RU2553696C1 - Device for depression-wave well cleaning - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device contains installed on the sucker-rod string the reception branch pipe in the form of a feather, the check dish-shaped valve, the check ball valve, the filter, the hydrodynamic valve, the throttle coupling, the hydrostatic valve, the knock-off valve; the valve with compulsory operation. The hydrostatic valve includes a plunger with cross-over holes and is fitted with sealing rings, and its internal cavity is fitted with circulating microvalves . The hydrodynamic valve includes the housing, the adjusting nut, the spring, the thrust, the conical valve and the branch pipe. The housing of the lower check dish-shaped valve is implemented as a centraliser with the maximum allowable diametrical sizes for the casing string of the specific well.

EFFECT: reliability and quality of cleaning of the bottomhole zone of formation and the well face with ensuring of the device operability in the inclined directed and horizontal wells and adjustability of cleaning process.

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Description

The present invention relates to the oil industry, namely to the operation and repair of wells, and can be used to clean the bottom of the formation and bottom of the well from sludge, sand plugs, scale, sedimentation deposits and other items that complicate oil production.

From the analysis of the prior art of such equipment, an implosion device for cleaning wells is known, comprising a packer device located on the tubing string between the trap casing and the cleaning valve and made with a through channel and a blind axial channel in which the end of the pipe for supplying reagent is located and which is communicated with the annulus (RF patent No. 2160825, class E21B 37/00. "Implosion device for cleaning wells", publ. 12/20/2000).

The disadvantages of the known device are:

- design complexity;

- limited (small volume) of the prefabricated node, which causes the need for additional tripping and lifting operations;

- volley inflow of sludge into the sludge trap, which reduces the efficiency of its filling, since there is no regulation of the flow rate;

- uncontrollability of the process of dumping sludge when cleaning the face.

A device for cleaning wells is known, comprising a filter installed on a tubing string, a check valve, a hydrostatic assembly, including a stem with bypass holes and shear pins, a relief valve and an overpressure bleed assembly, a throttling sleeve (fitting) for regulating the cleaning process moreover, the tubing string is a container for collecting sludge, sand, etc. while the adjustable hydraulic choke is equipped with a set of special nozzles (RF patent No. 43907, class E21B 37/00. "Adjustable hydraulic choke", publ. 02/10/2005).

The disadvantages of this device include:

- the impossibility of using it in directional and horizontal wells;

- the operation of the device is based on a simple "suction" of sludge, sand, etc., although adjustable.

It is also known a device for cleaning wells, comprising a housing, a hollow rod, a locking element made in the form of a cylinder overlapping the radial holes of the hollow rod, having a gap for fluid flow and sealing elements made also in the hollow rod, with the possibility of removal by the fluid stream after actuation purifier. In addition, in the housing above the locking element there is a hole with a collar in which the washer is installed (patent No. 113300, class E21B 37/00. "Well cleaner", publ. 02/10/2012).

The disadvantages of this device are:

- unregulated process;

- the work is based on a simple “suction” of formation fluid;

- it is possible to plug the tubing string.

The aim of the invention is:

- improving the operational reliability and quality of cleaning the bottom-hole zone of the formation and the bottom of the well, - ensuring the operability of the device in directional and horizontal wells,

- improving the quality of cleaning the bottom-hole zone of the formation due to the integrated effect on the formation fluids both in the depression mode and in the mode of microwave exposure, since such a complex effect significantly increases the efficiency of cleaning the bottom of the well,

- the ability to extract the drilling fluid filtrate and call the inflow from the reservoir (development) after drilling the well without additional tripping, adjustable cleaning process (on and off) in a strictly specified interval of the wellbore.

The use of centralizers in the layout makes it possible to simplify the work with the device due to the absence of a packer assembly in the layout; the centralizer performs its function, reducing the annular cross-sections, without significant loss of device efficiency.

The goal is achieved by the proposed device of the depression-wave cleaning of the well, which includes a receiving pipe in the form of a pen installed on the column of pump pipes, a poppet check valve, a ball check valve, a filter, a hydrodynamic valve, a butterfly valve, a hydrostatic valve, including a plunger with bypass openings and whipping valve. At the same time, a forced-action valve is installed in the upper part of the device, which opens when the device rests in the bottomhole plug and closes when the device is lifted, in addition, the hydrostatic valve plug is equipped with o-rings located above the bypass holes, and the bypass holes in it are made at an acute angle relative to the longitudinal axis of the device, in the direction facing the wellhead, while the inner cavity of the hydrostatic valve is equipped with drain microvalves, and a dynamic valve placed above the filter consists of a housing, an adjusting nut, a spring stop, a spring, a cone valve and a nozzle and initiates adjustable pulses of fluid pressure in a wide frequency range, while the lower check valve housing is made in the form of a centralizer with the maximum allowable diametrical dimensions for casing string of a particular well.

