RU2455462C1 - Device for well cleaning from sand pack - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: device includes cross-over module, hollow housing tightly connected to the outer impact bit at the bottom part, operating chamber located in the hollow housing and damage mechanism coaxially mounted in the hollow housing. The outer bit is equipped with end teeth and has inclined radial holes directed upwards. The hollow housing is spring-loaded in relation to cross-over module. Damage mechanism includes hollow connecting rod, internal impact bit and valve installed with the possibility of restricted axial movement. The internal bit is fixed at hollow connecting rod, equipped with end teeth and has inclined radial channels directed downwards. The hollow unloading rod is tightly connected to the cross-over module and has two rows of through longitudinal slots. Operating chamber consists of three inserts welded in elastic elements with common axial channel. The upper insert has end threaded hole with oil cup installed in it and inclined channel directed towards the hollow housing. The inner surface of the lower insert in the middle part is made in a form of a saddle for damage mechanism valve. The holes of outer bit have length that provides their combination with the channels of internal bit in the end lower position of damage mechanism. The valve is installed in the cavity of unloading rod and has two rows of through longitudinal slots.

EFFECT: increase of device operation efficiency, reliability.

5 dwg

Description

The invention relates to the operation and repair of wells and can be used to clean the well from sand plugs.

Analysis of the current level of technology showed the following.

A device is known for cleaning a well from sand plugs (see No. 2242585 dated 05/28/2003, class E21B 37/00, E21B 21/00, publ. 12/20/2004), containing a transition module, a hollow body rigidly connected in the lower part to an external impact crown (casing) equipped with end teeth, a working (expansion) chamber, a fracture mechanism, coaxially mounted in a hollow body, including a hollow rod, an internal impact crown equipped with end teeth and having radial channels fixed on a hollow stock, and a valve. The fracture mechanism is spring loaded relative to the hollow body. The inner impact crown has an axial throttle bore. The hollow body has circulation openings.

The disadvantage of this device is the following:

low efficiency of destruction of the sand cork due to the weak impact caused by impact crowns. The accumulation of pressure to move the fracture mechanism occurs in the pipe string due to the resistance that occurs when the working agent passes through the radial channels of the impact crown and the axial throttle hole. Structurally, these channels and the hole are always open, therefore, only part of the working agent is involved in the energy storage, which cannot create a lot of pressure;

low quality of cleaning from the products of destruction due to the fact that the increase in the velocity of the upward flow occurs when opening the circulation holes in the housing located outside the zone of destruction. In addition, when the working agent passes through the pipe string and inside the device, additional pressure losses occur that reduce the hydro-monitor effect, which affects both the destruction efficiency and the quality of cleaning;

low reliability associated with the difficulty of returning the fracture mechanism to its original position due to the impossibility of a complete release of pressure in the axial channel of the device and insufficient elastic spring force to overcome the specified pressure.

As a prototype, a device was selected for cleaning a well from sand plugs (see No. 2315174 dated May 22, 2006, according to class E21B 37/00, published January 20, 2008) containing a transition module, a hollow body, rigidly connected at the bottom with an external impact crown equipped with end teeth and having inclined upwardly directed radial holes, spring-loaded relative to the adapter module through an adapter, a working chamber located in the hollow housing, and a fracture mechanism coaxially mounted in the hollow housing, including the hollow connecting th rod, an inner impact crown equipped with end teeth and having inclined downward radial channels fixed to the hollow connecting rod, and a valve mounted with the possibility of limited axial movement by means of a spring. The working chamber is formed by a sub, the inner channel of which has a conical extension to the bottom. The device contains a hydrodistribution unit, providing interconnection with the annular space and the rotational effect on the sand cork. A cavity is formed between the inner impact crown and the housing, hydraulically connected to the inclined upward radial openings of the outer impact crown.

