CN1711404B - A roller assembly and a rotary roller reamer using the same - Google Patents

Abstract

The present invention relates to a roller assembly (20) for a rotary roller reamer (10). The roller assembly (20) includes a roller pin (22) and a crushing roller (24). The crushing roller (24) is arranged to be mounted on the roller pin (22) and to rotate thereabout. The roller assemblies (20) are connected together to form a single cartridge which can be inserted into the pocket (18) of a rotary roller reamer (10) and secured into the pocket (18) using a single fastening device.

Description

A roller assembly and a rotary roller reamer using the same

technical field

This invention relates to an improved rotary roll reamer and improvements to its various components.

Background technique

During drilling operations, the drill bit is subject to wear and thus the size of the drilled hole will change over time. To ensure that the dimensions of the drilled hole remain accurate, a rotary roller reamer is positioned on the drill string and used to enlarge the borehole to the required size. The inclusion of the rotary roller reamer on the drill string enables the drill bit to be used for long periods of time without having to be replaced, which prevents costly downtime.

The working environment of the rotary roll reamer is very harsh. As a result, the components of the rotary roll reamer require frequent maintenance, repair or replacement. Since downtime is costly, it is desirable to extend the operating life of the rotary roll reamer, thereby reducing downtime for maintenance. It would also be desirable to enable the roller assemblies used in the rotary roller reamer to be quickly and easily removed and replaced from their respective pockets in the reamer body.

SUMMARY OF THE INVENTION The present invention provides an improved rotary roll reamer and its various components.

The invention also provides a pressure equalizing device for equipment.

Contents of the invention

According to a first aspect of the present invention there is provided a rotary roller reamer comprising at least one reamer body for receiving a roller assembly, wherein said roller assembly comprises a plurality of Components of a single assembly in a cavity.

Preferably, said integrated part is secured in said pocket by a single fastening device.

According to a second aspect of the present invention there is provided a roll assembly for a rotary roll reamer, said roll assembly comprising a roll pin and a crushing roll arranged to be mounted on said roll pin and rotate about said roll pin, Where the roller assemblies are joined together to form a single integrated piece that can be inserted into the pocket of a rotating roller reamer.

Preferably, the integrated part is arranged to be secured to the pocket by a single fastening device.

Preferably, said roller assembly further comprises first retaining means for retaining said roller pin within said pocket, said first retaining means comprising a first plug arranged to be connected to a roller pin, so that the roller pin, the crushing roller and the first plug form said single integrated piece which can be inserted into the pocket of the rotating roller reamer.

Preferably, the first plug has a first surface mated to the first end of the roller pin, and a second surface arranged to engage a side wall of the pocket, the side wall of the pocket and the side wall of the pocket. The second surface of the first plug is configured such that the first plug is drawn into the pocket when the roller assembly is secured to the pocket by the fastening device.

Preferably, the roller assembly further comprises second retaining means.

Preferably, a first thrust ring is provided between the roll pin and the first end of the crushing roll and a second thrust ring is provided between the second end of the crushing roll and said second retaining means. Preferably, the first and second thrust rings are sacrificial thrust rings arranged to accommodate thrust loads applied to the crushing roll during use of the rotating roll reamer.

Preferably, the first surface of the first plug is complementary to the first end of the roller pin. Preferably, the first end of the roller pin is formed with an enlarged head.

Preferably, the roller pin comprises a rod formed therein with a central longitudinal blind hole leading to the second end of the roller pin. This hole forms a lubricant reservoir. The hole leads to a side opening extending substantially perpendicularly thereto and to a primary lubricant distribution groove. Preferably, the primary lubricant distribution groove extends substantially longitudinally of the pin, and may take various configurations, for example, a "figure of eight" configuration.

During the rotation of the crushing roll around the roll pin, lubricant can be supplied from the reservoir to the primary lubricant distribution groove through the side opening. As the crushing roll rotates around the pin, lubricant is distributed onto the pin's rod.

Preferably, sealing means are provided between the crushing roller and the rod of the roller pin to prevent lubricant leakage.

Preferably, pressure equalization means are provided in the bores of the roller pins. The pressure equalizing device is arranged to equalize the pressure between the drilling mud around the body of the rotating roller reamer and the lubricant contained in the bore of the roller pin. The pressure equalizing means may comprise a filter, for example a sintered metal filter.

In a preferred embodiment, the first plug is formed as a frustum with a base and a top. Preferably, the frustum has an angle relative to its central longitudinal axis of less than or equal to 7°. Preferably, this angle is about 3°. The bottom of the first plug is arranged to be in the uppermost position in the pocket. The bottom has an outer diameter that is smaller than that of the top.

Preferably, the bottom of the first plug has a bottom surface formed to engage with a mating portion of the pocket. Preferably, the cooperating portion of the pocket comprises a post with a central threaded hole into which the fastener can be screwed.

Preferably, the first plug includes a fastener receiving cavity that opens to the side wall of the first plug and also to the bottom of the first plug. The cavity is configured such that a fastener can pass through the opening in the side wall and be positioned therein. In this position, the front end of the fastener extends through the opening in the base. In this way, the front end of the fastener can be screwed into the threaded hole formed in the cylinder of the pocket.

Preferably, the first plug further includes an elongated screw connection notch formed on a side wall thereof. The screw connection slot is configured to receive the head of a screw connected to the enlarged head of the roller pin.

Preferably, a hole is formed in the top of the first plug and is arranged such that a tool can pass therethrough so that a fastener can be screwed into the hole of the post.

