RU55019U1 - DEVICE FOR CLEANING A WELL FROM A SAND STOCK - Google Patents

Abstract

The proposal relates to the oil and gas industry and can be used for maintenance and overhaul to clean wells of sand plugs. A device for cleaning a well from sand plugs consists of a housing, at the upper end of which there is a cable termination. A check valve with an adjustable spring is placed in the cable termination. Radial channels are made at the lower end of the housing. The bottom of the case is plugged and equipped with a tip. On the tip with the possibility of axial movement placed a hollow sleeve, spring-loaded from the bottom of the tip to the lower end of the housing by means of a spring. The outer diameter d _{1 of the} hollow sleeve is larger than the outer diameter d _{2 of the} casing, but smaller than the inner diameter d _{3 of the} shoe. The shoe is made in the form of a hollow cylinder and is located on the outer surface of the housing. The shoe is pushed from above relative to the housing by means of a spring. In the initial position, the radial channels are blocked by a shoe. The shoe with its outer surface has the ability to tightly interact with the inner surface of the inner protrusion of the wellhead. Bottom of the shoe is supported by a hollow sleeve, while they have the possibility of joint axial movement down, due to interaction with the wellhead. The shoe has the ability to axially move below the radial channels of the housing when emptying the device. The proposed device has a simple design that eliminates the unauthorized operation of the shoe, which allows with sufficient high efficiency to clean the well from sand plugs, and thus reduce the duration and cost of repair work.

Description

The proposal relates to the oil and gas industry and can be used for maintenance and overhaul to clean wells of sand plugs.

A device for cleaning the bottom of the well from sand plugs (copyright certificate SU No. 901476 IPC 7 E 21 V 37/00 publ. Bull. No. 4 dated 01/30/1982), consisting of a housing with a receiving valve, a piston rod, the piston is sealed with a cuff relative to the body, wellhead outlet, while the receiving valve is located in the piston, and a float valve with a spring-loaded seat is installed above the piston, and the body is made with channels above the spring-loaded seat at the level of the wellhead.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts. In addition, the wellhead is technologically difficult to manufacture and use.

- secondly, the cuff wears out quickly in an aggressive environment (abrasive, sand, sludge), with which it directly contacts in the process of cleaning the bottom of the well, in connection with which the efficiency of the device decreases sharply.

The closest in technical essence to the proposed is a device for cleaning wells from sand plugs (copyright certificate SU No. 1186787 IPC 7 E 21 V 37/00 publ. Bull. No. 39 dated 23.10.1985), including wellhead with internal protrusion, a casing with a check valve and radial channels for alignment with the channel of the wellhead outlet and axially movable shoe, the casing having radial channels and the shoe made in the form of rigidly interconnected lower part of the bushes concentrically mounted relative to one another and the body forming the annular cavity and the spring-loaded nozzle installed in the annular cavity with the outer annular protrusion for interacting with the upper ends of the bushes and the protrusion for interacting with the upper ends of the bushes and the protrusion of the wellhead, while the bushes are installed with the possibility of overlapping an additional radial channel of the housing, and the pipe - with the possibility of overlapping the radial channel of the housing.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts, and as a consequence, the complexity of manufacturing and assembly;

- secondly, when the device is lowered into the well, premature additional radial channels of the housing can be opened prematurely if atmospheric pressure remains in the annular cavity where the spring is installed, and vice versa, when lifting, if there is liquid below the bushings, then a “piston effect” will be created ", Counteracting the spring unloading, while additional radial channels may not overlap with the bushings, in addition, the spring during operation is subjected to significant alternating loads, the excess of which Above the allowable values, it can lead to spring breakage; in connection with the foregoing, the reliability of the device for cleaning the well from sand plugs decreases.

- thirdly, the shoe in the process of cleaning the well of sand plugs can become clogged with large pieces of deposits, which can complicate or block the access of the cleaned sand plug to the device body, and therefore, the efficiency of well cleaning is reduced

The objective of the utility model is to simplify the design of the device and increase the reliability and efficiency of the device.

The problem is solved by the proposed device for cleaning the well of sand plugs, including wellhead with an internal protrusion, a housing with a check valve and radial channels, axially movable shoe, sealing elements, sealing elements.

New is that the shoe is made in the form of a hollow cylinder and is spring-loaded from above relative to the housing with the possibility of tight closure of the radial channels of the housing, while the housing is provided with a tip on the bottom, on which a hollow sleeve is placed, spring-loaded from the bottom from the tip to the lower end of the housing, the outer diameter d ₁ the hollow sleeve greater than the outer diameter d _{2 of} the housing, but smaller than the inside diameter d ₃ of the shoe, the shoe bottom is backed by a hollow sleeve and the outer surface of the shoe has the ability to hermetically taken from interaction with the inner surface of the inner wellhead protrusion removal, and also has an axially displaceable down below the radial passages housing after interacting with the inner wellhead tap protrusion.

The figure shows a device for cleaning wells from sand plugs in longitudinal section.

A device for cleaning a well from sand plugs consists of a housing 1, at the upper end of which there is a cable termination 2. In the cable termination 2 there is a check valve 3 with an adjustable spring 4. At the lower end of the housing 1 there are radial channels 5. The bottom of the housing 1 is plugged and provided tip 6.