The disadvantages of the device are the following:

low efficiency of destruction of the sand plug due to the weak impact caused by the internal and external impact crowns, and the low hydro-monitor effect of the working agent jet associated with the loss of pressure of the working agent when the latter moves along the pipe string and inside the device. The working chamber is structurally designed so that it does not allow energy storage to increase the impact power. The device creates additional losses of hydraulic pressure due to the low mechanical efficiency of the device due to the movement of the rubbing structural elements. Moreover, only a part of the working agent enters the working chamber formed by the sub, since the axial hydraulic channel is open, through which through the inclined downward radial channels another part in the form of a jet acts on the sand cork;

low quality of cleaning from the products of destruction due to the fact that the removal is carried out by a jet, which has low kinetic energy and the speed of the release of the working agent due to hydraulic losses. The external impact crown has inclined upward radial holes, however, they are designed to reduce hydraulic losses during the movement of the internal impact crown up to displace the working agent from the cavity located between the internal impact crown and the body, and do not take part in improving the quality of the removal of fracture particles;

low reliability, due to the complex kinematic scheme of the device design, involving both axial movement of parts and their rotation.

The technical result that can be obtained by carrying out the invention is to increase the efficiency of destruction of the sand cork and the quality of cleaning from the products of destruction due to the constructive implementation of the working chamber, which allows the accumulation of energy of the working agent, providing high impact force and the creation of a powerful jet monitor. In addition, the reliability of the device increases due to the simplification of the kinematic scheme, with the constructive design of the working chamber and the supply of lubricant between the wall of the housing and the elastic elements of the working chamber to reduce the friction forces arising between them.

The technical result is achieved using a known device for cleaning a well of a sand plug containing a transition module, a hollow body rigidly connected in the lower part to an external impact crown equipped with end teeth and having inclined radial holes directed upward, spring-loaded relative to the transition module through an adapter, a working chamber located in the hollow body, and a destruction mechanism coaxially mounted in the hollow body, including the hollow connecting rod, internal shock a crown equipped with end teeth and having inclined downwardly directed radial channels mounted on a hollow connecting rod, and a valve mounted with the possibility of limited axial movement.

The inventive design further comprises a hollow discharge rod coaxially mounted in the hollow body, rigidly connected to the transition module and having two rows of through longitudinal grooves.

The adapter module according to the claimed design consists of a hollow rod with a restrictive nut.

The hollow body has a collar on the inner surface.

The sub is made in the form of a union nut.

The working chamber consists of three embedded parts with a common axial channel welded into elastic elements. The upper embedded part is pressed to the shoulder of the hollow body with a union nut through the spacer sleeve and has an end threaded hole with a grease fitting installed in it and an inclined channel directed to the hollow body. The middle embedded part has radial threaded holes. The lower embedded part is made with a protrusion in the lower part, connected by a threaded connection to the hollow connecting rod of the fracture mechanism. In this case, the inner surface of the lower embedded part in the middle part is made in the form of a saddle under the valve of the fracture mechanism.

The internal impact crown of the fracture mechanism has inclined upward radial channels. The inclined upward radial holes of the external impact crown are made in length, ensuring their alignment with the inclined upward radial channels of the internal impact crown when the fracture mechanism is in its lowest position.

The valve of the fracture mechanism is installed in the cavity of the unloading rod and has two rows of through longitudinal grooves.

Pins are installed in the radial threaded holes of the middle embedded part of the working chamber, the free ends of which through the upper row of through longitudinal grooves of the hollow discharge rod are placed in the upper row of through longitudinal grooves of the valve.

We have not identified sources containing information on technical solutions, including the entire set of features of the invention, which allows us to conclude that it meets the condition of novelty.

Figure 1 shows the design of the device in longitudinal section.

Figure 2 presents the cross section of the device along the line aa in figure 1.

Figure 3 presents a cross section of the device along the line BB in figure 1.

Figure 4 presents a cross section of the device along the line BB in figure 1.

Figure 5 presents a graph of the relative elongation from stress in the cross section of the elastic element.

