RU2322568C1 - Device for pipe expansion inside well - Google Patents

Abstract

FIELD: well drilling and overhaul, particularly cutting or destroying pipes, packers, plugs, or wire lines, located in boreholes or wells.

SUBSTANCE: device comprises body with central channel and depressions made in outer surface thereof and adapted to receive rollers with upper and lower axles. Annular piston is located in central body channel. The piston is spring-loaded from upper side in axial direction relatively the body. Rollers are fixedly connected with upper and lower axles and are installed in the body to provide roller rotation and limited radial displacement within gap. Inner annular recess is made in body over depressions. Cylindrical ledge of outer piston surface is installed in the annular recess. Inner body surface and outer surfaces of the piston and the cylindrical ledge define hydraulic chamber communicated with annular piston interior through radial orifices of the piston. Body may slide in axial direction relatively the piston. Lower part of annular piston is provided with outer conical surface, which may communicate with roller surfaces from within. Thread for device connection with downhole equipment is created at upper annular piston side.

EFFECT: decreased axial loads applied to body, simplified structure and decreased material inputs.

1 dwg

Description

The invention relates to drilling and overhaul of wells and is intended, in particular, for expanding expandable devices from expandable pipes when installing them in wells.

It is known "Device for flaring pipes" (patent RU No. 2191883, ЕВВ 29/10, publ. Bull. No. 30 dated 10.27.02), including a housing with a central channel, threads for connection with downhole equipment, and recesses on the outer surface in which the rollers are mounted on axles, the upper ends of which are fixed in the housing detachably, and the lower ones are mounted in supports placed in the housing by means of hinges with the possibility of turning them in a plane passing through the geometric axes of the housing and rollers.

The disadvantage of this analogue are:

- limited applicability, since the outer diameter of the circle, described around the rollers, which are not regulated by offset, cannot be larger than the diameter of the well;

- the possibility of emergency situations in the form of jamming during the descent and ascent of the device in horizontal wells and wells with a complex profile is not excluded, since the diameter of the circle described around the rollers is chosen as close as possible to the diameter of the well;

- high axial loads are necessary in the process of pipe expansion;

- high radial loads directly on the axis, significantly reducing their service life.

The closest in technical essence and the achieved result is a "Device for expanding pipes in the well" (patent RU No. 2235849, ЕВВ 29/10, publ. Bull. No. 25 dated 09.09.04), including a housing with a central channel, threads for connections with downhole equipment and recesses on the outer surface, in which the rollers are mounted on the axles, the upper ends of which are fixed in the housing detachably, and the lower ends are mounted in the supports, while the lower ends of the axes are mounted in the supports placed in the housing using hinges with opportunity In order to rotate them in a plane passing through the longitudinal geometric axes of the housing and the rollers, the upper ends of the rollers are installed in the housing with a radial clearance, and in the central channel of the housing there is a hydraulic ring piston axially spring loaded and having pushers interacting with the upper ends of the rollers.

The disadvantages of the device are:

- the complexity of manufacturing and, as a consequence, the high material costs of manufacturing;

- high axial loads are necessary in the process of pipe expansion;

- high radial loads directly on the axis, significantly reducing their service life.

An object of the invention is to reduce axial loads on the housing and radial loads on the axis of the rollers during operation, as well as simplifying the design of the device and, as a result, reducing material costs for manufacturing, repair and maintenance.

The technical problem is solved by a device for expanding pipes in a well, including a housing with a central channel and recesses on the outer surface, in which rollers with axles are placed, and an annular piston axially spring loaded in the central channel of the housing, as well as a thread for connecting to downhole equipment .

The new fact is that the rollers are rigidly connected to the axes, the upper and lower ends of which are mounted in the housing with the possibility of rotation and limited radial movement, while the housing is higher than the recesses into which the rollers are installed, equipped with an internal annular selection, in which a cylindrical step made on the outer surface of the annular piston, while the inner surface of the housing and the outer surfaces of the annular piston and its cylindrical stage form a hydraulic chamber in communication with the inner the space of the annular piston with radial holes made in the annular piston, the housing having the possibility of limited axial movement relative to the annular piston, while the lower part of the annular piston is provided with an external conical surface that can interact from the inside with the surface of the rollers, and the thread for connecting the device to the downhole equipment made at the upper end of the annular piston.

The drawing shows a device with a partial longitudinal section in the transport position.

A device for expanding pipes in a well comprises a housing 1 with a central channel 2 and recesses 3 on the outer surface 4, in which rollers 5 with upper 6 and lower 6 'axes are placed. In the central channel 2 of the housing 1 is placed an annular piston 7, spring loaded from above in the axial direction by means of a spring 8 relative to the housing 1.