In a particularly preferred form, the fastener is a socket head fastener and the socket head fastener is arranged to be positioned in an upper portion of the fastener receiving cavity. The upper part of the cavity is configured so that when the fastener is screwed into the cylinder of the pocket, the first plug can be drawn into the pocket, and when the fastener is unscrewed, the first plug can be drawn into the pocket. Raise the pocket.

Preferably, the second retaining means comprises a second plug formed as a truncated cone. Preferably, the frustum has an angle relative to its central longitudinal axis of less than or equal to 7°. The angle is preferably about 3°. The second plug has a bottom, a top and sidewalls. The bottom has a larger outer diameter than the top outer diameter and is arranged to be positioned at a lowermost location within the pocket.

A hole is formed in the second plug substantially perpendicular to the longitudinal central axis of the second plug. The hole is arranged to receive the second end of the roller pin. Preferably, the aperture is sized to be a sliding fit with the second end of the roller pin.

Preferably, a small hole is also provided in the side wall of the second plug. The aperture is arranged to facilitate pressure equalization between the lubricant contained in the lubricant reservoir and the slurry surrounding the roll assembly during use.

A protrusion protrudes from the sidewall of the second plug. The protrusion is arranged to engage a complementary shaped groove formed in a portion of the pocket.

According to a preferred embodiment of the present invention, each pocket of the rotary roller reamer comprises a lower tapered slot, a primary cavity, a secondary cavity and an upper tapered slot. Preferably, the upper tapered slot is positioned at the upper hole end of the rotary roller reamer and the lower tapered slot is preferably positioned at the lower hole end of the rotary roller reamer.

The upper tapered socket is arranged to receive the first retaining means. The upper tapered slot comprises a semi-circular frusto-conical seat having an angle less than or equal to 7° relative to the vertical axis of the slot (ie, the axis perpendicular to the longitudinal axis of the rotary roller reamer). This angle is preferably approximately 3°. The socket is tapered such that the smaller diameter of the socket forms part of the bottom surface of the pocket. Tangent to the tapered seat is an inlet guide slot with sides for matching the cone of the tapered seat. The seat extends approximately 270° of arc length, the remainder of the arc length being open to the secondary cavity. The seat preferably extends over an arc length of more than 180°.

A cylinder, in which the fastener of the first plug is preferably arranged to be fixed, is located substantially in the center of the upper tapered socket.

Preferably, the primary cavity (or roll cavity) is configured to provide operating clearance for a crushing roll mounted on a roll pin. The primary cavity forms a constriction compared to the outer diameter of the reamer body. This results in the primary cavity having a depth perpendicular to the longitudinal axis of the reamer body which is less than the depth of the upper and lower tapered sockets.

Preferably, the secondary cavity is formed as a trapezoid with sides narrowed at the bottom of the cavity. The secondary cavity forms a seat for the head of the roller pin.

Preferably, the lower tapered socket is arranged to receive the second retaining means. The lower tapered slot comprises a semicircular frusto-conical seat at an angle less than or equal to 7° relative to the vertical axis of the slot (ie, the axis perpendicular to the longitudinal axis of the rotating roller reamer). The angle is preferably about 3°. The socket is tapered such that the larger diameter of the socket forms part of the bottom surface of the pocket.

A groove or ledge arranged to receive a securing lug of the second plug is formed at the location of the side wall portion of the lower tapered socket. The groove or ledge is preferably substantially crescent-shaped.

According to a third aspect of the present invention there is provided a crushing roll for a rotary roll reamer, said crushing roll comprising a central portion and first and second portions, the central portion having an outer diameter larger than the first and second end portions The outer diameter of the diameter, wherein the central, first and second portions are filled with protruding means.

Preferably, the protruding means are arranged in the central part so that the protruding means overlaps the contact area of the part of the borehole wall being reamed. The protruding means may be arranged on at least one helix around the central portion of the crushing roll. The helix is preferably a left-handed helix. This arrangement plays the role of reducing the thrust load on the vertical plane during the use of the crushing roller.

Preferably, each protruding means comprises a button mounted in a hole formed in the crushing roller. The buttons are preferably semicircular tungsten carbide buttons.

According to a preferred form, the buttons on the central portion are arranged in four rows of eight, and are arranged on a left-handed 3.31699" pitch helix. Each row is separated by an angular displacement of 90°, and each row begins at a point equal to Start with incremental steps of 0.125 x 1/9 of the helix reference curve length. Each protruding device is spaced 1/9 of the helix length apart.

Preferably, located between each helically spaced row is a groove generated on the same helical reference path as the protruding means. The grooves are arranged to provide increased slurry flow through the roll and increase the gap through which debris from the reamer passes.

According to a fourth aspect of the present invention there is provided a rotary roller reamer comprising a reamer body having at least one pocket for receiving a roller assembly comprising pins arranged to be mounted on the Breaking rollers on the pins, sealing means between the pins and the breaking rollers and means for retaining the pins in said pockets, wherein the pins comprise holes with pressure equalizing means located therein essentially for Equalize pressure on seals.

Preferably, the pressure equalizing means is used to equalize the pressure during use between the drilling mud around the body of the rotating roller reamer and the lubricant contained in the bore of the roller pin.

Preferably, the crushing roller is arranged to rotate about a roller pin.

The pressure equalizing means may comprise a filter, for example a sintered metal filter.

According to a fifth aspect of the present invention there is provided a rotary roller reamer comprising a reamer body having at least one pocket for receiving a roller assembly comprising a roller pin and arranged to be mounted on the A crushing roll on a roll pin as described above, wherein the reamer body has a primary outer diameter in a region away from the crushing roll and a secondary outer diameter in a region adjacent to the crushing roll, wherein the secondary outer diameter is greater than the primary outer diameter The outer diameter is reduced to provide stress relief.

