammer occurs, and the mesh is cleaned of contaminants.

The proposed self-cleaning filter is illustrated by the drawing in Fig.1.

A self-cleaning filter to prevent clogging of pumps is installed on the tubing string 1 and includes a sleeve 2, an adapter 3 for connecting to the plunger 4 with a pressure valve 5 (ball with a seat), cylinder 6 and a filter 8 with a pressure valve 7 (ball with a saddle and spring moreover, the saddle is made in the form of a fitting) and inlets with a protective mesh 9.

Self-cleaning filter to prevent clogging of the pumps works as follows.

During underground or ongoing well repair, the device is installed at the SHGN reception and is lowered into the well at the tubing string 1. Upon completion of the repair work, the well is put into operation. The produced liquid enters the filter cavity 8 through the inlet openings with a protective net 9. In the working position, the forced valve 7 is open, therefore, the produced liquid freely enters the cylinder 6 under pressure

the plunger 4 through the discharge valve 5. When the SHG plunger 4 moves up, the produced fluid, which is in the plunger 4, enters the tubing 1, the discharge valve 5 closes, and therefore a vacuum appears in the cylinder 6, which remains in place. Next, the cylinder 6 with the filter 8 moves up and, reaching the bottom of the plunger 4, causes a water hammer, and the protective mesh 9 is cleaned of dirt. When the plunger 4 moves downward, the discharge valve 5 opens, the cylinder 6 and the filter 8 with the forced valve 7 return to their original position, the produced fluid again enters through the inlet openings with a protective mesh 9 into the filter cavity 8 and, then, through the forced valve 7 into the cylinder 6. The described process is cyclical.

The technical result of the use of a self-cleaning filter is the use of hydrodynamics of the produced fluid coming from the formation through the inlet openings with a mesh, which allows holding mechanical impurities and sand without losing the filtration properties of the device and, as a result, improving the quality of the produced fluid.

In comparison with existing analogues, the use of the proposed device has the following advantages: there are no mechanical barriers on the way of the fluid movement, i.e. hydraulic losses to overcome the resistance to flow movement are minimized, the risk of clogging and jamming of pumps is reduced, the reliability and overhaul period of the well are increased. In addition, the use of a self-cleaning filter allows you to operate a periodic well stock with low dynamic levels in a constant mode.

Claims (1)

A self-cleaning filter to prevent pump clogging, installed on the tubing string and including a coupling, an adapter for connecting to a plunger carrying a pressure valve in its cavity, and a cylinder connected to the filter, characterized in that the filter is a prefabricated structure, equipped with a pressure valve located inside, equipped with inlets with a mesh protecting them and made with the possibility of a vacuum at the pump intake, causing water hammer for self-cleaning mesh.