On the tip 6 with the possibility of axial movement is placed a hollow sleeve 7, spring-loaded from the bottom of the tip 6 to the lower end of the housing 1 by means of a spring 8.

The outer diameter d _{1 of the} hollow sleeve 7 is larger than the outer diameter d _{2 of the} housing 1, but smaller than the inner diameter d _{3 of the} shoe 9.

The shoe 9 is made in the form of a hollow cylinder and is located on the outer surface of the housing 1. From the bottom, the shoe 9 is supported by the hollow sleeve 7. The shoe 9 is pressed from above relative to the housing 1 by means of the spring 10. In the initial position, the radial channels 5 are closed by the shoe 9.

The shoe 9 with its outer surface has the ability to tightly interact with the inner surface of the inner protrusion 11 of the wellhead 12, and the shoe 9 and the hollow sleeve 7 have the possibility of joint axial movement down.

The mating surfaces of the housing 1 and shoe 9 are equipped with o-rings 13. Unauthorized fluid flows from the housing 1 when the device is emptied are prevented by the sealing elements 14 and 15, which are installed on the outer surfaces of the housing 1 and shoe 9, respectively.

A device for cleaning wells from sand plugs is as follows.

Wellhead 12 is passed upward through the cable termination 2 connected to the cable 16. After that, the cable termination 2 is screwed onto the upper end of the housing 1. The device is lowered into the well 17 and the wellhead 12 is secured to the wellhead 17. Then the device is placed on the rope of the cable 16 by means of geophysical the hoist (not shown in Fig.) is lowered into the well 17. When the device is lowered below the fluid level in the well, the cavity of the housing 1 remains hermetically closed and inaccessible to liquid penetration, due to the sealing rings 13.

When the shoe 9, made in the form of a hollow cylinder with a sand plug 18 in the well 17, comes into contact, the housing 1 falls down under the action of its own weight, compressing the spring 10 fixed from above relative to the housing 1, while the radial channels 5 open. Under the influence of the hydrostatic pressure of the liquid column in well 17 and due to the fact that the outer diameter d _{1 of the} hollow sleeve 7

more than the outer diameter d _{2 of the} casing 1, but smaller than the inner diameter d _{3 of the} shoe 9, sand is intensively sucked into the inner cavity 19 of the casing 1 above the tip 6. When the pressure in the inner cavity 19 of the casing 1 and in the inner space of the well 17 is equalized, the flow of sand will stop.

After that, the device through the rope 16 begin to lift up. At the moment of lifting the device, the shoe 9 under the influence of its own weight and the return force of the spring 10 drops down and blocks the radial channels 5, separating the internal cavity of the housing 1 from the internal space of the well 17. During the lifting of the device, compressed air formed when the internal cavity of the housing 1 is filled with sandy mixture leaves through the check valve 3 until it reaches the pressure to which the check valve 3 is adjusted by the spring 4. From practical experience this is 0.1-0.3 MPa. Pressure is intended for intensive emptying of the device.

When the device reaches the wellhead 17, the shoe 9 with its outer surface hermetically interacts with the inner surface of the inner protrusion 11 of the wellhead 12.

They continue to pull the rope 16 upward, while the shoe 9 rests on top of the inner protrusion 11 of the wellhead 12 and, with the rope 16 further pulled upward, the shoe 9 lowers, shifting the hollow sleeve 7 downward, compressing the spring 8 which is supported from below into the tip 6, while the shoe 9 It turns out below the radial channels 5, which are opened by excessive air pressure in the internal cavity 19 of the housing 1, sand is forcibly ejected through the channels 20 of the wellhead 12.

Upon completion of the cleaning of the internal cavity 19 of the housing 1 from sand, the device is lowered into the well 17, while under the action of the return force of the spring 8, the hollow sleeve 7 rises up to the stop in the lower end of the housing, dragging the shoe 9 from above, which overlaps the radial channels 5 of the housing 1.

Next, the device is dismantled or re-lowered into the well for its subsequent cleaning from the sand plug.

The proposed device has a simple design that eliminates the unauthorized operation of the shoe, which allows with sufficient high efficiency to clean the well from sand plugs, and thus reduce the duration and cost of repair work.

Claims (1)

A device for cleaning a well from a sand plug, including a wellhead outlet with an internal protrusion, a body with a check valve and radial channels, an axially movable shoe, sealing elements, characterized in that the shoe is made in the form of a hollow cylinder and is spring-loaded relative to the body with a sealed overlap of the radial channels of the housing, while the housing is provided with a tip at the bottom, on which a hollow sleeve is placed, spring-loaded from the bottom from the tip to the lower end of the housing, the diameter d _{1 of the} hollow sleeve is larger than the outer diameter d _{2 of the} casing, but smaller than the inner diameter d _{3 of the} shoe, while the shoe is supported from below by the hollow sleeve, and the outer surface of the shoe has the ability to tightly interact with the inner surface of the inner protrusion of the wellhead, and also has the possibility of axial moving down below the radial channels of the housing after interacting with the inner protrusion of the wellhead outlet.