According to a sixth aspect of the present invention there is provided a pressure equalization device for a device having at least one seal for sealing a lubricant supply between a first and a second component of said device, said The pressure equalizing means is arranged mounted on the apparatus and is arranged such that it serves to equalize the pressure of the lubricant applied to the first side of the at least one sealing means with the pressure applied to the second side of the at least one sealing means. fluid pressure.

Description of drawings

Embodiments of the present invention are described below by way of illustration only with reference to the accompanying drawings, wherein:

1 is a cross-sectional view of a rotary roll reamer according to one embodiment of the present invention;

FIG. 1A is an enlarged view of the central portion (i.e., pocket and roller assembly) of the rotary roller reamer shown in FIG. 1;

2 is a partial assembled view of a roller assembly adjacent a reamer body having a plurality of pockets according to one embodiment of the present invention;

Figure 3 is a central longitudinal sectional view of the roller assembly shown in Figure 2 mounted in a pocket of a rotating roller;

Figure 3A is a partial cross-sectional view of one end of the roller assembly along a line offset from the centerline of the rotating roller reamer;

Figure 4 is a longitudinal sectional view of the pocket of the rotary roll reamer shown in Figure 3;

5 to 8 are perspective views of a first holding device according to an embodiment of the present invention;

9 to 11 are perspective views of a second holding device according to an embodiment of the present invention;

Figure 12 is a side view of a crushing roll according to one embodiment of the invention;

Fig. 13 is a longitudinal sectional view of the crushing roller shown in Fig. 12;

Figure 14 is an end view of the crushing roll shown in Figure 12;

15 to 17 are views of a roller pin according to one embodiment of the present invention;

Figure 18 is a sectional view showing the attachment of the first retaining means to the attachment screw extending from the enlarged head of the roller pin;

19 is a sectional view showing insertion of the retaining plug into the connecting screw notch of the first retaining device;

20 is a partial cross-sectional view showing the insertion of a roll assembly (i.e., assembled roll assembly) into a pocket of a rotary roll reamer;

Figure 21 is a perspective view of the stabilization strap shown in Figure 1A;

Figure 22 is a front view of the stabilization strap shown in Figure 21; and

FIG. 23 is a side view of the stabilization strap shown in FIG. 21. FIG.

Detailed ways

1 and 1A illustrate a rotary roll reamer 10 according to an exemplary embodiment of the present invention. The rotary roll reamer 10 has an externally threaded end 12 and an internally threaded end 14 . The rotary roller reamer 10 is arranged to be connected to a drill string (not shown). As shown in this embodiment, the externally threaded end 12 is located at the lower hole end of the rotary roller reamer 10 , and the internally threaded end 14 is located at the upper hole end of the rotary roller reamer 10 . It should be clearly understood that the configuration or nature of the various ends of the rotary roll reamer 10 may vary.

The rotary roll reamer 10 includes a tubular reamer body 16 that includes three circumferentially spaced pockets 18 . Located within each pocket 18 is a roller assembly or roller assembly 20 . The pockets 18 are shown equally spaced around the circumference of the reamer body 16 and are located in a portion 16a of the reamer body 16 that has a larger outer diameter than the remainder of the reamer body 16 . Although three pockets 18 are shown, it will be appreciated that arrangements with different numbers and spacings of pockets 18 can be devised.

FIG. 2 better shows the pocket 18 formed in the reamer body 16 . This figure also shows cut-outs or mudways 17 formed between adjacent pockets 18 .

Figure 2 shows the roller assembly 20 in a disassembled condition. The roller assembly 20 includes a roller pin 22, a crushing roller 24, a first retaining device 26, a second retaining device 28, a retaining screw 29, a first thrust ring 30, a second thrust ring 32, a pair of seals 34a and 34b, Pressure equalizer 36 , fastener 38 , a pair of self-locking pins 38 a , attachment screw 70 and retaining plug 72 .

When the elements of the roll assembly 20 are assembled together, they form a single integrated piece that can be secured into the pocket 18 of the rotary roll reamer 10 with fasteners 38 . In use, the crushing roll 24 is arranged to rotate about the roll pin 22 in order to use it to enlarge the sidewall of the borehole through which the rotary roll reamer 10 passes. The performance of each element of the roller assembly 20 and the pocket 18 formed in the reamer body 16 will now be described in more detail.

The configuration of each pocket 18 and the engagement of the roller assembly 20 in its respective pocket 18 is best shown in FIGS. 3 , 3A and 4 . Each pocket 18 includes a lower tapered socket 40 , a primary cavity 42 , a secondary cavity 44 and an upper tapered socket 46 . The lower tapered slot 40 is located at the lower hole end of the rotary roller reamer 10 and the upper tapered slot 46 is located at the upper hole end of the rotary roller reamer 10 . The lower tapered socket 40 is arranged to receive the second retaining device 28 and the upper tapered socket 46 is arranged to receive the first retaining device 26 . The primary cavity 42 is arranged to receive the roll pin 22 and the crushing roll 24 mounted on the roll pin. The primary cavity 42 is sized and configured to provide operational clearance for the crushing roll 24 during use of the rotary roll reamer 10 . The secondary cavity 44 forms a seat for the head 22 a of the roller pin 22 .

The lower tapered socket 40 comprises a semicircular truncated conical seat having an angle less than or equal to 7° relative to the vertical axis of the pocket 18 (ie, the axis perpendicular to the longitudinal axis of the rotary roller reamer 10). As shown, this angle is approximately 3°. The diameter of the lower tapered socket 40 tapers so that the larger diameter of the socket 40 forms part of the bottom surface 18 a of the pocket 18 . Tangent to the tapered seat is an inlet guide slot 40a with sides matching the taper of the tapered seat.