The inventive device for cleaning a well from a sand plug contains a transition module consisting of a hollow rod 1 and a restrictive nut 2, a hollow body 3. The hollow body 3 is rigidly connected in the lower part to the external impact crown 4 and is spring loaded relative to the transition module through an adapter (Fig. 1 ) The sub is made in the form of a union nut 5. The hollow body 3 has a collar 6 on its inner surface. The external impact crown 4 is equipped with end teeth 7 and has inclined radial holes 8 directed upward.

The device comprises a working chamber located in the hollow body 3. The working chamber consists of three embedded parts - the upper embedded part 9, the middle embedded part 10 and the lower embedded part 11 with a common axial channel welded into the elastic elements 12 (figure 2). The upper embedded part 9 is pressed against the shoulder 6 of the hollow body 3 with a union nut 5 through the spacer sleeve 13 and has an end threaded hole with a grease fitting 15 installed in it and an inclined channel 16 directed towards the hollow body. The middle embedded part 10 has four radial threaded holes 17 (figure 3).

The device comprises a fracture mechanism coaxially mounted in the hollow body 3. The fracture mechanism includes a hollow connecting rod 18, an internal impact crown 19 mounted on it, and a valve 20. The valve 20 is mounted with limited axial movement. The inner impact crown 19 is provided with end teeth 21 and has inclined radial channels 22, 23 directed down and up (Fig. 4). The inclined upward radial holes 8 of the outer impact crown 4 are made in length, ensuring their alignment with the inclined upward radial channels 23 of the inner impact crown 19 when the fracture mechanism is in its lowest position.

The device comprises a hollow discharge rod 24, coaxially mounted in the hollow body 3, rigidly connected with the transition module. The hollow unloading rod 24 has two rows of through longitudinal grooves 25.

The lower embedded part 11 of the working chamber is made with a protrusion 26 in the lower part, connected by a threaded connection to the hollow connecting rod 18 of the fracture mechanism. The inner surface of the lower embedded part 11 in the middle part is made in the form of a seat 27 under the valve 20 of the destruction mechanism. The valve 20 of the destruction mechanism is installed in the cavity of the unloading rod 24 and has two rows of through longitudinal grooves 28. In the radial threaded holes 17 of the middle embedded part 10 of the working chamber, pins 29 are installed, the free ends of which through the upper row of through longitudinal grooves 25 of the hollow unloading rod 24 are placed in the upper row of through longitudinal grooves 28 of the valve 20.

The number of through longitudinal grooves 25, 28 of the hollow discharge rod 24 and the valve 20 of the destruction mechanism, the number of threaded holes 17 in the middle embedded part 10 of the working chamber and, accordingly, the number of pins 29 are performed based on the structural dimensions and axial tensile forces.

And the number of inclined, directed up and down radial channels 23, 22 of the inner impact crown 19, is calculated depending on the size of the device.

The device operates as follows.

The device is lowered into the well on a string of flexible pipes until the external impact crown 4 contacts the sand plug. Submit a working agent, which can be used highly aerated solutions, foam systems or gas. The valve 20 of the destruction mechanism is located in the seat 27 of the lower embedded part 11 of the working chamber, thereby blocking the passage section of the seat. The working agent through the channel of the hollow rod 1 and the hollow discharge rod 24 through the through longitudinal grooves 25 in the hollow discharge rod 24 and the through longitudinal grooves 28 in the valve 20 transfers pressure to the elastic elements 12 of the working chamber. The elastic elements 12 are deformed in the radial direction and stretched in the axial direction, while providing an increase in pressure in the working chamber in proportion to the relative stretching of the elastic elements 12. The need to increase the pressure in the device is justified by large losses of working pressure in the string of flexible pipes, which reduces the hydrodynamic effect erosion of the sand cork and a decrease in the power of impacts on the cork, and the low costs of the working agent do not allow creating the necessary removal rate for destruction of products well.

The accumulation of kinetic energy occurs due to the elastic forces of the elastic elements 12. The tensile force in the elastic element 12 is determined by the product of its cross-sectional area by the stress arising in the specified section. In turn, the stress in the cross section of the elastic element 12 will depend on its relative elongation in direct relation to the maximum allowable stress. The dependence is reflected graphically (figure 5), taking the relative elongation as the calculated value, determine the magnitude of the generated voltage in the cross section. The pressure generated in the working chamber during operation will be determined by the size of the working cross-sectional area of the elastic element 12.

