US2152628A - Well bit - Google Patents

Description

A ril 4, 1939. L. A. GAUTHEY ET AL WELL BIT 2 Sheets- Sheet 1 Filed July 23, 1957 April 4, 1939. A. GAUTHEY El AL 2,152,628

WELL BIT f Filed July 23, 1937. 2 Sheets-Sheet 2 and IVQLM/Y C Mme-A ma Patented Apr. 4, 1939 UNITED STATES PATENT OFF-ICE WELL BIT Application July 23, 1937, Serial No. 155,240 I 11 Claims.

This invention relates to well drilling tools and relates more particularly to a well bit for use in the rotary method of deep well drilling. A general object of this invention is to provide a rotary well drilling bit that is very rapid in its penetration of the earth formation and that is inexpensive to manufacture and to recondition after use.

The roller well bits now in general use embody pairs or pluralities of broad roller cutters. Such roller bits or rock bits have certain limitations and undesirable characteristics. For example, a roller bit is not successful in sticky or plastic earth formations or in mixed or varied earth formations, due to its tendency to track without cutting and due to its tendency to become balled up due to accumulations of mud and cuttings. Roller bits are also expensive to operate because it is necessary to completely replace the roller cutters, the cutter bearings and the cutter supporting shafts after each run.

Another object of this invention is to provide a rotary well bit that is efficient and very rapid in its cutting operation in hard earth formations and in mixed or varied earth formations.

Another object of this invention is to provide a rotary well drilling bit that embodies a single rotatable cutter and, therefore, is very inexpensive to manufacture and to recondition after use.

Another object of this invention is to provide a rotary well drilling bit that embodies a single toothed rotatable cutter of substantial diameter and of short axial extent or thickness.

r Another object of this invention is to provide a rotary well drilling bit of the character mentioned that embodies spaced drag type blades engaging the earth formation to balance the rotatable cutter and to maintain it in proper cooperation with the earth formation, and to 40 bear on the side wall of the well to stabilize the bit.

Another object of this invention is to provide a rotary well drilling bit of the character men- 4 tioned in which the rotatable cutter is formed and mounted so that its teeth have a very eiiicient gouging-engagement with the earth formation as distinguished from the crushing action of the teeth of typical roller cutters.

A further object of this invention is to provide a rotary well bit of the character mentioned embodying an improved system of fluid passages and discharge ports for effecting the full flushing of the rotatable cutter and the blades and the agitation of the cuttings in the well bore without injuring the cutter or the blades by the erosive action of the discharged fluid under pressure.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form 5 and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of the improved bit provided by this invention. Fig. 2 is a bottom view of the bit. Fig. 3 is an enlarged, fragmentary side elevation of the bit illustrating one side or face of the rotatable cutter. Fig. 4 is a horizontal detailed sectional view taken as indi- :cated by line 4-4 on Fig. 3, and Fig. 5 is a reduced diagrammatic view illustrating the manner in which the rotatable cutter and the blades engage the earth formation.

The rotary well bit provided by this invention includes, generally, a shank or body It having 20 a depending leg II, a cutter I 2 supported on the leg I l for rotation about a transverse axis and spaced cutting and stabilizing blades l3 and I l projecting from the lower end of the body II].

The shank or body ID of the bit is intended to be connected with the lower end of a rotary well drilling string. The body l0 may be a simple, integral or one-piece member as illustrated in the drawings. Means is provided at the upper end of the body II] for connecting it with the well drilling string. In the particular case illustrated a tapered screw-threaded socket I5 is provided in the upper end of the body ID to facilitate its connection with the string. The shank or body It ispreferably cylindrical and its lower end is generally horizontal and may be slightly convex. The leg ll projects downwardly or vertically from the lower end of the body II] and is preferably integral with the body. In accordance with the invention the leg II is offset from the vertical or central axis of the body Ill. The leg II preferably projects outwardly slightly at the lower end of the body III and its inner and outer sides I6 and I"! are substantially vertical. The inner side I5 of the leg II is flat and tangent to a circle concentric with the vertical axis of the body Iii. The outer side I! of the leg I I may be suitably cylindrically rounded and the lower end of the leg may be rounded or convexed.