A semicircular groove 40 b is formed at the lower portion of the lower tapered socket 40 and coincides with the bottom surface 18 a of the pocket 18 . The groove 40b is a fixed groove for receiving a complementary shaped protrusion 28k formed on the second holding means 28 . The functions of the fixing groove 40b and the protrusion 28k will be described in more detail later. the

Four carbide inserts 18b are mounted in a portion of the bottom surface 18a of the lower tapered socket 40 so as to be positioned below the head 22a of the roller pin 22 . Carbide slug 18b is provided to prevent wear of bottom surface 18a of pocket 18 due to movement of head 22a during use of rotary roll reamer 10 .

As best shown in FIG. 4 , the primary cavity 42 forms a constriction compared to the outer diameter of the reamer body 16 . Furthermore, the bottom surface 18a of the primary cavity 42 is gradually lowered in the direction of the centerline of the reamer body 16 . Accordingly, the primary cavity 42 has a depth perpendicular to the longitudinal axis sufficient to provide a working gap for the crushing roller 24 . Additionally, the outer diameter of the reamer body 16 is reduced or "necked" in the region adjacent the lower and upper tapered sockets 40 , 46 compared to the outer diameter of the reamer body 16 in the region. This necked down configuration of the reamer body 16 provides stress relief in this area of the pocket 18 .

The secondary cavity 44 is formed in a trapezoidal shape with sides narrowed at the lower hole end of the cavity 44 .

The upper tapered socket 46 includes a semi-circular frusto-conical seat having an angle less than or equal to 7° relative to the vertical axis of the socket 46 . As shown, this angle is approximately 3°. The diameter of the upper socket 46 tapers so that the smaller diameter of the socket 46 forms part of the bottom surface 18 a of the pocket 18 . The seat extends approximately 270° of arc length, the remainder of the arc length opening into secondary cavity 44 . Post 52 is located substantially in the center of upper tapered slot 46 . Post 52 includes a hole 54 threaded to receive fastener 38 . Alternatively, a threaded insert 54a may be positioned in bore 54 as shown.

5 to 8 show the first holding device 26 . The first retaining means 26 is formed as a first plug 26 and is arranged to be received within an upper tapered socket 46 . The first plug 26 is formed as a truncated cone. The frustum has an angle with respect to its central longitudinal axis of less than or equal to 7° and includes a base 26a and a top 26b. As shown, the frustum has an angle of approximately 3°. The bottom 26a is arranged to be positioned at the lowermost portion of the lower tapered socket 46 . The bottom 26a has an outer diameter that is smaller than the outer diameter of the top 26b. The bottom surface of the bottom 26 a is shaped to engage the bottom surface 18 a of the pocket 18 in this region of the upper tapered socket 46 . More specifically, base 26a is shaped such that it can mate with post 52 .

The first plug 26 includes a fastener receiving cavity 26c that opens to the side wall 26d and also to the bottom 26a of the first plug. Cavity 26 c is configured to position fastener 38 therein and to secure front end 38 b of fastener 38 within hole 54 formed in post 52 . At the location of the top 26b of the first plug 26 there is a hole 26e configured to allow the working end of a tool to pass therethrough. This enables the fastener 38 to be threaded into and out of the hole 54 of the post 52 .

Formed in the top 26b of the first plug 26 is a pair of holes arranged to be received from the locking pin 38a. Self-locking pin 38a is configured to properly position and lock fastener 38 within fastener receiving cavity 26c.

The side wall 26d of the first plug 26 also includes an elongated attachment screw notch 26f capable of connecting the first plug 26 to an attachment screw protruding from the enlarged head 22a of the roller pin 22. 70. The attachment screw slot 26f includes a threaded upper portion 26f' arranged to receive a threaded retaining plug 72 (Fig. 19). Prior to receiving retaining plug 72, threaded upper portion 26f' is sized to allow head 70a of attachment screw 70 to pass therethrough. In this way, the head 70a of the attachment screw 70 can be inserted into the attachment screw slot 26f, and the shank of the screw 70 can then be moved along the length of the slot 26f. The connection between the screw 70 and the first plug 26 will be described in more detail later.

As best shown in FIG. 3, fastener 38 is a socket head fastener. The head of the fastener 38 is arranged to be positioned in the upper part of the cavity 26c, so that when the fastener 38 is screwed into the post 52, the first retaining means 26 can be drawn into the lower tapered slot 46, and when When the fastener 38 is unscrewed, the first retaining device 26 can be lifted out of the upper tapered socket 46 . The configuration of the side walls of the lower tapered slot 46 and the shape of the head 22 a of the roller pin 22 facilitate this action of the first retaining means 26 . When the first retaining device 26 (first plug 26 ) is connected to the roller pin 22 , movement of the first plug 26 into and out of the upper tapered slot 46 causes movement of the entire roller assembly 20 into and out of the pocket 18 .

9 to 11 show the second holding device 28 . The second holding means 28 or the second plug is formed as a frustum. The frustum has an angle less than or equal to 7° with respect to its central longitudinal axis. As shown, this angle is approximately 3°. The second plug 28 has a bottom 28b, a top 28c and a side wall 28d. The bottom 28b has a larger outer diameter than the top 28c and is arranged to be positioned lowermost within the upper tapered socket 40 . In the planar portion of the side wall 28d of the second plug 28, a hole 28e is formed. Bore 28e extends substantially perpendicular to its central longitudinal axis. The hole 28e is arranged to receive the second end 22b of the roller pin 22 . The hole 28e is sized to be a sliding fit with the second end 22b of the roller pin 22 .

