US2056498A - Reamer - Google Patents

Description

I OcL'G, 1936.

J. c. WRIGHT REAMER Filed May 19, 1935 55a 6. h r-lghf Afforneg Patented Oct. 6, 1936 ATENT OFFI REAMER Jesse C. Wright, Los Angeles, Calif., assignor to Globe Oil Tools Company, Los Nietos, Califi, a corporation of California Application May 19, 1933, Serial No. 671,875 7 Claims. (01. 255-73) This invention relates to a well drilling tool and relates more particularly to a well reamer. It is a general object of this invention to provide a simple, practical and effective well reamer having 1 novel and eiilcient replaceable cutters.

Another object of the invention is to provide a reamer for use in the rotary method of well drilling including rotatable cutters having particularly effective cutting parts.

Another object of the invention is to provide cutter for use on a well reamer having helical or spiralled cutting parts or teeth.

Another object of the invention is to provide a Well reamer havingcutters rotatably mounted in a manner so that they may have heavy or deep cutting parts.

Another object of the invention is to provide a simple and effective means for removably or replaceably mounting the rotatable cutters on a well reamer. I

It is another object of the invention to provide a well reamer in which the pins carrying the rotatable cutters are not subjected to the wear caused by rotation of thecutters and therefore do not have to be replaced with the cutters. 1

Another object of the inventionis to provide a reamer of the charactergmentionedg in whichreadily replaceable bearings .orbushings are provided on'the cutter carrying pins to 'rot'atably carry the opposite end portions of the cutters. In accordance with-the present invention, the replaceable bushings on the pins within the end portions of the cutters and the replaceable thrust washers at the ends of the cutters receive all the 'wear caused by th'erotation of the cutters so that the pins are prevented from becoming worn, and thebushing, in being provided in the end portions of the cutters, permit the provision of heavy or deep cutting teeth on the intermediate or major portions of the cutters.

' A further object of the invention'is to provide a well reamer of the character mentioned involving simple and'eifective means for removably locking the cutter carrying pins against rotation and longitudinal movement. Other objects and features of the invention will be best and fully understood from the following detailed description of a typical form and application of the invention, throughout which description, reference will be had to the accompanying drawing, in which:

Fig. 1 is a side elevation of the reamer pro-- vided by the present invention with a portion broken away to illustrate the manner of locking the cutter carrying pins against movement. Fig.

2 is a transverse detailed sectional View taken as indicated by line 2-2 on Fig. 1. Fig. 3 is an en'- larged fragmentary detailed sectional View illustrating one of the cutters and its mounting means, and Figs. 4 and 5 are fragmentary transverse detailed sectionalviews taken as indicated by lines 4% and 55 respectively, on Fig. 3.

The well reamer provided by the present invention includes, generally, a body ll], rotatable cutters l, and means l2 for detachably mounting the cutters H on the body.

The body IU of the reamer is an elongate member adapted to be connected in a well drilling string. The opposite end portions l3 of the body It! may be cylindrical or round in cross section. Means is provided at the opposite ends of the body In for facilitating its connection in thedrill-' ing string. In the particular embodiment of the invention illustrated in the drawing, a tapered pin [4 is'provided 'on the upper end of the body l0 and is adapted to be threaded into the socket of a drill collar and a socket I5 is provided in the lower end of the body for receiving the threaded pin of the drilling bit. Itis to be understood that if the reamer is to be arranged in the drilling string above the drill collar, a socket may be provided in the upper end of the body H) to receive a pin on a part of the drilling string and a pin may be provided in the lower end of the body to thread into the socket in the upper end of the drill collar. Spaced grooves are provided in the upper portion l3 of the body to form annular wickers or ribs for engagement by a fishing tool such as a slip socket, or the like.

The cutter carrying portion ll of the body I0 is of enlarged cross section and is substantially triangular in cross section as illustrated in Fig. 2 of the drawing. The sides or faces is of the triangular cutter carrying portion H are preferably flat and vertical as illustrated. The opposite ends of the triangular portion I! are bevelled to join the cylindrical end parts E3. The apices or corners of the cuttercarrying portion I l are preferably rounded. In accordance with the invention, vertical or longitudinal recesses l9 are provided in the corners of the triangular body portion ll. The recesses I!) are provided to carry or hold the cutters H and their inner walls are concaved as clearly illustrated in Fig. 2 of the drawing. The recesses I!) are spaced be-'- tween the opposite ends of the triangular body portion H and their end walls 2!! are normal to the longitudinal axis of the body.

