A CUTTING INSERT FOR USE IN A WELLBORE MILLING TOOL

Abstract: A cutting insert for use in a wellbore milling tool, characterised in that said cutting insert is provided with means (385, 375, 398, 397, 476, 478) which will co-operate with another cutting insert to inhibit inadvertent dislocation thereof. There is also disclosed a cutting insert for use in a wellbore milling tool, said cutting insert comprising a body having a base which can be mounted on a surface of said wellbore milling tool and a cutting surface bounded by linear boundaries which extend from a first edge of the cutting insert to a second edge thereof said cutting surface having a plurality of ridges (349) which extend between said linear boundaries, characterised by four cutting surfaces, the linear boundaries of which are substantially parallel to one another.

Description: A Cutting Insert for Use in a Wellbore Milling Tool This invention relates to a cutting insert for use in a wellbore milling tool and to a wellbore milling tool provided with a plurality of such cutting inserts. In our PCT Patent Application PCT/GB96/02355 which was published under Publication No. W097/11251 after the priority date hereof we describe and claimed a cutting insert for use in a wellbore milling tool, said cutting insert comprising a body having a base which can be mounted on a surface of said wellbore milling tool and a cutting surface bounded by linear boundaries which extend from a first edge of the cutting insert to a second edge thereof, said cutting surface having a plurality of ridges which extend between said linear boundaries, characterised by at least two cutting surfaces the linear boundaries of which are substantially parallel to one another. In use these cutting inserts are sewed to a wellbore milling tool. We are concerned that, in use, certain cutting inserts may be dislodged from the wellbore milling tool. Once one cutting insert is dislodged others could follow leading to "bald" areas on the wellbore milling tool. In order to help reduce this perceived problem the present invention proposes to provide each cutting insert with means which will co-operate with another cutting insert to inhibit inadvertent dislocation thereof. Whilst the present invention was developed for use with the aforedescribed cutting inserts it is applicable to cutting elements in general. According to the present invention there is provided a cutting insert for use in a wellbore milling tool, characterised in that said cutting insert is provided with means which will co-operate with one another to inhibit inadvertent dislocation of a cutting element. Further features are set out in Claims 2 to 24. * * * Since our Patent Application PCT/GB96/02355 we have also developed two new types of cutting inserts which are also described and subsequently claimed in Claims 25 et seq. The present invention, in certain embodiments, discloses a cutting insert for a tool for wellbore milling operations, the cutting insert having a body having a top, a bottom, and a base, and a plurality of cutting surfaces on the top of the body, at least one of the cutting surfaces at a different height above the base than the other cutting surfaces, each cutting surface defined by linear boundaries extending from a first edge of the cutting insert to a second edge of the cutting insert, and the linear boundaries parallel to each other, the plurality of cutting surfaces comprising four cutting adjacent surfaces disposed side-by-side including a first cutting surface, a second cutting surface, a third cutting surface, and a fourth cutting surface, and at least two of the cutting surfaces at a substantially same height above the base; such a cutting insert with at least one chipbreaking indentation on each cutting surface; such an insert wherein the second cutting surface is disposed between the first and third cutting surfaces, the third cutting surface is disposed between the second and fourth cutting surfaces, the first and third cutting surfaces are at a substantially same height above the base, and the second and fourth cutting surfaces are at a substantially same height above the base different from that of the first and third cutting surfaces. The present invention, in certain embodiments, discloses an array of cutting inserts with a plurality of adjacent inserts, each insert with interlinking apparatus comprising a projection on each of a first portion of the inserts and a projection recess on each of a second portion of the inserts, and the inserts arranged so that a projection on one insert is positioned in a projection recess of an adjacent insert. For a better understanding of the present invention reference will now be made, by way of example, to the accompanying drawings, in which: - Fig. 1 is a perspective