A screw hole 28f is formed in the bottom 28b of the second plug 28 . The threaded hole 28f is arranged to receive a retaining screw 29 that positions the second end 22b of the roller pin 22 within the second plug 28 . The engagement of retaining screw 29 with roller pin 22 will be described in more detail below.

In the side wall 28d of the second plug 28, a small hole 28j is formed. The function of the small hole 28j will be explained below.

As described above, the second plug 28 has the protrusion 28k formed at the lower portion thereof. The protrusion 28 k is arranged to engage with a fixing groove 40 b formed in the lower tapered socket 40 . This engagement serves to better retain the roller assembly 20 in the pocket 18 .

12 to 14 show the crushing roller 24 . The crushing roller 24 is formed as a hollow cylindrical member having a central bore sized to receive the shank of the roller pin 22 . The breaker roll 24 has a reduced diameter portion at each end for primary engagement between the breaker roll 24 and the wellbore wall. The secondary engagement diameter is formed between the primary engagement portions, and a plurality of buttons 60 (not shown in FIGS. 12 to 14 ) are distributed. Buttons 60 are preferably semicircular tungsten carbide buttons, each of which fits within a bore 62 . According to a preferred embodiment, the carbide buttons 60 are arranged in four rows of eight on a left-handed 3.31699" pitch helix. Each row is separated by an angular displacement of 90°, and the starting point of each row Start with incremental steps equal to 0.125 x 1/9 the length of the helix reference curve. Each button 60 is spaced apart by 1/9 the length of the helix curve.

Those skilled in the art will appreciate that the above arrangement of buttons 60 on the crushing roll 24 provides a very efficient use of the buttons in the carbide field, thereby significantly reducing the use of carbides. The reduction in carbide usage is also expected to reduce the torque load on the drill string. It should further be understood that other arrangements of carbide buttons on the crushing roll may also be used. The carbide buttons are preferably arranged such that they provide complete coverage of the enlarged wall portion of the well or borehole during use. That is to say, the contact area of the respective carbide button overlaps the enlarged part of the borehole.

Located between each helically spaced row of buttons is a groove 64 . There are four grooves 64 and they are created on the same helical reference path as holes 62 . The grooves 64 are arranged to allow increased slurry flow through the crushing rolls 24 and to increase the clearance through which crushing debris from the rotating roll reamer 10 can pass.

The primary engagement diameter included at each end 24a, 24b of the crushing roll 24 enables the rotary roll reamer 10 to be used bi-directionally (ie, in its upper and lower holes). There are seven holes 62a in each primary diameter for inserting reinforced domed tungsten carbide buttons 60a. The holes 62a are equally spaced and drilled around the circumference in a surface perpendicular to the central axis of the roll.

As shown in FIG. 12, a reinforcement hole 62b drilled through to the center hole is formed on each primary engagement diameter. Each bore 62b is internally threaded and arranged to receive a pressure plug 63 . Each hole 62b has the dual function of a lubricating oil injection port and a cleaning port. The use of the pressure plug 63 will be explained in more detail later.

As shown in Figure 13, formed in the central bore wall of the crushing roll 24 is a pair of seal retaining grooves 66 arranged to receive corresponding seals 34a, 34b. As shown, the seals 34a, 34b are simple O-rings. However, other types of seals may also be used.

As shown in FIG. 13, there is a reinforcing annular groove 24c in the middle of both ends of the hole of the crushing roller 24. As shown in FIG. Each slot 24c is arranged to receive a stabilization strap 75 . As better shown in Figure 21, each stabilizing strap 75 is a strap that is broken at point A so as to provide clearance between the corresponding ends 75a, 75b of the strap. The ends 75a, 75b terminate at an angle of approximately 45° (see FIG. 23). Terminations at other angles are contemplated.

Each stabilizing strap 75 is sized to provide a minimal loose fit around the rod of the roller pin 22, and floats in the corresponding slot 24c. Thus, the stabilizing belt 75 can rotate with the roller pin 22 or with the crushing roller 24 .

Preferably, such stabilizing straps 75 are manufactured from a material having reasonable stiffness and a relatively low coefficient of friction. This material can be manufactured from DuPont in the form of Teflon (TEFLON) The trademark is a fluoropolymer selected from the commercially available polytetrafluoroethylene (PTFE) series. But, better yet, strengthen the material by adding fillers such as glass, bronze, or nickel. Bronze-added PTFE is the ideal material.

In this form, the stabilizing strap 75 will assist the roller pin 22 in substantially stabilizing rotation about its longitudinal axis and along its entire length. In this regard, in some cases, the seals 34a, 34b may be sensitive to end-to-end runout of the roller pins 22, for example, runout typically due to the shock pressure of a reasonable magnitude to which the roller assembly 20 is subjected during operation. . Thus, the increased use of this general type of stabilizing strap 75 facilitates smooth operation of the roller assembly 20 .

15 to 18 show the roller pin 22 . Roller pin 22 includes a longitudinal central bore 22c (best shown in FIGS. 3 and 15 ) leading to lower end 22b. The hole 22c in the shaft of the roller pin 22 forms a lubricant reservoir. The side opening 22d extends between the lubricant reservoir 22c and the primary lubricant distribution groove 22e. The primary lubricant distribution groove 22 e extends in the longitudinal direction of the roller pin 22 . As best shown in Figures 16 and 17, the primary lubricant distribution groove 22e is formed in a "figure 8" configuration.