The fundamental difference between the proposed device and the existing designs of cleaners and chokes is a hydrodynamic valve that provides the integrated effect of a pulsating depression on the formation fluid in order to better clean the bottom-hole formation zone and the bottom of the well, in addition, it is possible to control pressure pulsations in a wide frequency range.

The device depressive-wave cleaning of the well shown in the drawings:

FIG. 1 - general view (layout);

FIG. 2 - hydrostatic valve (HSC) - longitudinal section;

FIG. 3 - hydrodynamic valve (GDK) - longitudinal section;

FIG. 4 - valve with forced actuation.

The device of the depression-wave cleaning of wells (Fig. 1) consists of the following main nodes: 1 - pen; 2 - poppet check valve, the body of which can be made in the form of a centralizer; 3 - ball check valve (spring-loaded); 4 - filter; 5 - hydrodynamic valve (GDK); 6 - throttle clutch (DM); 7 - hydrostatic valve (HSC); 8 - valve with forced actuation; 9 - tubing (tubing); 10 - nozzles, 11 - knocking valve.

The hydrostatic valve (HSC) shown in FIG. 2, consists of the following main components: 1.7 - valve body; 2.7 - guide bush; 3.7 - plunger; 4.7 - channels in the plunger; 5.7 - valve piston; 6.7 - microvalves drain; 7.7 - sealing rings; 8.7 - sub.

The hydrodynamic valve (HDC) shown in FIG. 3, consists of the following nodes: 1.5 - housing GDK; 2.5 - adjusting nut; 3.5 - spring stop; 4.5 - spring; 5.5 - conical valve; 6.5 - pipe.

The forced-action valve shown in FIG. 4, consists of the following nodes: 1.8 - KPS case; 2.8 - coupling; 3.8 - stock-sub; 4.8 - saddle; 5.8 - nut; 6.8 - support ring; 7.8 - O-ring.

Device depressive wave cleaning of wells works as follows. The device of the depression-wave cleaning of wells goes down into the well until it stops in a cork (sand, sludge, etc.) in the direction indicated in FIG. 1 layout.

When the device is lowered on the tubing string - 9, the internal cavity of the pipes remains under atmospheric pressure. At the moment of touching the bottom of the plug device, the annular (annular) space communicates with the internal cavity of the NTC through the actuation of the valve with forced actuation of -.8 and the hydrostatic valve of 7, while due to the pressure differential between the annulus and the inner cavity of the tubing string-9, the annulus is intensively supplied liquids (reservoir fluid) together with sludge, sand mud, etc. into the cavity of the tubing string, which is then held by check valves - 2 and 3. In this case, when the formation fluid passes through the hydrodynamic valve (GDK) - 5, pressure pulsations are initiated due to oscillatory movements of the spring-loaded shut-off element (cone valve), see Fig. 3. The hydrodynamic valve (GDK) - 5, thus, carries out the buildup ("pacing") of sludge particles (colmatant, etc. in the pore space with subsequent intensive removal of them into the receiving cavity of the tubing) - 9.

Hydrodynamic valve - 5 allows you to use the energy of the inner cavity of the tubing string more efficiently and with greater productivity. The operation of the hydrostatic valve - 7 (Fig. 2) is to open (message annulus with the internal cavity of the tubing string - 9) at the moment of touching (unloading) of the device as a whole. In this case, the passage channels inclined at an angle of 45 degrees provide a smoother (with less hydraulic resistance) flow of the formation fluid with sludge, sand, mud, etc.

To increase the effective functioning of the device as a whole, the throttle clutch - 6 is equipped with fittings with different diameters of the passage channels.

Using the claimed invention will ensure:

- more “deeper” and better cleaning of the bottom-hole formation zone and the bottom of the well;

- more effective cleaning of the bottomhole formation zone and the bottom of the well by adjusting the frequency of pressure pulsations in a wide range;

- removal of the filtrate of the drilling fluid call inflow from the reservoir (development) after drilling wells without removing the device from the well.

The device is easy to manufacture, reliable in operation, provides a stable positive effect.

The device of the depression-wave cleaning of wells was tested in the field and confirmed its high efficiency.

Claims (1)

A device for depression-wave cleaning of a well, including a receiving nozzle in the form of a pen installed on a column of pump pipes, a poppet valve, a ball check valve, a filter, a hydrodynamic valve, a throttle coupling, a hydrostatic valve, which includes a plunger with bypass openings, a knock-off valve, characterized in that in the upper part of the device there is a valve with forced actuation, which opens when the device rests in the downhole plug and closes when the device is raised, except for On the other hand, the hydrostatic valve plunger is equipped with o-rings located above the bypass holes, and the bypass holes in it are made at an acute angle relative to the longitudinal axis of the device, towards the wellhead, while the hydrostatic valve cavity is provided with drain microvalves, and the hydrodynamic valve is located above filter, consists of a housing, an adjusting nut, a spring stop, a spring, a cone valve and a nozzle and initiates adjustable pressure pulses of liquid STI a wide frequency range, wherein the lower housing of the check valve is formed as a centralizer with the maximum permissible diametral dimensions for a particular well casing.

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