view of part of a wellbore milling tool provided with the cutting inserts shown in Fig. 1A and 3A of W097/11251; , Fig. 2A is a top view of a first embodiment of a cutting insert according to the present invention; Fig. 2B is a cross-section view along line 2B-2B of Fig. 2A; Fig. 2C is a cross-section view along line 2C-2C of Fig. 2A; Fig. 2D is a detail view of the encircled part of Fig. 2C; Fig. 3A is a top view of an embodiment of a cutting insert according to the present invention; Fig. 3B is a cross-section view along line 3B-3B of Fig. 3A; Fig. 3C is a cross-section view along line 3C-3C of Fig. 3A; Fig. 3D is a detail view of the encircled part of Fig. 3C; Fig. 4A is a top view of a third embodiment of a cutting insert according to the present invention; Fig. 4B is a cross-section view along line 4B-4B of Fig. 4A; Fig. 4C is a cross-section view along line 4C-4C of Fig. 4A; Fig. 4D is a detail view of the encircled part of Fig. 4C; * * * Fig. 5 is a cross-section through three type A cutting inserts according to the present invention; Fig. 6 is a cross-section through three type B cutting inserts according to the present invention; Fig. 7 is a cross-section through three type C cutting inserts according to the present invention; Fig. 8 is a cross-section through three type D cutting inserts according to the present invention; Fig. 9A is a plan view of a type E cutting insert according to the present invention; , Fig. 9B is a side elevation of the cutting insert shown in Fig. 9A; Fig. 9C is a plan view of a type F cutting insert according to the present invention; Fig. 9D is a side elevation of the cutting insert shown in Fig. 9C; Fig. 9E is a plan view showing two type E cutting inserts placed side-by-side and restrained by two type F cutting inserts; Fig. 10A is a plan view of a type G cutting insert according to the present invention; Fig. 10B is a plan view of a type H cutting insert according to the present invention; Fig. IOC is a plan view of a type I cutting insert according to the present invention; Fig. 10D is a plan view of a type J cutting insert according to the present invention; and Fig. 10E is a plan view showing type G, H, I and J cutting inserts interconnected. Fig. 1 shows a blade L (or mill body portion) with a layer of alternating cutting inserts 10 and 60. The pattern may be extended in any direction to include additional inserts 10 and 60. It will be noted that two different types of cutting inserts are required to make a regular cutting surface. Figs. 2A-2D show a cutting insert 300 with a body 305 and four sides 301, 302, 303, and 304. The body 305 is shown as square with rounded corners (as viewed from above), but it may be any desired shape, e.g. rectangular, circular, oval, elliptical, triangular or trapezoidal. The top surface of the body 305 has two cutting surfaces 306 and 307, each of which has a plurality of chipbreaking indentations 308 formed therein with ridges 309 therebetween. In one particular embodiment, the cutting insert 300 has these dimensions in inches: m .05 p .218 t .083 w .302 n .375 r .01 u .156 y .063 o .005 s .375 v .229 z .015 The angle q is about 1.8 degrees; the radius at x is about .04 inches; and the radius 1 is about .03 inches. It will be noted that the cutting inserts 300 can be arranged of a blade to form a regular cutting surface. Figs. 3A-3D show a cutting insert 320 with a body 325 and four sides 321, 322, 323, and 324. The body 325 is shown as rectangular with rounded corners, (as viewed from above), but it may be any desired shape, e.g. square, circular, oval, elliptical, triangular, or trapezoidal. The top surface of the body 325 has two cutting surfaces 326 and 327 each with a plurality of chipbreakers 328 formed therein with ridges 329 there- between. One particular embodiment of the cutting insert 320 has the following dimensions in inches: E .04 H .083 K .302 N .521 Q .063 F .3383 I .156 L .375 0 .015 R .005 G .01 J .229 M .448 P .2425 The angles noted are as follows, in degrees: S 1.3 T 3.7 U 11.3 V 91.3 W 40 The radiuses noted are as follows, in inches: X .04 Y .01 Z .03 Corner radiuses (as viewed from above) are, in certain preferred embodiments 0.15 or .005 inches. As shown in Fig. 3C, the bottom of the insert 320 is tapered from one side to the other. Figs. 4A-4D show a cutting insert 340 with a body 345 and four sides 341, 342, 343, and 344. As with the cutting inserts described above, the cutting inserts 340 shown from above as rectangular, may be any desired shape. The top surface of the body 345 has four cutting surfaces 351, 352, 353, and 354 each with a plurality of chipbreakers 348 formed therein with ridges 349 therebetween. One particular embodiment of the insert 340 has the following dimensions in inches: a .005 d .188 g .156 j .375 b .125 e .01 h .229 k .063 c .5 f .083 i .302 1 .015 The angular dimension m is about 1.8 degrees and the radiuses in inches are: n .03 o .005 p .015 q .04 * * * Fig. 5 shows cutting inserts 360, 361, and 362 in an array. The cutting insert 360 has four cutting surfaces 371, 372, 373, 374 and a tab receiving recess 375. The cutting insert 361 has three cutting surfaces 381, 382, 383, and 384 each with a chipbreaker indentation; a tab 385; and a tab receiving recess 386. The cutting insert 361 has different depth chip- breakers 387 and 388 in its milling surfaces and all milling surfaces are at different levels. The tab 385 is positioned in the tab receiving recess 375 of the cutting insert 360. The cutting insert 362 has three cutting surfaces 391, 392, 393 each with a chipbreaker indentation and a tab 394 that is positioned in the tab receiving recess 386 of the insert 361. The cutting insert 361 may be omitted from the pattern of Fig. 5. Alternatively, multiple cutting inserts 361 may be used. It is within the scope of this invention to provide a tab on any insert and a tab receiving recess on any cutting insert. It is within the scope, of this invention for the tab to be at any level on the insert (as viewed from the side in Fig. 5); to be on any side of the cutting insert; and for a tab receiving recess to be anywhere on a cutting insert suitable for positioning therein of a tab. Also the extent of the tab (side-to-side in Fig. 5) may be any desired length with a corresponding tab receiving recess. The tab members may extend across the entire width of a cutting insert or only partially thereacross. Any tab may have a chip breaking indentation or part thereof. Fig. 6 shows cutting inserts 376, 377 and 378 in an array. The cutting insert 376 has cutting surfaces 363, 364, and 365 each with a chipbreaker 366. The cutting insert 377 has a tab 367 with a chip- breaker indentation 368; a cutting surface 369 with a chipbreaker indentation 389; a cutting surface 395 with a chipbreaker indentation 396; and a step surface 397 over which a tab is positionable. The cutting insert 378 has a tab 398 that overlies the step surface 397; a cutting surface 399; a chipbreaker 355 on the tab 398 and on the milling surface 399; a cutting surface 356; a cutting surface 357; and chip- breakers 358. Fig. 7 shows (side view) an insert 400, an insert 401, and an insert 402, all according to the present invention. Each insert has two top milling surfaces. The insert 400 has a tapered or canted end 403. The insert 401 has a front end 404 that is angled to correspond to and be positioned under the canted end 403 of the insert 400. The insert 401 has a canted end 405. The insert 402 has a front end 406 that is angled to correspond to and be positioned under the end 405 of the insert 401. Each insert has two top milling surfaces, but it is within the scope of this invention for there to be one, three, four or more such surfaces with or without one or more chipbreakers . Fig. 7B shows cutting inserts 471, 472 and 473 in an array. The cutting insert 471 has a cutting surface 474; a cutting surface 475; a tapered end 476; and a recess 477. The cutting insert 472 has a tab 473 part of which is in the tab recess 477; a tapered end 478; a cutting surface 479; a cutting surface 480; a tapered end 481 and a tab recess 482. The cutting insert 473 has a tab 483 part of which is in the tab recess 482; a tapered end 484; a cutting surface 488; and a milling surface 486. By appropriate sizing of the tab recesses and the tabs, the spacing between the cutting inserts is determined (or abutment of two cutting inserts). Except for the tapered end(s) and/or tab members and recesses, the cutting inserts of Figs. 7A and 7B, in certain aspects, are like that of Figs. 2A-2D. Cutting inserts according to the present invention as in Fig. 8 may have one, three, four or more cutting surfaces with or without one or more chipbreakers. With respect to the cutting inserts of Fig. 7B (and any spaced-apart cutting inserts disclosed herein) tabs and recesses, may be used to achieve desired spacing and matrix material and/or milling matrix material may be emplaced in any space between cutting inserts. Tabs, and/or recesses may be used to achieve proper arrangement, alignment, and orientation (one cutting insert with respect to another as well as various rake angles) of cutting inserts on milling bodies or on milling blades. Cutting inserts disclosed herein may be applied by any known application method in any known combination, pattern, array or arrangement. Figs. 9A and 9B show a cutting insert 420 like the cutting insert 300 described above, but with a tab 421 projecting from one of its sides. The cutting insert 420 with the tab 421 may be used with a cutting insert like the insert 300 (or any cutting