It will be appreciated that the lubricant reservoir 22c enables lubricant to be stored in the roller pin 22 and continuously supplied to the distribution channel 22e through the side opening 22d during the rotation of the crushing roller 24 about the roller pin 22 . As the crushing roller 24 rotates about the roller pin 22 , lubricant is distributed onto the rod of the roller pin 22 . The seals 34a, 34b keep the lubricant on the rod of the roller pin 22 .

The second side opening 22i is located adjacent the second end 22b of the roller pin 22 and intersects the lubricant reservoir 22c. The side opening 22i leads to the groove 22j. The functions of the groove 22j and the side opening 22i will be described later.

A transverse retaining notch 22g is also formed adjacent the second end 22b of the roller pin 22 . The holding notches 22g are arranged such that the holding screws 29 in the second holding means 28 can be positioned in the holding notches 22g. In this way, the roller pin 22 can be oriented relative to the second holding device 28 . The use of the retention notch 22g enables limited rotation of the roller pin 22 after connection to the first plug 28 .

As best shown in Figures 3 and 20, the pressure equalizing device 36 is positioned in stationary abutment against a counterbore formed in the lubricant reservoir 22c. The portion of lubricant reservoir 22c to the right of pressure equalizing device 36 (as shown in FIG. 3 ) opens to bore 28e of second plug 28 when roller assembly 20 is positioned in pocket 18 . The second side opening 22i of the roller pin 22 leads to a slot 22j ( FIG. 20 ), which in turn is aligned with an aperture 28j formed in the second plug 28 . The small hole 28j of the second plug 28 opens into the area surrounding the crushing roller 24 . It will therefore be appreciated that there is a pressure flow path from the area surrounding the crushing roll 24 to this static pressure equalizing device 36 .

The function of the pressure equalizing device 36 is to ensure that during the reaming operation, the pressure of the lubricant in the bearing cavity (that is, the gap between the roller pin 22 and the crushing roller 24) is the same as that completely surrounding the rotating roller during the reaming operation. The pressure of the drilling mud of the hole punch 10 is substantially equal. It is important to equalize this pressure to prevent the seals 34a, 34b from bursting.

As shown, the pressure equalizing device is a rigid filter 36 . In one embodiment, filter 36 is a sintered metal filter. A sintered metal filter may have an alloy composition of 68% copper, 27% nickel and 5% tin with a micron capture equal to or about 30 μm. Filter 36 may take other compositions.

As best shown in FIGS. 3 , 18 and 19 , the head 22 a of the roller pin 22 is shaped to mate with the side wall 26 b of the first plug 26 . Therefore, the head 22a is configured as a side trapezoidal solid structure with conical undercuts on the outer surface.

The head 22a includes a blind hole 22f that coincides with the long axis of the roller pin 22 . The hole 22f is threaded so as to be able to be connected with the connecting pin 70 . This connection will be described in detail later.

The first thrust ring 30 is formed as a solid ring of low friction metal or reinforced polymer which bears against the roll side surface of the head 22a of the roll pin 22 and the surface of the first end 24a of the crushing roll 24 . The first thrust ring 30 is designed to withstand the vertical thrust on the crushing roll 24 from the sidewall of the borehole due to the upward rotational stroke of the rotating roll reamer 10 . The first thrust ring 30 is a sacrificial thrust ring.

The first thrust ring 30 has an internal O-ring seal 30 a arranged to provide a small amount of shock absorption between the inner diameter of the thrust ring 30 and the shaft of the roller pin 22 . The O-ring seal 30a also functions to stop the flow of drilling mud.

The second thrust ring 32 is a solid ring formed as a low friction metal or reinforced polymer that bears against the second end 24b of the crushing roll 24 and the surface of the second plug 28 . The second thrust collar 32 is designed to withstand the vertical thrust on the crushing roll 24 from the sidewall of the borehole due to the downward rotational stroke of the rotating roll reamer 10 within the borehole. The second thrust ring 32 is a sacrificial thrust ring.

The second thrust ring has an internal O-ring seal 32 a arranged to provide a small amount of shock absorption between the inner diameter of the thrust ring 32 and the shaft of the roller pin 22 . The O-ring seal 32a also acts to prevent the flow of drilling mud.

The O-ring seals 32a, 30a are preferably fabricated from a fluorinated elastomeric compound.

The assembly process of the roller assembly 20 is as follows. Slide the first thrust ring 30 along the shaft of the roller pin 22 until it abuts against the head 22a of the roller pin 22 . The crushing roll 24 with the seals 34a, 34b and stabilizing band 75 in place and fitted with carbide tip 60 is then slid over the rod of the roll pin 22 until the first end 24a of the crushing roll 24 abuts against the first stop. Push ring 30. Then, the filter 36 is installed on the counterbore of the lubricant reservoir 22c.

At this stage, lubricating oil is injected into the crushing roll 24 through one of the holes 62b ("first hole 62b"). The lubricating oil is injected until the lubricating oil flows through the hole 62b in the other primary meshing diameter of the crushing roll 24 ("second hole 62b"). Then, the pressure plug 63 is installed to seal the second hole 62b.

Continue to inject lubricating oil until the lubricating oil flows through the lubricant reservoir 22c and through the pressure equalizing filter 36 . At this point, the lubricating oil injection device is removed, and the pressure plug 63 is fitted into the first hole 62b.

The second thrust ring 32 is then positioned on the rod of the roller pin 22 until it abuts against the second end 24b of the crushing roller 24 . Finally, the second plug 28 is slid onto the end of the roller pin 22 so that the end of the second thrust ring 32 is in flush alignment with the planar portion of the side wall 28d of the second plug 28 . The retaining screw 29 is then fitted into the threaded hole 28f and tightened inwardly so that it is positioned in the retaining notch 22g formed in the shaft of the roller pin 22 .