The rollers 5 are rigidly connected to the upper 6 and lower 6 'axles, which are mounted in the housing 1 with the possibility of rotation and limited radial movement within the gaps 9 and 9', respectively. The housing 1 above the recesses 4, in which the rollers 5 are installed, is equipped with an inner annular selection 10, in which a cylindrical step 11 is installed, made on the outer surface of the annular piston 7.

The inner surface of the housing 1 and the outer surfaces of the annular piston 7 and its cylindrical stage 11 form a hydraulic chamber 12. The hydraulic chamber 12 communicates with the inner space 13 of the annular piston 7 by radial holes 14 made in the annular piston 7. The housing 1 has the possibility of axial movement relative to the annular piston 7. The lower part of the annular piston 8 is provided with an outer conical surface 15, which is able to interact from the inside with the surface of the rollers 5. The spring 8 is fixed against eniya during operation by means of a stopper 16 fixed to the upper end of the annular piston 7.

At the upper end of the annular piston 7, a thread 17 is made for connecting the device to downhole equipment (not shown).

In order to exclude unauthorized fluid flows during operation of the device, the mating surfaces are provided with sealing elements 18 and 19.

A device for expanding pipes in the well works as follows.

Expandable pipes are lowered into a well (not shown) in the installation interval (not shown), in which they create excess pressure, previously pressing them to the walls or to the casing (not shown) of the well. Next, the complete assembly using the thread 17 (see the figure) is connected to the downhole equipment and the pipe string (not shown).

Next, the device on the pipe string is lowered into the well to the interval for installing the expandable pipe, while the pipe string is filled with borehole fluid through the inner space 13 of the annular piston 7. When the device reaches the upper end of the expandable pipe, the pipe string (not shown) begins to rotate while creating an axial load and washing the cavity of the pipe string and the inner space 13 (see the figure) of the annular piston 7 by pumping liquid.

In the process of pumping fluid, the latter through the radial holes 14 of the annular piston 7 enters the hydraulic chamber 12. The flow of fluid into the pipe string and accordingly into the inner space 13 of the annular piston 7 is increased. As a result, the fluid pressure in the hydraulic chamber 12 rises and the housing 1 with the rollers 5 located in it moves upward relative to the stationary stationary piston 7, while the spring 8 is compressed, and the annular piston 7 is shifted downward by its cylindrical step 11 within the inner ring selection 10 of the housing one.

At this moment, the annular piston 7 with its outer conical surface 15, acting on the rollers 5, shifts the latter radially outward within the clearances 9 and 9 'relative to the housing 1. As a result, the rollers 5 occupy a working position. The rotation of the pipe string continues, while the rollers 5, rotating in the recesses 4 of the housing 1, interact with the expandable pipe, which is tightly and tightly pressed against the wall of the well or to the casing along the entire length. The rollers 5 interact with the conical surface 15 of the annular piston 7, rotating around their upper 6 and lower 6 'axles due to the rotation of the annular piston 7, and the housing 1 remains stationary.

At the end of the flaring, the washing of the liquid is stopped, and accordingly, the pressure of the liquid in the inner space 13 of the annular piston 7 and the hydraulic chamber 12 decreases sharply, while the housing 1 and the rollers 5 located therein are returned to the transport position due to the return force of the spring 8, while the rollers 5 move downward relative to the conical surface 15 of the annular piston 7, and also move radially inward, occupying a transport position.

Due to the fact that the rollers 5 during the rolling process of the expandable pipe interact with the conical surface 15 of the annular piston 7, while rotating in different directions, while the housing 1 remains stationary, which reduces axial loads on the housing and radial loads on the axis of the rollers during operation. In addition, the device has a simple design, which allows to reduce material costs for manufacturing, repair and maintenance.

Claims (1)

A device for expanding pipes in a well, including a housing with a central channel and recesses on the outer surface, in which rollers with axles are placed, and an annular piston, axially spring-loaded, as well as a thread for connecting to downhole equipment, are located in the central channel of the housing, characterized in that the rollers are rigidly connected to the axes, the upper and lower ends of which are mounted in the housing with the possibility of rotation and limited radial movement, while the housing is higher than the recesses in which of the rollers, is equipped with an internal annular selection into which a cylindrical stage is installed, made on the outer surface of the annular piston, while the inner surface of the housing and the outer surfaces of the annular piston and its cylindrical stage form a hydraulic chamber in communication with the inner space of the annular piston by radial holes made in an annular piston, the housing having the possibility of limited axial movement relative to the annular piston, the lower part of the rings of the piston is provided with an external conical surface that can interact with the surface of the rollers, while the thread for connecting the device to the downhole equipment is made at the upper end of the annular piston.