The lower embedded part 11 of the working chamber and the elastic element 12 connecting it to the middle embedded part 10 move with great speed down, resulting in a translational shock movement through the hollow connecting rod 18 of the inner impact crown 19. In the working chamber, the valve 20 of the fracture mechanism moves down simultaneously in the saddle 27 of the lower embedded part 11 relative to the hollow discharge rod 24 and when choosing a free play (the moment of landing of the upper ends of the through longitudinal grooves 28 of the valve 20 on the pins 29 installed in the threads the holes of the middle embedded part 10) stops. The lower embedded part 11 continues to move downward, which leads to the opening of the axial channel of the saddle, providing a water hammer by the jets of the working agent through the inclined downward radial channels of the internal impact crown 19, and the combination of the inclined upward radial channels 23 of the internal impact crown 19 with the radial holes 8 of the external shock crowns 4. A working agent with high pressure and high speed along the axial channel of the hollow connecting rod 18 is ejected through the inclined upward rad the channels 23 of the inner impact crown 19 and the inclined upward radial holes 8 of the outer impact crown 4. The working agent is pulsed in the direction of the removal of particles of fracture products, a fan-shaped hydraulic packer is created that facilitates high-quality capture and removal of fracture products of the sand plug from the well .

There is a pressure relief in the working chamber and the inner impact crown 19, the hollow connecting rod 18 and the lower embedded part 11 of the working chamber by the internal elastic forces of the elastic element 12 of the working chamber are returned to their original position. The elastic forces of the elastic element 12 exceed the value of the forces created by the pressure of the working agent, which ensures the reliability of the device. An oiler 15 installed in the end threaded hole 14 of the upper embedded part 9 ensures that the lubricant material fills the space between the housing wall and the elastic elements 12 along the inclined channel 16. The lubricant reduces the friction forces arising between them, ensuring the reliability of the device. The filling of the specified space with lubricant is carried out at the time of installation of the device. The rubber sealing rings installed in the upper 9 and lower 11 embedded parts prevent the displacement of the lubricant.

The valve 20 of the destruction mechanism sits in the seat 27 of the lower embedded part 11, blocking the axial channel of the seat 27.

At the time of energy storage in the working chamber, the middle embedded part 10 maintains its original position, which is achieved by the presence of radial threaded holes 17 in it and due to the location and constructive execution of the hollow unloading rod 24, which provide support for the pins 29 installed in these radial threaded holes 17, on lower ends of the through longitudinal grooves 25 of the upper row of the hollow discharge rod 24.

Simultaneously with the movement of the lower embedded part 4, the upper embedded part 9 is axially moved upward, which, through the expansion sleeve 13, transmits the movement to the union nut 5, the hollow body 3 and the external impact crown 4. The latter, overcoming the spring force, occupy the highest position, and when reset the pressure in the working chamber is lowered at high speed, impacting the external impact crown 4 on the sand cork.

When the valve 20 closes the mechanism of destruction of the axial channel of the saddle 27 of the lower embedded part 11, the entire working process is repeated.

Thus, the design of the working chamber and its relationship with other elements of the device allow for one powerful cycle of lifting and depressurizing it to deliver two powerful blows to the sand plug, since when the inner impact crown 19 moves down, the outer impact crown 4 rises up, the movement of the inner impact crown 19 upward, the outer impact crown 4 moves down. There is an effective destruction of the sand cork, determined by the impact force, as well as the power of the jet, which produces both destruction and high-quality cleaning.

A device for cleaning a well from sand plugs is an integral part of a complex of equipment that ensures the repair of wells for various purposes using a string of flexible pipes. When working with a string of flexible pipes with a nominal diameter of 38 mm, a device weighing 14.8 kg is used, having the following dimensions:

length mm 680 outer diameter mm 76.