Next, the fastener 38 is inserted into the fastener receiving cavity 26c of the first plug 26 and secured in place by the self-locking pin 38a.

Then, the steel ball 71 is put into the blind hole 22f. Next, the attachment screw 70 is screwed into the hole 22f until it firmly seats the steel ball 71. This operation ensures a constant depth of engagement of the first plug 26 with the roller pin 22 . Next, the head 70a of the attachment screw 70 is passed through the upper portion 26f' of the attachment screw notch 26f in the first plug 26. The connection between the first plug 26 and the roller pin 22 is maintained by inserting the retention plug 72 into the threaded upper portion 26f' of the connection screw slot 26f. The retaining plug 72 prevents the head 70a of the attachment screw 70 from being unintentionally withdrawn from the attachment screw notch 26f.

The positioning of the attachment screw 70 in the attachment screw notch 26f of the first plug 26 is best shown in FIG. 18 . Insertion of the retention plug 72 in the threaded upper portion 26f' of the attachment screw notch 26f is best shown in Figure 19 .

As will become apparent, the connection between the head 22a of the roller pin 22 and the first plug 26 enables a limited articulation of the first plug 26 relative to the roller pin 22 while still ensuring Proper alignment of the plug 26 relative to the roll pin 22 when the member 20 is fitted into the pocket 18 of the rotary roll reamer 10 is provided.

Once the elements of the roller assembly 20 are assembled, the roller unit forms a single unit that is easily inserted into the pocket 18 of the rotary reamer 10 as will be explained.

The roll pack 20 fits within the pocket 18 of the rotary roll reamer 10 as follows. First, the roller assembly 20 is held horizontally so as to position the second plug 28 in an advanced position facing the end of the lower tapered slot 40 . Then, the roller assembly 20 is inclined toward the bottom surface 18 a of the pocket 18 . Next, the second plug 28 is lowered into the cavity 18 until the second plug 28 contacts the bottom surface 18 a of the cavity 18 . The roller assembly 20 is then slid forward and down into the pocket 18 until the second plug 28 is seated in the lower tapered slot 40 .

In positioning the second plug 28 in the lower tapered socket 40, the first plug 26 self-aligns with respect to the roller pin 22 and the upper tapered socket 46 so that it is properly positioned in the pocket 18, Ready to hold in place with fasteners 38. This "self-aligning" property of the first plug 26 is a result of the connection properties between the first plug 26 , the connecting screw 70 , the steel ball 71 and the head 22 a of the roller pin 22 .

Then, a hex screwdriver is inserted into the first plug 26 through the hole 26d and the fastener 38 is screwed into the threaded hole 54 of the post 52 formed in the bottom surface 18a of the pocket 18 . As the fastener 38 is threaded into the bore 54 , the first plug 26 is drawn into the upper tapered socket 46 . FIG. 20 shows the roll assembly 20 fitted into the pocket 18 of the rotary roll reamer 10 .

Those skilled in the art will appreciate that a different number of pockets 18 may be provided on the reamer body 16 . Furthermore, although the pockets 18 are described as being equally spaced around the circumference of the reamer body, this need not always be the case. For example, they can be spaced by exponential or logarithmic values.

It should also be appreciated that the crushing roll 24 may include different arrangements and numbers of primary engagement diameters (ie, may take the form of multiple steps), carbide buttons, grooves, and helices.

The above-described embodiments of the present invention are beneficial because:

1. Each roller assembly 20 is retained in its corresponding pocket 18 with a single locking device (eg, bolt 38).

2. Since the roller assemblies 20 are assembled as a single "one" assembly, each roller assembly 20 can be easily assembled into and removed from its corresponding pocket 18. This enables rapid insertion and removal of the roller assembly 20 into and out of the pocket 18 , thus helping to minimize downtime required for servicing the rotary reamer 10 .

3. The arrangement of the first retaining means (first plug) 26 is such that tightening of the fastener 38 can pull the first retaining means 26 into the pocket 18 and loosening of the fastener can pull the first retaining means 26 into the recess 18. 26 is lifted, thereby lifting the entire roller assembly 20 out of the pocket 18. This ensures that the roller assembly 20 can be removed even under the worst conditions on site.

4. The necked portion of the reamer body 16 adjacent to the crushing roll 24 facilitates the relief of torsional stresses that would otherwise be concentrated in this area of the reamer body 16 . The constriction also enables more mud to flow through the primary mud channels sandwiched between the pockets 18 and through and over the pockets 18 . The necked portion also provides a one-way path connecting each of the mud passages should any of the mud passages become blocked during use of the rotary roll reamer 10 .

5. The placement of the carbide buttons 60, 60a on the crushing roll 24 reduces the amount of carbide used while maintaining the necessary performance. In addition, it is contemplated that the placement of carbide buttons may reduce torque loads in the drill string.

6. The described pressure equalization arrangement and in particular the use of the filter 36 in the lubricant chamber 22c increases the operational life of the roller assembly 20 .

7. The load force on the rotating roller reamer is essentially longitudinal, not transverse. This results in a longer working life of the rotary roll reamer.

8. During use, the rotary roller reamer rotates to the right (ie, clockwise when looking down the wellbore). The breaker roll 24 will rotate to the left as it engages the borehole. As the drill bit on the end of the drill string wears down in diameter through normal operation, the reamer, through its rolling and crushing action, maintains the integrity of the borehole diameter specification during periods exceeding the capacity of the drill bit to maintain The required hole size. Thus, the use of a roller reamer according to embodiments of the present invention reduces the frequency with which the drill string is completely removed from the wellbore for drill bit replacement.

