RU2465433C1 - Device for screwing-off and destruction of reamed string - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: proposed device comprises casing with flushing channel and mandrel arranged thereon and furnished with chip removal flutes, and cutting elements arranged radially and regularly relative to rotational axis under said casing. Said casing has circular bulge chamfered on mandrel side and lengthwise recesses. Every said flat is made up of interconnected radial and tangential surfaces. Note here that radial surface faces the side of rotation. Note also that mandrel is aligned with the casing and rigidly coupled therewith to cover flushing channel. Mandrel central bore communicates with flushing channel. Mandrel chip removal flutes represent face channel expanding toward periphery, arranged nearby cutting elements in direction of rotation and communicated via operational opening with flushing channel. Said flutes are arranged closer to mandrel rotational center and communicated with lengthwise recesses via grooves on mandrel cylindrical surface. Casing chamfered bulge is made from material harder than shoe material and softer than that of reamed string. Note here that diameter of said bulge and chamfer angle are selected to allow fitting the mandrel inside string when device slides over well wall.

EFFECT: higher efficiency and reliability.

1 dwg

Description

The invention relates to the oil and gas industry and is intended for lapel and destruction of the shoe when installing expandable columns from profile and cylindrical pipes in wells.

Known milling cutter (RU patent for utility model No. 34620, IPC 7 E21B 29/00, published in Bull. No. 34 of 12/10/2003), including a cylindrical body with flushing holes, the upper end of which has a thread for connection to a drill string pipes, a cutting tool with cutting elements, moreover, the cutting elements are made with wear-resistant inserts providing stepwise cutting of the window, the milling cutter additionally contains auxiliary equipment, thrust and centering inserts, and auxiliary equipment is made with the main cutting elements Whether guide, moreover, the cutting elements are removable, easy regrinding on conventional equipment.

The disadvantages of this device are:

- the impossibility of the milling machine inside the expandable columns of profile and cylindrical pipes, since the cutting elements on the periphery of the device are made without taking into account the protection of the pipe walls in transition sections with different diameters;

- the possibility of an emergency when the device enters the expandable string in horizontal sections of the wells, since the cutting elements located on the periphery of the device can damage the end of the expandable string.

The closest in technical essence and the achieved result is a device for pipe expansion and shoe destruction in the well (RU patent for utility model No. 81518, IPC E21B 29/10, published in Bul. No. 8 of 03.20.2009), containing a housing and a mandrel mounted on it on an inclined axle with the possibility of rotation, the outer surface of which is formed by alternating sections of the surface of the ball and curved surfaces mating with each other, with curved surfaces formed by the lateral surfaces of the cylinders, the axes of which are located in a plane perpendicular to the axis of rotation of the mandrel of the plane, and the bottom mandrel is equipped with cutting elements placed on the surface evenly relative to the axis of rotation of the mandrel with the possibility of interaction and destruction of the shoe, while the cutting edge of the cutting elements is more remote from the center of the surface of the mandrel ball than forming the surface of the ball surface itself in addition, the cutting elements can be placed radially on the continuation of the ribs formed by alternating sections of the surface of the ball and curly surfaces, and equipped with flutes for chip removal.

The disadvantages of this device are:

- high axial loads during destruction of the shoe, associated with the simultaneous expansion of the expandable column pipes;

- a high likelihood of jamming of the device and breakage of the cutting elements due to the lack of washing in the cutting zone and insufficient cross-section of the channels to remove chips.

The technical task of the invention is to increase the reliability and operability of the device for the lapel and destruction of the shoe of expandable columns, especially in deviated and horizontal sections of wells due to reliable centering of the device at the inlet and inside of the expandable column, eliminating damage to the walls of the column by cutting elements, as well as reducing axial and radial loads during destruction of the shoe.

The technical problem is solved by a device for the lapel and destruction of the shoe expandable columns, containing a housing with a flushing channel, a mandrel mounted on it, equipped with channels for removing chips and bottom cutting elements placed radially and evenly relative to the axis of rotation.

New is that the housing is equipped with an annular extension with a chamfer on the mandrel side and longitudinal samples, each of which is made in the form of connected radial and tangential planes, the radial facing in the direction of rotation, and the mandrel coaxially and rigidly connected to the housing, blocking the flushing channel, and provided with a Central hole in communication with the flushing channel, while the channels of the mandrel for removing chips are made in the form of radial, expanding to the periphery of the end channels located at the cutting elements along the rotation and technological holes communicated with the washing channel located closer to the center of rotation of the mandrel, and with longitudinal selections of grooves on the cylindrical surface of the mandrel, the expansion with the bevel of the body made of material harder than the material of the shoe, and less solid than the material expandable columns, while the diameter of this expansion and the angle of the chamfer are selected with the possibility of introducing the mandrel inside the expandable column when sliding the device along the wall of the well.

The drawing shows a device for lapel and destruction of the shoe expandable columns (partially in section).

The device comprises a housing 1 with a flushing channel 2, a mandrel 3 mounted thereon with channels 4 for removing chips and bottom cutting elements 5 placed radially and evenly relative to the axis of rotation of the device.