The cutter I2 is rotatably supported at the inner side I6 of the leg I I for rotation about a substantially horizontal or transverse axis to act on the earth formation at the bottom of the well bore and the formation at the side wall of the well bore adjacent the bottom. The cutter 12 has a diameter that is great relative to its thickness or axial length, and, therefore, may be termed a semi-disc cutter. The periphery of the cutter I2 is provided with cutting teeth. It is preferred to provide two rows of circumferentially spaced teeth [8 on the periphery of the cutter l2 and relate the teeth It so that the teeth of one row are offset with relation to the teeth of the other row. The cutting teeth l8 are preferably large and deep and the two rows of teeth are separated by a circumferential groove I9. While the teeth l8 may be straight and axial it is preferred to pitch or spiral the teeth as illustrated in the drawings. The crests or active edges 20 of the teeth l8 are curved to conform to the wall of the well bore as will be subsequently described. The end or side 22 of the cutter l2 which opposes the inner side it of the leg H is preferably flat. The opposite side 23 of the cutter I2 is concaved or dished so that the teeth l8 at the leadingside of the cutter may more effectively dig or bite into the earth formation.

The means for rotatably supporting or mounting the cutter l 2 on the leg l l is preferably a'simpie anti-friction means. The cutter I2 is provided with a central longitudinal opening 24 and a recess 25 in the side 23 around the opening 24. An anti-friction roller bearing 26 is provided in the opening 2 and a pin 2'! passes through the bearing 26 and is supported by the'legv l l whereby the bearing 26 rotatably supports the cutter l2 on the pin. The bearing 26 may be of conventional design and construction and the pin 21 is suit ably hardened. A head 28 is provided on one end of the pin 27 and is received in the recess 25. The opposite end portion of the pin 21 is' received in an opening 39 in the leg ll. Welding 3| may rigidly fix the pin 2! in the opening 30. A hardened thrust washer 32 is provided on the pin 2? to transmit end thrusts from the side 22 of the cutter [2 to the inner side I6 of the leg H. The thrust washer 32 may be partially recessed in the cutter l2 and the leg H. The opening 30 receiving the cutter supporting pin 27 is horizontal and is located so that the cutter l2 supported by the pin projects downwardly beyond the lower end of the leg I I and laterally or transversely beyond the forward edge of the leg I! relative to the direction of rotation of the well bit.

The location of the rotatable cutter I2 is "an important feature of the invention. The axis of rotation of the cutter I2 is substantially horizontal or transverse of the vertical axis of the bit body It! and is tangent to a circle concentric with said axis. Further, the cutter I2 is offset from or spaced at one side of the vertical axis of the bit body ill in the direction of the leg H so that its side 23 is adjacent but spaced from said axis. As illustrated in Figs. 2 and 4 of the drawings where the arrow X indicates the direction of ro tation of the bit the cutter l2 projects forwardly beyond the leading edge of the leg ll relative to the direction of rotation of the bit, so that the teeth It at the leading portion of the cutter l2 cut or gouge into the formation at the side wall of the well bore adjacent the bottom of the bore. The olfset cutter l2 also projects downwardly beyond the lower end of the leg H and; of course, its teeth l8 act on the bottom of the well bore. As best illustrated in Figs. 3 and 5 of the: drawings the-rotatable cutter E2 of large diameter located as described above acts on the bottom of the well bore and the side wall of the well bore adjacent its bottom to give the wall the dished or concaved configuration shown at Y in Fig. 5. The engagement of the cutter teeth 58 with the earth formation causes the cutter l2 to rotate on its axis in the direction indicated by the arrow Z. The location of the cutter l2, the bodily rota-, tion of the cutter with the bit body ill, the independent rotation of the cutter l2 on its own axis and the shape of the teeth 18 cause the teeth to successively shear and gouge into the earth formation to be particularly effective and rapid in their cutting action. The teeth It of the two rows of teeth are spiralled in such a manner that they are particularly effective in cutting through the earth formation and the staggered relation of the teeth gives the cutter ii a maximum cutting action with a substantial spacing between the adjacent teeth of the rows. The cutter i2 is of substantial diameter relative to the diameter of the well bore.