The cutters II are rotatably mounted in the recesses I 9 by the means l2 and their cutting parts project from the open outer ends of the recesses to engage the formation at the wall of the well bore. The cutters II are elongate and of round cross section, and are slightly shorter than the recesses IS. The opposite ends of the cutters l I are flat and normal to the longitudinal axes of the cutters. Each of the cutters H has a central longitudinal opening 22 extending completely through it from one end to the other. The cutters ll rotate on vertical axes and their peripheral parts act on the formation at the wall of the well bore. It is a feature of the present invention that the cutters II are provided with particularly effective cutting parts 24.

The cutting parts 24 extend around the cutters II and are spiralled or helical. In the form of the invention illustrated in the drawing, there is a single continuous helical cutting part 24 on each cutter H, it being apparent that there may be two or more such parts on each cutter, and that the cutting parts may be broken or interrupted if found desirable. The cutting parts 24 resemble coarse V-threads, being substantially V-shaped in cross section. In accordance with the invention, the teeth or cutting parts 24 are comparatively heavy or deep and have sharp cutting edges 25. The lower end portions 26 of the cutters H are frustro-conical and are provided with cutting parts or teeth 21. There is a circumferential series of spaced teeth 21 on each cutter II. The cutting teeth 21 are comparatively thin or shallow, and in the particular embodiment of the invention illustrated in the drawing, extend longitudinally of the cutters II. The spiralled or helical cutting parts 24 are preferably of considerable length and may extend from the tapered lower portions 21 of the cutters to the upper ends of the cutters.

During operation of the reamer the drilling string is rotated in the well and the cutting parts 24 engage the formation at the side wall of the well bore to cut threads in the formation. As the downward movement or feed of the drilling string is comparatively slow, the spiralled cutting parts 24 of the cutters ll shear off the threads as they are formed in the formation and thus enlarge the bore. The threading engagement of the cutting parts 24 with the formation continuously urges the reamer, and parts connected therewith, downwardly and thus provides a downward feed for the drilling tool. The cutters II, in engaging the formation at three circumferentially spaced points, stabilize the lower end portion of the drilling string and the bit connected therewith and the threading or feeding action of the spiralled cutting parts 24 acts to further stabilize or steady the reamer and drilling tool.

The means l2 for removably mounting the rotatable cutters II in the recesses [9 includes a removable pin 30 extending longitudinally through the opening 22 of each cutter II. The pins 30 project or extend from the opposite ends of the cutters l I and have their lower ends seated in sockets 3| in the triangular portion I1 of the body. The upper end parts 32 of the pins 30 are enlarged and are carried in longitudinal openings 33 extending downwardly from the upper end of the portion l1 to the recesses I9. In accordance with the invention, the pins 30 extend through the cutter openings 22 with suitable clearance. The invention provides simple and eifective means for holding the cutter carrying pins 30 against rotation and longitudinal movement. Horizontal or transverse openings 34 are provided in the body to intersect the outer edge portions of the openings 33. Screws 35 extend through the transverse openings 34 and cooperate with notches 36 in the head portions 32 of the pins to positively hold the pins against rotation and longitudinal movement. The heads of the screws 35 are threaded into the leading or forward ends of the transverse openings 34 relative to the direction of rotation of the reamer. The screw heads are countersunk in the transverse openings 34 and cuttings and mud pack in the openings to dependably lock the screws 35 in place.

Renewable or replaceable wear-taking bushings are provided on the pins 36 for rotatably carrying the cutters II. A bushing 38 is provided on each pin 36 to rotatably carry the lower end portion of a cutter II. The comparatively shallow teeth 21 of the tapering lower end portions 26 of the cutters allow the provision of comparatively deep annular recesses or enlargements 39 in the lower portions of the cutter openings 22 to hold the bushings 33. Due to this relationship between the parts, the bushings 38 may be comparatively large in diameter to present substantial wear receiving surfaces. Reduced lower end portions 40 are provided on the bushings 39 and are received in sockets 4| at the lower walls of the recesses l9. Annular flanges 42 are provided on the bushings 38 and project outwardly between the lower ends of the cutters II and the lower walls 30 of the recesses 19. The flanges 42 receive the downward thrusts from the cutters H and effectively space the lower ends of the cutters from the lower walls of the recesses. Novel means are provided for holding the bushings 38 against rotation. A flat or straight face 43 is provided on the flange 42 of each bushing to cooperate with a correspondingly shaped face 44 on the body to hold the bushings against turning.