In this case, the housing 1 is equipped with an annular extension 6 with a chamfer 7 from the side of the mandrel 3 and longitudinal samples 8, each of which is made in the form of a connected radial 9 and tangential 10 planes, and the radial plane 9 is turned in the direction of rotation.

The mandrel 3 is coaxially and rigidly connected to the housing 1, overlapping the washing channel 2, and is provided with a central hole 11 in communication with the washing channel 2.

The channels 4 of the mandrel for removing chips are made in the form of radial, expanding to the periphery of the end channels located at the cutting elements 5 in the direction of rotation and communicated with the flushing channel 2 technological holes 12 located closer to the center of rotation of the mandrel 3, and with longitudinal samples 8 grooves 13 on the cylindrical surface of the mandrel 3.

Moreover, the expansion 6 with the chamfer 7 of the housing 1 due to, for example, the inserts 14 deposited on the chamfer 7 is made of a material harder than the material of the shoe (not shown) and less solid than the material of the expandable column (not shown), while the diameter of the expansion 6 and the angle of the chamfer 7 is selected with the possibility of introducing the mandrel 3 into the expandable column when sliding the device along the wall of the well (not shown).

The device operates as follows.

An expandable string of profile and (or) cylindrical pipes with a shoe is lowered into the well during the installation interval on the drill pipe string (not shown), in which excess hydraulic pressure is created, previously pressing them against the well walls.

Next, the complete assembly using the internal thread (not shown) is connected to the downhole equipment (most often screwed onto the lower end of the flare tool) and lowered onto the drill pipe string into the well to the installation interval of the expandable string. Upon reaching the upper end of the expandable string, the drill pipe string with the downhole equipment begins to rotate, expanding (for example, using a flare tool) and tightly pressing the profile and (or) cylindrical pipes of the expandable string to the walls of the well along the entire length.

At the same time, the device for flap opening and destruction of the shoe of the expandable columns due to the transition bevel 7 between the outer surface of the housing 1 and the annular extension 6 allows the device to freely slide along the walls of the well and freely enter the expandable column without damaging its end face, but thanks to the weld-in inserts 14 of material less solid than the material of the expandable column, the device does not damage underexposed hydraulic pressure or transitional (with different diameters) sections of pipes expandable to olonni.

Upon reaching the shoe of the expandable column, the cutting elements 5 of the mandrel 3 of the device are introduced into the shoe material. As the shoe is destroyed, the resulting sludge due to flushing fluid entering the cutting zone through the drill pipe string and then through the inner flushing channel 2, the central 11 and peripheral technological holes 12 of the mandrel 3, through the channels 4 for removing chips, grooves 13 on the cylindrical surface of the mandrel 3 and longitudinal samples 8 of the housing 1, is removed from the well, without interfering with the operation of the device.

As the device operates, longitudinal samples 8 begin to come into operation on the surface of the housing 1, which, thanks to the protruding edges formed by the radial and tangential planes 9, 10, develop an annular channel formed by means of cutting elements 5 in the shoe body, passing the generated sludge through sample 8 and preventing jamming of the device.

Next, expansion 6 begins to work with a chamfer 7 of the housing 1, drilling (or unscrewing by carving) the remains of the shoe using inserts 14, the hardness of which is higher than the hardness of the shoe.

After the device passes through the shoe of the expandable string, it is completed with downhole equipment (flare) to be pressed firmly against the walls of the well. Then the whole layout is raised to the surface. The remains of the shoe that fell on the bottom of the well do not interfere with further drilling.

The technical advantages of the proposed device are to increase its reliability and performance, especially when working in directional and horizontal sections of wells, due to the reliable, due to the stepped design of the device and the transition chamfer on the body, centering, allowing the device to freely slide along the walls of the well and freely enter the expandable columns, as well as reduce the load during the destruction of the shoe, passing it sequentially with both steps, and the presence of washing channels and samples throughout the body of the device eliminates the possibility of jamming of the device and breakage of the cutting elements.

Claims (1)

A device for opening and destroying the shoe of expandable columns, comprising a housing with a flushing channel, a mandrel mounted thereon, equipped with channels for chip removal and bottom cutting elements arranged radially and uniformly with respect to the axis of rotation, characterized in that the housing is equipped with an annular extension with a chamfer from the side mandrels and longitudinal samples, each of which is made in the form of connected radial and tangential planes, with the radial facing in the direction of rotation, and the mandrel is coaxial and rigid о is connected to the housing, blocking the washing channel, and provided with a central hole in communication with the washing channel, while the channels of the mandrel for removing chips are made in the form of radial expanding to the periphery end channels located at the cutting elements along the rotation and communicated with the washing channel with technological holes located closer to the center of rotation of the mandrel, and with longitudinal selections of grooves on the cylindrical surface of the mandrel, the expansion with a chamfer of the body made of more more solid than the material of the shoe and less solid than the material of the expandable column, while the diameter of this expansion and the angle of the bevel are selected with the possibility of introducing the mandrel inside the expandable column when sliding the device along the wall of the well.