The blades 83 and Hi are the dragging or scraping cutting parts of the tool and are rigid with the bit body it. In the preferred construction the blades l3 and M are integral with the body I 6.]. The two blades 63 and I 4 project downwardly from the lower end of the body and are substantially vertical. The blades l3 and M are flat plate-like parts having parallel opposite sides. In accordance with the invention the blades I 3 and M are located at the opposite side of the axis of rotation of the body it) from the cutter l2 and are in substantially V-relation, that is, they converge inwardly toward the central axis of the bit to have their inner portions join. The blades is and It are proportioned to project laterally or horizontally beyond the periphery of the body ill and their outer edges are adapted toact on the wall of the well bore. Theblades l3 and M have upper active edges M and 35, respectively, that are straight and substantially vertical and lower outer edges 36 and 37, respectively, that are curved downwardly and inwardly relative to the axis of rotation of the tool. The lower ends of the blades l3 and M are preferably inclined upwardly and inwardly to more effectively act on the inner portion of the well bore. The active edges of the blades l3 and i4 may be bevelled, although it is preferred to make the straight edge portions 34 and 35'comparatively wide to have ex tensive bearing cooperation with the side wall of the well.

The parts are related so that the blade I3 acts on the earth formation substantially diametrically opposite the point or line of engage-- ment of the cutter 92 with the formation. Figs. 2 and 4 of the drawings best illustrate this relationship between the blade l3 and the cutter E2. The blade M is spaced between the leading portion of the cutter i2 and the blade is. With the relationship described above the blades l3 and M cooperate with the earth formation to main.- tain the rotatable cutter l2 in cutting cooperation with the earth formation. The lower'curved edges 36 and 3! of the blades 53 and Id have cutting cooperation with the dished wall portion Y of the well bore to assist in cutting away the formation and to scrape away the formation. loosened by the teeth 88 of the cutter H2. The upper edge portions 34 and 35 of the blades 13 and I4 bear on the cylindrical side wall of the well bore to dependably stabilize thebit. A relatively large horizontal opening 38 is provided in the connected inner portions of the joined blades l3 and It to facilitate the assembly of the pin. 2'! and to assist in preventing the mud and cuttings from accumulating on the bit. The opening 38 is sufficiently large in diameter to pass the pin 21 and its head 28 whereby the pin may be inserted through the bearing 26 and into the opening 30.

The invention provides a novel and particularly effective system of ports for flushing the rotatable cutter I2 and the blades I3 and 14. The lower portion of the socket 15 receives the circulation fluid from the drilling string and forms a fluid distributing chamber. A plurality of fluid discharge ports 40 is provided in the body Ill to efiect the flushing of the rotatable cutter l2. The ports 40 extend downwardly through the body I!) from the lower end of the socket 55 to the lower end of the body. The ports 40 are preferably aligned or arranged in a row and discharge downwardly at the side 23 of the cutter I2. The ports 40 are transversely elongated to discharge relatively broad streams of fluid across the side 23 of the cutter 12. In the arrangement illustrated there are three aligned ports 40 positioned so that two of the ports discharge downwardly across the face 23 of the upwardly moving trailing portion of the cutter l2. The outermost ports 49 of the row or series of ports are inclined downwardly and outwardly, as best'illustrated in Fig. 3 of the drawings. A port 4| is provided in the body Ill and extends downwardly from the lower end of the socket 15 to the lower end of the body to discharge a stream of fluid against the teeth l8 of the cutter I2. The port 4| is elongate in transverse cross section and has its major transverse axis axial relative to the cutter 12 to discharge a broad stream of fluid that impinges against both rows of teeth I8. A port 42 extends downwardly from the lower end of the socket to the lower end of the body and is positioned to discharge a stream of fluid downwardly into the groove I9 between the rows of cutters It to flush mud and cuttings from the groove. The port 42 may be round or cylindrical and may discharge substantially directly downwardly into the groove I9.

The means for flushing the blade I3 comprises a fluid discharge port 43. The port 43 extends downwardly and outwardly from the lower end of the socket I5 and passes through a projection or reinforcement 44 on the upper part of the leading face of the blade l3. The port 43 is elongate in transverse cross section and has its major transverse axis substantially parallel with the leading face of the blade l3 to discharge a broad stream f circulation of fluid downwardly across the leading face of the blade. ing the blade I4 comprises a fluid discharge port 45 extending downwardly through the body Hi from the socket IE to the lower end of the body. The discharge end of the port 45 is immediately in front of the leading side of the blade 64 relative to the direction of rotation of the bit. The port 45 is preferably elongate in transverse cross section and has its major transverse axis substantially parallel with the leading face of the blade E4 to discharge a broad stream of circulation fluid downwardly and outwardly across the leading face of the blade. The fluid discharged from the ports 43 and 45 effectively clears the blades l3 and I4, respectively, of cuttings and mud.