Removable or replaceable bushings 45 are provided on pins 30 for carrying the upper end portions of the cutters II. The bushings 45 are pressed or otherwise fixed on the pins 30 at the lower ends of the pin enlargements 32. Enlargements 46 are provided in the upper portions of the cutter openings 22 to receive or hold the bushings 45. The bushings 45 are comparatively long and therefore present substantial wear receiving surfaces. Thrust washers 41 are provided between the upper ends of the cutters II and the upper walls 30 of the recesses l9. Straight or flat faces 48 are provided on the inner sides of the thrust washers 41 for engaging similar faces 49 on the body to hold the washers against turning. The thrust washers 41 surround the enlarged parts 32 of the pins 30 as clearly illustrated in Fig. 3 of the drawing.

In assembling a cutter on the body, the assembly of the cutter I l and a bushing 38 is positioned in a recess l9 so that the opening 22 of the cutter is in longitudinal alignment with the openings 3| and 33. In practice, the end clearance of the cutter with the upper wall of the recess is sufficient to permit the proper arrangement of the end part 40 of the bushing in the socket 4 I. The thrust washer 41 may be easily arranged on the upper end of the cutter with its fiat face against the shoulder 49. The pin 30 may then be passed downwardly through the opening 33 and through the cutter opening 22 and then looked in position by the screw 35. The bushing 45 is carried by the pin and is proportioned so that it readily passes through the opening 33. Openings 50 may be provided in the body to extend from the lower end of the portion '1 to the sockets 3| to permit the pins 3'il'to be loosened and driven out of position after removal of the screws 35.

The reamer includes means for handling the circulation fluid and for Washing or flushing the cutters I I. A central longitudinal fluid passage 60 extends through the body I'll from the upper end of the pin M to the socket I5. Downwardly and outwardly inclined outlet or discharge openings 6i extend from the central passage 60 to the inner walls of the recesses I9. The discharge openings GI are preferably substantially tangential to the rear surfaces of the cutters =I I relative to the direction of rotation of the reamer. Flow beans or nozzles 62 are provided in the outer ends of the discharge openings 6 I. The nozzle 62 may be threaded into openings '6 I or may be otherwise removably attached to the body. The openings in the nozzles 62 are considerably smaller in capacity than the openings 6| so that the velocity of the fluid discharging through them is increased to provide for the eifec tive flushing of the cutting parts of the cutters II. Further, the restricted openings in the nozzles 62 reduce the quantity of fluid discharged from the openings GI and cause the nozzles to receive the wear or cutting action due to the discharge of the fluid.

In operation, the drilling string in which the reamer is connected is rotated and the cutting parts 24 and 27 of the cutters II act on the formation at the side walls of the well bore. The spiralled cutting parts 24 cutcircumferential grooves or threads in. the formation, and as the downward feed of the reamer is usually comparatively slow, they shear these threads way from the formation as the tool is rotated. The engagement of the spiralled cutting parts 24 with the formation acts to urge or feed the reamer and drilling tool downwardly and steadies the action of the tools. The cutters I I are particularly effective in their cutting action and in being circumferentially spaced, provide for the smooth operation of the tools. All of the wear caused by rotation of the cutters I I is received by the bushings 38 and 45 and the thrust washer 41. As these wear-taking parts are readily replaceable, the tool is economical to operate. The cutter carrying pins 30 are not subjected to any wear, and therefore do not have to be replaced together with the cutters or the bushings. The provision of the comparatively shallow cutting parts 27 on the tapered lower ends of the cutters permits comparatively heavy bushings 38 to be employed to support the lower ends of the cutters. As the bushings 38 and 45 rotatably support the end portions of the cutters, the cutters may be provided with heavy or deep cutting parts 24. The cutters and wear-taking bushings and washers may be easily and quickly replaced. To remove a cutter I I, the screw 35 is first removed and the pin 3!] is then driven out through the opening 33. The upper bushing 45 is removable together with the pin. The cutter I I and the lower bushing 38 may then be easily lifted out of the recesses I9. In mounting the replacement cutter, the same pin 30 may be employed. The cutter carrying pins 30 are dependably locked in position by the screws 35 which hold the pins against turning and longitudinal movement. The lock screws 35 are dependably set or retained in posi tion by the accumulations of mud etc., in the forward ends of the openings 34 which cover the heads of the screws. The circulation fluid under pressure discharging from the nozzle 62 effectively flushes the cutting parts of the cutters: The reamer provided by the present invention is simple and inexpensive of manufacture and may be readily provided with replacement cutters and wear-taking bushings and washers.