In the hollow discharge bar 24, 2 rows of through longitudinal grooves of 4 in each are made. The number of threaded holes in the middle embedded part 10 of the working chamber and, accordingly, the number of pins 29, as well as the number of through longitudinal grooves 28 of the valve 20 of the fracture mechanism in each row, is 4. The internal impact crown 19 has 8 inclined radial channels upward 23 and downward 22. The outer impact crown 4 has 8 inclined, upwardly directed radial holes 8, made 56 mm long.

All places requiring tightness are sealed with rubber rings made in accordance with GOST 9833-73.

The elastic elements 12 of the working chamber are made of rubber grade 7-57-2012 of group VI-1b-10 according to TU 2512-046-00152081-2003. From the elasticity characteristics of the elastic element 12, the relative elongation is dependent on the stress in the cross section of the elastic element 12 to the maximum permissible value. According to the schedule (figure 5), the actual relative elongation is 450%, the ultimate stress is 210 kg / cm ² . With a relative elongation of 300%, the stress in the cross section is 140 kg / cm ² . The tensile force in the elastic element 12 is determined by the formula

F _p = σ _p · S _el ,

where F _p - tensile force, kg,

σ _p - stress in the cross section of the elastic element, kg / cm ² ,

S _el - the cross-sectional area of the elastic element, cm ² .

F _p = 14013.4 = 1876 kg.

In the working chamber during operation, pressure is created, determined by the formula

P _in = F _p / S _p ,

where P _in - pressure in the working chamber during operation, kg,

S _p is the working area, which is formed in the working chamber during operation, cm ² ,

P _in = 1876 / 23.4 = 80 kg / cm ² .

This pressure provides the creation of a powerful jet monitor and impacts of the inner 19 and outer 4 shock crowns, effectively destroying the sand plug, as well as the implementation of high-quality cleaning of the destruction products.

We have not found sources of patent documentation and scientific and technical literature describing information about the influence of the distinctive features of the device on the achieved technical result. The technical solution does not explicitly follow from the prior art, i.e. meets the condition of "inventive step".

The claimed technical solution meets the condition of patentability, as it is new, has an inventive step and is industrially applicable.

Claims (1)

A device for cleaning a well from a sand plug containing a transition module, a hollow body rigidly connected in the lower part to an external impact crown equipped with end teeth and having inclined upward radial holes spring-loaded relative to the transition module through an adapter, a working chamber located in the floor case, and the destruction mechanism, coaxially mounted in the hollow body, including a hollow connecting rod, an internal impact crown, equipped with end teeth and having a slope downward radial channels mounted on a hollow connecting rod and a valve mounted with limited axial movement, characterized in that it further comprises a hollow discharge rod coaxially mounted in the hollow body, rigidly connected to the transition module and having two rows of through longitudinal grooves, and the adapter module consists of a hollow rod with a restrictive nut, and the hollow body has a collar on the inner surface, and the sub is made in the form of a union nut, while The chamber consists of three embedded parts with a common axial channel welded into elastic elements, while the upper embedded part is pressed against the shoulder of the hollow body with a union nut through the spacer sleeve and has an end threaded hole with a grease fitting installed in it and an inclined channel directed towards the hollow body , the middle embedded part has radial threaded holes, and the lower embedded part is made with a protrusion in the lower part, connected by a threaded connection to the hollow connecting rod of the fracture mechanism, when the inner surface of the lower embedded part in the middle part is made in the form of a saddle under the valve of the fracture mechanism, and the inner impact crown of the fracture mechanism has inclined upward radial channels, and inclined upward radial holes of the external impact crown are made in length, ensuring their combination with inclined directed upward by the radial channels of the inner impact crown when the fracture mechanism is in its lowest position, while the valve of the fracture mechanism pins are installed in the cavity of the discharge rod and has two rows of through longitudinal grooves, and pins are installed in the radial threaded holes of the middle embedded part of the working chamber, the free ends of which through the upper row of through longitudinal grooves of the hollow discharge rod are placed in the upper row of the through longitudinal grooves of the valve.

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