It is believed that the operation of the bit provided by this invention will be readily understood from the foregoing detailed description. In operation the bit body I0 is connected with the lower end of a rotary well drilling string which is rotated and fed downwardly in the usual manner. As described above, the teeth l8 of the cutter H The means for flushact on the wall of the well bore at the bottom of the bore and at the side of the bore adjacent the bottom to give the bore the dished or concaved wall Y shown in Fig. 5. The location and. shape of the cutter l2 are such that the teeth l8 have a combined scraping and gouging engage-' ment with the formation which is particularly rapid in cutting away the formation. The cutter l2 turns about its own axis at a relatively slow rate so that the teeth l8 successively come into cutting engagement with the earth formation. The spaced radiating blades i3 and'l4 engage the wall of the well bore to maintain the cutter l2 in proper engagement with the earth formation and to assist in the cutting action. Further, the broad substantially vertical upper faces 34 and 35 of the blades !3 and M, respectively, have bearing engagement with the'side wall of the bore to stabilize the bit. The lower curved surfaces or edges 36 and 31 of the blades l3 and 14, respectively, are shaped to assist in cutting the earth formation at the dished portion Y of the well.

The circulation fluid is pumped downwardly through the drilling string in the usual manner to J discharge from the ports of the body I0. The

fluid discharged from the ports 4'! and 42 flushes the cutters E2 to prevent mud and cuttings from accumulating on the cutter. The fluid discharged from the ports 4!! flushes across the-face 23 of the cutter l2 to clear the same. Further, the fluid discharging from the ports 4!! or certain of them discharges outwardly through the opening 38 to remove the mud and cuttings fromthe central portion of the bit and the opening 38 forms an effective outlet for the mud and cuttings. The ports 43 and 45 discharge broad streams of fluid which fully flush the active forward faces of the blades l3 and I4.

Having described only a typical preferred form and application of our invention, we do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described our invention, we claim:

1. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a disc-like cutter having spaced rows of circumferentially spaced teeth on its periphery, the teeth of one row being offset from the teeth of the adjacentrow, means supporting the cutter at the lower end of the body to rotate about a substantially horizontal axis where it projects downwardly and laterally at one side of the body, blades projecting downwardly and laterally from the body at the other side of the body, and separate means for flushing the cutter and blades.

2. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a disc-like cutter having spaced rows of circumferentially spaced teeth on its periphery, the teeth of one row being offset from the teeth of the adjacent row, means supporting the cutter at the lower end of the body to rotate about a substantially horizontal axis where it projects downwardly and laterally at one side of the body, said means including a leg depending from the lower end of the body at one side of the vertical axis of the body, the leg having a substantially horizontal opening, and a pin secured in the opening projecting from the inner side of the leg and rotatably supporting the cut-- ter, and a pair of outwardly radiating blades projecting downwardly and laterally at the other side of the body, the blades having an opening aligned with the first mentioned opening and adapted to pass the pin,

3. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a disc-like cutter having spaced rows of circumferentially spaced teeth on its periphery, the teeth of one row being offset fromthe teeth of the adjacent row, means supporting the cutter at the lower end of the body to rotate about a substantially horizontal axis where it projects downwardly and laterally at one side of the body, blades projecting downwardly and laterally from the body at the other side of the body, and separate means for flushing the cutter and blades, the last named means comprising a row of ports in the body discharging downwardly across the forward face of the cutter, a port in the body discharging downwardly between the rows of teeth and a port in the body discharging downwardly across the forward face of each blade.

4. A rotary well drilling bit comprising a body to be rotated in the well, a rotatable cutter, means supporting the cutter at the lower end of the body for rotation about an axis substantially transverse of the axis of rotation of the body and tangent to a circle concentric with the axis of rotation of the body to have the cutter project downwardly and laterally beyond the lower end of the body so that the cutter acts on the bottom wall of the well and the side wall of the well, and a blade rigid with the body projecting downwardly and laterally beyond the lower end of the body to engage the bottom wall of the well and to engage the side wall of the well at a point substantially opposite the point of engagement of. the said cutter with the side wall to maintain the cutter in active engagement with the side Wall of the well.