9. The roll assembly 20 can be provided on site, ready to use, without any further component assembly.

The embodiments are described by way of illustration only, and various modifications are included within the spirit and scope of the invention.

Claims (28)

CLAIMS 1. A roll assembly for a rotary roll reamer, said roll assembly comprising a roll pin, a roll arranged to fit on said roll pin, a first retaining means and a second retaining means, characterized in that, Said roller pin has a head arranged to be hingedly connected to said first holding means and an end arranged to be received in a hole formed in said second holding means, said end being fixed to said holding means by means of fixing means. said second holding means, wherein said roller pin, roller, first holding means and second holding means are arranged to be connected together so as to form insertable pockets formed in said rotating roll reamer and An integrated part secured to the pocket, the integrated part being arranged to be secured to the pocket by means of a fastener. 2. A roller assembly according to claim 1, wherein said first retaining means comprises a first plug having a first surface cooperating with the head of a roller pin and arranged to engage said a second surface engaging the sidewall of the pocket, the sidewall of the pocket and the second surface of the first plug being configured, when the fastener is used with the second When engagement of a plug secures the integral part to said pocket, the first plug is drawn into the pocket. 3. The roller assembly of claim 2, wherein the first plug has a fastener receiving cavity through a side wall and a bottom of the first plug, the fastener receiving cavity being arranged to receive a fastener. firmware. 4. The roller assembly of claim 3, wherein the first plug further includes an elongated screw connection notch configured to receive a screw arranged to connect to a roller pin head. head. 5. The roller assembly of claim 4, wherein the head of the screw is movable along the screw connection slot to provide an articulated connection between the head of the roller pin and the first plug . 6. The roller assembly of claim 5, further comprising a retaining plug in the screw connection notch to prevent inadvertent disengagement of the screw head from the notch. 7. A roller assembly according to any one of claims 2-6, wherein the first plug further comprises a hole leading to the fastener receiving cavity, the hole being arranged to enable a tool to pass therethrough to enable the fastener to be threaded and secured to the mating portion of the pocket. 8. The roller assembly of any one of claims 2-6, further comprising a first thrust ring positioned between the roller pin and the first end of the roller, and a first thrust ring positioned between the second end of the roller and the first end of the roller. A second thrust ring between the two retaining devices. 9. The roller assembly of claim 8, wherein the first and second thrust rings are sacrificial thrust rings. 10. The roller assembly of claim 8, wherein the first surface of the first plug is complementary to the first end of the roller pin. 11. The roller assembly of claim 10, wherein the roller pin comprises a rod having a central longitudinal blind hole formed therein that leads to the second end of the roller pin. 12. The roll assembly of claim 11, wherein the blind hole forms a lubricant reservoir, and the blind hole includes a side opening extending substantially perpendicular to the blind hole and leading to a primary lubricant distribution groove. 13. The roll assembly of claim 12, wherein the primary lubricant distribution groove extends substantially longitudinally of the roll pin. 14. The roll assembly of claim 11, further comprising sealing means provided between the crushing roll and the rod of the roll pin. 15. The roll assembly of any one of claims 2-6, wherein the first plug includes a bottom having a bottom surface shaped to engage a mating portion of a pocket of a rotary roll reamer. 16. A roller assembly according to any one of claims 1-6, wherein the second retaining means comprises a second plug having a central longitudinal axis formed substantially perpendicular to the second plug large holes arranged to receive the ends of the roller pins. 17. The roll assembly of claim 16, wherein the second plug further includes a small hole having a first end that opens into the large hole, and the small hole opens when the roll assembly is assembled into a rotating roll reamer. When passing to the second end of the area surrounding the roller. 18. A roller assembly according to claim 17, wherein the second plug further comprises a projection arranged to engage a complementary shaped groove formed in a portion of the pocket. 19. A roller assembly according to claim 18, wherein the second plug further comprises an aperture arranged to receive said securing means for securing the end of the roller pin in the second plug. 20. A roller assembly as claimed in claim 19, wherein the securing means comprises retaining screws. 21. The roller assembly of claim 17, wherein the roller pin includes a side opening extending between the lubricant reservoir and the aperture in the second plug. 22. The roller assembly according to any one of claims 1-6, wherein said roller comprises a central portion and first and second end portions, the central portion having an outer diameter greater than that of the first and second portions Outer diameter, wherein the central portion, the first and the second portion are filled with raised means. 23. A roller assembly as claimed in claim 22, wherein the protruding means is positioned around the central portion such that the contact area of the protruding means overlaps a part of the wall of the enlarged borehole. 24. A roll assembly according to claim 23, wherein the central portion upper projection means are arranged in four rows of eight and are arranged on a left-handed 3.31699" pitch helix, each row being separated by an angular displacement of 90° , the starting point of each row begins with an incremental step equal to the length of the helical reference curve of 0.125×1/9, and each protruding device is spaced 1/9 of the length of the helical curve. 25. A roller assembly as claimed in claim 24, wherein the groove is located between each helically spaced row, the helically spaced row being created on the same helical reference path as the protrusion means. 26. The roller assembly according to any one of claims 1-6, wherein said roller comprises at least one lubricant inlet hole and plug means for plugging said lubricant inlet hole, said lubricant inlet hole The holes are arranged to provide lubricant to the roller pins. 27. A rotary roll reamer comprising a reamer body, and at least one roll assembly according to any one of claims 1-6, wherein the reamer body has a at least one pocket of the at least one roller assembly. 28. The rotary roller reamer of claim 27, wherein each said roller assembly is secured to its respective pocket by a single fastener.

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