insert disclosed herein) to space the cutting insert 420 apart from another insert with the tab 421 abutting the other insert. Alternatively, the tab 421 may be positioned in a corresponding recess of another insert, either with a tight fit or a loose fit, depending on abutment or spacing desired between the cutting inserts. Figs. 9C and 9D show a cutting insert 430 like the cutting insert 300 described above, but with a tab insert recess 431 for receiving a tab like the tab 421 of the insert 420. Fig. 9E shows an array of cutting inserts 420 and 430. It is within the scope of this invention to provide cutting inserts with one or more tabs of any desired shape (half circle, square, rectangular, triangular, half oval, trapezoidal, etc) and cutting inserts with recesses shaped to receive such tabs or part thereof. It is within the scope of this invention to provide a cutting insert with a tab on one, two, three or four sides (or for a non-straight sided cutting insert to provide one or more steps or cutting tabs on a curved surface thereof ) and corresponding cutting inserts with a corresponding recess or recesses. Thus, in one aspect, an array of interlinked cutting inserts is provided, such as the array 450 of Fig. 9A that includes a cutting insert 451 (Fig. 9B) with tabs 452 and 453; a cutting insert 454 (Fig. 9C) with tab recesses 455, 456; a cutting insert 457 (Fig. 9D) with a tab recess 458 and a tab 459; and a cutting insert 460 (Fig. 9E) with a tab 461 and a tab recess 462. A minimum space is shown between cutting inserts in the array 450, but any de- sired spacing may be employed or the cutting inserts (or any pair of cutting inserts or group) may abut each other. In certain embodiments a plurality of cutting inserts are used adjacent each other and it is not desirable for the breaking of one cutting insert to result in the breaking of an adjacent cutting insert. It is within the scope of this invention to use a tab of such a thickness that it provides the desired interlinking and/or insert-to-insert spacing, but is sufficiently weak that the tab breaks in response to force on an adjacent cutting insert without the breaking of the cutting insert with the tab. In other aspects, the tab (instead of or in addition to reduced thickness) may have a weakening groove, cut, or indentation (which may or may not be one or more chipbreakers). For example, and without limitation, the chipbreaker indentation 368 of the tab 367 (Fig. 8) may be of sufficient size to render the step member a "breakaway" member if force applied to the cutting insert 376 is sufficient to break the cutting insert 376. It should be appreciated that whilst the tab can be used to determine the spacing between adjacent cutting inserts the primary function of the tab is to allow adjacent cutting inserts to support one another and inhibit inadvertent dislocation from a given position. For the avoidance of doubt, as used herein the term "cutting" is intended to include "milling".

Claims: CLAIMS 1. A cutting insert for use in a wellbore milling tool, characterised in that said cutting insert is provided with means which will co-operate with another cutting insert to inhibit inadvertent dislocation thereof. 2. A cutting insert as claimed in Claim 1, wherein said means comprises a tab. 3. A cutting insert as claimed in Claim 2, wherein said means comprises an undercut to accommodate a tab. 4. A cutting insert as claimed in Claim 2 or 3, wherein said means comprises a recess positioned to receive a tab. 5. A cutting insert as claimed in any preceding claim, wherein said means comprises a sloping surface. 6. A cutting insert as claimed in Claim 1, including a rectangular base having four sides at least two of which are provided with said means. 7. A cutting insert as claimed in Claim 6, wherein each side is provided with said means. 8. A cutting insert as claimed in any preceding claim, said cutting insert comprising a body having a base which can be mounted on a surface of said wellbore milling tool and a cutting surface bounded by linear boundaries which extend from a first edge of a cutting insert to a second edge thereof, said cutting surface having a plurality of ridges which extend between said linear boundaries, said cutting insert further comprising at least two cutting surfaces, the linear boundaries of which are substantially parallel to one another. 9. A cutting insert as claimed in Claim 8, wherein at least one of said cutting surfaces is at a different distance from the base than the other cutting surface(s) . 10. A cutting insert as claimed in Claim 8 or 9, further comprising a plurality of chipbreaking indentations on each cutting surface. 