5. A rotary well drilling bit comprislng a body to be rotated in the well, a rotatable cutter, means supporting the cutter at the lower end of the body for rotation about an axis substantially transverse of the axis of rotation of the body and tangent to a circle concentric with the axis of rotation of the body so that the cutter projects downwardly and laterally beyond the lower end of the body to act on the bottom wall of the well and to act on the side wall of the well at one side of the bit, and two laterally diverging cutting blades rigid with the body and projecting downwardly and laterally beyond the lower end of the body to act on the bottom and side walls of the well and maintain the cutter in active engagement with the well Wall, one blade being positioned to act on the side wall of the well at a point substantially opposite the point of engagement of the cutter with the side wall of the well.

6. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a disc-like cutter, means supporting the cutter at the lower end of the body for rotation about an axis substantially transverse of and laterally offset from the axis of rotation of the body so that the cutter projects downwardly beyond the lower end of the body and laterally beyond one side of the body, and laterally diverging drag type blades rigidly secured to the body and projecting beyond its lower end and projecting laterally beyond the other side of the body.

'7. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a depending leg on the lower end of the body, a substantially disc-shaped cutter having peripheral cutting teeth, means supporting the cutter on the body leg for rotation about a substantially horizontal axis offset from the central vertical axis of the body so that the cutter projects downwardly and laterally from one side of the body to have its teeth act on the earth formation to provide the bottom of the well with a concaved outer portion, and a cutting blade rigid with the body and projecting downwardly and laterally from the lower end of the body at the other side of the body, the blade being shaped to conform to said bottom portion of the well and to bear on the side wall of the well.

8. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a substantially discshaped cutter having peripheral cutting teeth, means supporting the cutter on the body for rotation about a substantially horizontal axis where it projects downwardly and laterally from one side of the body so that its teeth act on the side wall and the bottom wall of the well tomake the outer portion of the well bottom concave, and two laterally diverging cutting blades projecting downwardly and laterally from the body, the blades having active edges curved to conform to the concave'portion of the well wall, one blade being positioned to act on the side wall of the well at a point substantially opposite the point of engagement of the cutter with the side wall, the other blade being spaced between the cutter and the first mentioned blade.

9. A bit for use on a rotary well drilling string comprising a body to be connected with the string to be rotated thereby, a substantially discshaped cutter having peripheral cutting teeth, means supporting the cutter on the body for rotation about a substantially horizontal axis offset from the vertical axis of the body where it projects downwardly and laterally from one side of the body so that its teeth act on the side wall andthe bottom wall of the well to make the outer portion of the well bottom concave, and

blades rigid with the body projecting downwardly and outwardly from the other side of the body, the blades having broad upper edges bearing on the side wall of the well and lower active edges curved to conform to the concave portion of the well wall.

10. A rotary well drilling bit comprising a body to be rotated in the well, a rotatable cutter,

means supporting the cutter at the lower end of the body for rotation about an axis substantially transverse of the axis of rotation of the body so that the cutter projects laterally beyond the body to act on the earth formation at the bottom and at one side of the Well bore, a cutting blade rigid with the body projecting downwardly and laterally from the body and acting on the formation at the bottom and the other side of the well bore, and a cutting blade rigid with the body spaced between the leading part of the cutter and the trailing side of the first named blade relative to the direction of rotation of the body and projecting downwardly and outwardly from the body to act on the bottom and side wall of the well.

11. A rotary well drilling bit comprising a body, a single cutter mounted on the lower end of the body at one side of its vertical axis to rotate about a substantially horizontal axis and to project downwardly and outwardly from the body to make a dished annular cut in the bottom of the well, and.- laterally diverging cutting blades rigid with the body and projecting downwardly and laterally from the lower end of the body at the other side of its vertical axis to assist the rotatable cutter in making said out and to maintain the cutter in position to cut the bore to gauge.

LOUIS A. GAU'I'HEY. WILLIAM C. KUYKENDALL.

Images