Having described onlya typical form and application, I do not Wish to be restricted or limited to the specific form or application herein set forth, but wish to reserve to myself any modifications or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A well reamer including, a body having a recess, a cutter having a longitudinal opening, and means for rotatably mounting the cutter in the recess, said means including a removable pin extending through the recess and passing through said opening in the cutter, and replaceable bushings on the pin rotatably carrying the opposite end portions of the cutter, the bores of the bushings being of less diameter than said opening whereby the bushings space the wall of said opening out of frictional contact with the 2. A well reamer including, a body having a recess, a cutter having a longitudinal opening, said opening having an enlarged portion at each of its ends, a removable pin carried by the body and extending through the cutter opening with clearance, and replaceable bushings on the pin received by said enlargements of the cutter opening and rotatably carrying the cutter, the bores of the bushings being of less diameter than the cutter opening whereby the bushings prevent frictional contact of the cutter with the pin.

3. A well reamer including, a body having a recess, a cutter having a longitudinal opening, said opening having an enlarged portion at its lower end, and means for rotatably mounting the cutter in the recess, said means including a removable pin carried by the body and freely passing through the opening in the cutter to be out of contact with the cutter, a replaceable bushing on the pin fitting said enlargement of the opening to rotatably carry the lower portion of the cutter, a replaceable bushing on the pin rotatably carrying the upper portion of the cutter, the bores of the bushings being of less diameter than the said opening whereby the bushings prevent frictional contact of the cutter with the pin, and. a thrust washer between the upper end of the cutter and the upper wall of the recess.

4. A well reamer including, a body having a recess, a cutter having a longitudinal opening, said opening having an enlarged portion at its lower end, and means for rotatably mounting the cutter in the recess, said means including a removable pin carried by the body and freely passing through the opening in the cutter without cooperating with its wall, a replaceable bushing on the pin fitting said enlargement of the opening to rotatably carry the lower portion of the cutter, a replaceable bushing on the pin rotat ably carrying the upper portion of the cutter, the bushings carrying the cutter so that the wall of the cutter opening is spaced from the pin, and a thrust washer between the upper end of the cutter and the upper wall of the recess. said washer having a flat peripheral face cooperating with a corresponding face on the body whereby it is held against rotation.

5. A well reamer including, a body having a recess, a cutter having a longitudinal opening, said opening having enlarged portions at the upper and lower ends of the cutter, and means for rotatably mounting the cutter in the recess, said means including a removable pin carried by the body and passing through the opening in the cutter, replaceable bushings fitting said enlargements of the opening and cooperating with the pin to rotatably carry the upper and lower portions of the cutter, the pin passing bores of the bushings being of less diameter than the said opening whereby the bushings hold the wall of said opening out of frictional contact with the pin, and means for holding the bushings against rotation.

6. In a well reamer, a body having an external recess, a cutter having a frusto-conical lower portion, there being a longitudinal opening in the cutter having an enlargement in the lower portion of the cutter, a removable pin carried by the body andextending through the opening in the cutter with suitable clearance, a replaceable bushing on the pin received in the enlargement of the cutter opening, the bore of the bushing being of less diameter than said opening whereby the bushing prevents frictional contact of the wall of said opening with the pin, and cutting parts on the frusto-conical portion of the cutter, the cutting parts being comparatively shallow whereby said enlargement and bushing may be of large diameter.

'7. A well reamer including a body having an external recess and sockets in the opposite end walls of the recess, a cutter having a longitudinal opening and a socket at the upper end of the opening, a pin passing through said opening without contacting its wall and having its lower end carried in one of the first mentioned sockets, replaceable means on the pin rotatably supporting the lower end of the cutter, an enlargement on the pin carried in the other of the first mentioned sockets and presenting a downwardly facing shoulder, and a replaceable bushing carried in said socket of the cutter engaging the pin to rotatably support the upper end of the cutter and bearing upwardly against said shoulder.

JESSE C. WRIGHT.

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