11. A cutting insert as claimed in Claim 10, wherein said chipbreaking indentations have an oval shape as viewed from above. , 12. A cutting insert as claimed in Claim 10, wherein said plurality of chipbreaking indentations is a patterned array of rows and columns of indentations covering substantially the entire cutting surfaces. 13. A cutting insert as claimed in any of Claims 8 to 12, comprising three cutting surfaces including a first (side) cutting surface, a second (middle) cutting surface, and a third (side) cutting surface with the second (middle) cutting surface disposed between the first (side) cutting surface and the third (side) cutting surface. 14. A cutting insert as claimed in Claim 13, wherein the second (middle) cutting surface projects beyond the first (side) cutting surface and the third (side) cut- ting surface. 15. A cutting insert as claimed in Claim 14, wherein the second (middle) cutting surface projects beyond the first (side) cutting surface and the third (side) cutting surface by a distance between about 0.7mm (.03") and about 2.3mm (.09"). 16. A cutting insert as claimed in Claim 14, wherein the first (side) cutting surface and the third (side) cutting surface project beyond the second (middle) cutting surface. 17. A cutting insert as claimed in Claim 16, wherein the second (middle) cutting surface is between 0.7mm (.03") and 2.3mm (.09") lower than said the first (side) cutting surface and said third (side) cutting surface. 18. A cutting insert as claimed in any of Claims 8 to 17, wherein at least one of the cutting surfaces lies in a first plane at an angle to a second plane in which another of said cutting surfaces is disposed. 19. A cutting insert as claimed in Claim 18, wherein the angle between said first and second planes is great- er than 180° . 20. A cutting insert as claimed in Claim 18, wherein the angle between said first and second planes is less than 180°. 21. A cutting insert as claimed in any of Claims 8 to 20, wherein said base is rectangular. 22. A cutting insert as claimed in Claim 21, wherein said base is square. 23. A cutting insert as claimed in Claim 8, wherein the ridges on one of said cutting surfaces are offset with respect to the ridges on an adjacent cutting surface. 24. A wellbore cutting tool provided with a cutting insert as claimed in any preceding claim. 25. A cutting insert for use in a wellbore milling tool, said cutting insert comprising a body having a base which can be mounted on a surface of said wellbore milling tool and a cutting surface bounded by linear boundaries which extend from a first edge of the cutting insert to a second edge thereof, said cutting surface having a plurality of ridges which extend between said linear boundaries, characterised by two cutting surfaces the linear boundaries of which are substantially parallel to one another. 26. A cutting insert as claimed in Claim 25, wherein one of said cutting surfaces is at a different distance from the base than the other cutting surface(s). 27. A cutting insert for use in a wellbore milling tool, said cutting insert comprising a body having a base which can be mounted on a surface of said wellbore milling tool and a cutting surface bounded by linear boundaries which extend from a first edge of the cutting insert to a second edge thereof, said cutting surface having a plurality of ridges which extend between said linear boundaries, characterised by four cutting surfaces, the linear boundaries of which are substantially parallel to one another. 28. A cutting insert as claimed in ClaiYn 1, wherein at least one of said cutting surfaces is at a different distance from the base than the other cutting surface( s ) . 29. A cutting insert as claimed in any of Claims 25 to 28, further comprising a plurality of chipbreaking indentations on each cutting surface. 30. A cutting insert as claimed in Claim 29, wherein said chipbreaking indentations have an oval shape as viewed from above. 31. A cutting insert as claimed in Claim 29, wherein said plurality of chipbreaking indentations is a patterned array of rows and columns of indentations covering substantially the entire cutting surfaces. 32. A cutting insert as claimed in Claim 26 or 28 or any claim dependent directly or indirectly thereon, wherein one of the cutting surfaces projects beyond another (the other) cutting surface by a distance between about 0.7mm (.03") and about 2.3mm (.09"). 33. A cutting insert as claimed in any of Claims 25 to 32. wherein said base is rectangular. 34. A cutting insert as claimed in Claim 33, wherein said base is square. 35. A wellbore cutting tool provided with a cutting insert as claimed in any of Claims 25 to 34.

Inventors: HUTCHINSON CHRISTOPHER PAUL, HUTCHINSON, CHRISTOPHER, PAUL
Applicants: LUCAS BRIAN RONALD, WEATHERFORD LAMB, LUCAS, BRIAN, RONALD, WEATHERFORD/LAMB, INC.
Application year: 1998
Main classification: E21B29
IPC codes: E21B29