US2197991A - Tool for straightening well bores - Google Patents

Description

Apnl 23, 1940.

J. c. WRIGHT TOOL FOR STRAIGHTENING WELL BORES 4 3 2 www 3 4 1`\ Y Y.

2 Sheets-She APHl 23 1940 J. c. WRIGHT TOOL FOR `STRIGII'I'IENINGP WELL BORES 2 Sheets-Sheet 2 File; Oct @f3 that Patented Apr. 23, 1940 PATlazlSrr' OFFICE frooL Foa s'rRAIGHTENnvG WELL BoREs Jesse C. Wright, Los Angeles, Calif.; Martha H. I Wright, executrx of 'JesseC. Wright, deceased, distributed by court order to Martha H. Wright,

widow Application'oetobr 1o; 193s, serial No. 105,033

12 claims. (c1. 255-61) This invention relates tok a well drilling tool and relates lmore particularly to a tool Ifor straightening Well bores. A general object of this invention is toprovide Va simple, practicalk tool is rapid and eflicient in straightening crooked or inclined Well bores.

Most deep well such as oil wells and gas Wells are crooked or inclined, in whole or in part, due

to the character of the earth formation pene- 10.

trated, and thetendency of the drilling tools to take inclined paths when they encounter inclned strata. Various methods and tools have been proposed for straightening crooked well bores, but have proven costly or only partially e`ective.

Another object of this invention is to provide a tool for straightening crooked or inclined well bores that digs into and erodes the side Walll of' the bore to make it straight or vertical;

Another object of this invention is to provide a tool for straightening crooked Well bores that is adapted to be rotated and moved longitudinally in the Well and that embodies a weighted body which constantly urges or feeds the active parts of the tool toward a vertical position.

Another object of this invention is to provide a tool of the character mentioned that embodies a very heavy stem or drill collar connected with.

the drilling string by a. universal joint 'or flexible connection and cutting parts carried by the drill collar that are urged against the side Wall of the bore by the tendency of the weighted drill collar to assume a vertical position and, therefore, cut

and scrape away the formation to make the bore vertical. Another object of this invention is to provide a tool of the character mentioned that embodies.

fluid'discharge ports adjacent` the cutting parts that discharge jets of fluid against the side wall of the bore to erode away the earth formation being acted upon by the cutting parts.

Another object of this invention is to provide a4 tool of the character mentioned in .which the' Weighted body .or drill collar carries blocks of a high specific gravity whereby the heavy gratitational force tending to return the drill collar to a vertical position urges the cutting parts against the side wall of the well bore to effect their rapidv Well, straightening i901 .that ample and, inge,

, companying drawings, in which:

pensive and that is capable of employment with typical rotary well drilling equipment. y

A further object of vthis invention is to provide atoolv of the character mentioned having a cutting unit or bit Aembodying self-sharpening eut ting teeth that arev adaptedfto .have maximum penetration of the formation at the side wall of the bore under a minimum force feeding them into the formation.

Another object of this invention is to provide a tool of the character mentioned in which the teeth of the bit are in staggered relation to have engagement with `,the side wall of the bore throughout a substantial vertical distance during each rotation of the tool. y y

Another object of this invention is to provide a ytool of the character mentioned embodying a Well straightening tool embodying ar flexible connection with the drilling string comprising drill pipe or the like of less diameter than the string y which it may lbe subjected and a quantity of lead or similarmaterialin the shell having laspeciiic gravity greater than steel whereby the drill collar isV of great Weight. and yet may be relatively short. y Y,

A further object of this invention is to provide an improved drill collar for use with well drilling and well straightening 4tools that has a very great weight and yet hasaminimum length, whereby the weight for feeding the tool is concentrated immediately above the tool. y

The various objects and features of my invention will be fully understood from the following detailed description of typical preferred forms andk applications of my invention, throughout which description reference is made to the acvFig. 1 is a side elevation of one `form ff the invention in theA operative positionin awell.

Fig. 2 is a fragmentary enlarged longitudinal detailed sectional View of the lower portion of the tool illustrated in Fig. l. Fig. 3 is an enlarged fragmentary longitudinal sectional view of the knuckle joint being a view taken as indicated by line 3-3 o-n Fig. 1. Fig. 4 is an enlarged fragmentary longitudinal detailed sectional view of the upper portion of the body or drill collar illustrated in Fig. 1. Fig. 5 is a transverse detailed sectional View taken as indicated by line 5-5 on Fig. 2i. Fig. 6 is a side elevation of a slightly modified form of cutting unit for embodiment in the tool illustrating the sleeve and teeth in longitudinal cross section. Fig. 'i' is a transverse detailed sectionalview taken ,as indicated by line 'I-I on Fig. 61. Fig. 8 is a View similar to Fig. 1 illustrating another form of the invention in the operative position-in vthe well', and Fig. 9 is an enlarged fragmentary longitudinal detailed sectional View of a portion of the tool illustrated in Fig. 8.

The form of the present invention illustrated in Figs. 1 to 5, inclusive, of the drawings, includes, generally, a heavy drill collar or body I0, a knuckle joint oruniversal joint I I connecting the upper end of the body I0 with a drilling string S, anda cutting and eroding unit or bit I2 on the lower end of the body IB.

The drill collar or body Il) isV an important element of the tool as it supports the `bit I2 and provides a great weight for urging the bit laterally against the side wall of thewell bore W, if the bore is inclined, and for holding the bit vertical in a vertical bore. The body I3 is an elongate structure or assembly and in practice may be from 20 to 40 feet, or more, in length.

The drill collar or body I0 is proportioned to fit the well bore W with substantial clearance ,leaving a suitable space for the circulation of fluid. In accordance with the invention the body IIl includes an outer part or shell I3. The shell I3 is tubular and may be formed of one or more lengths of drill pipe or the like. Theshell I3 is operable to transmit the `torque or rotational strains to vwhich the tool is subjected and has means at its upper end for connecting with the knuckle joint II and means at its'lower end for carrying the bit I2. In the particular structure illustrated in the drawings a sub or connecting member III' is threaded in the upper end of the body shell I3 and a similar sub I5 is threaded in the lower end of the shell. The sub I4 is reduced in diameter between its ends to present a downwardly facing annular shoulder I6 engageable by a shing tool in the event the tool becomes lost in the well. from the body shell I3 and is provided at its lower end with athreaded pin I'l. A central longitudinal fluid passage IBI extends through the sub or member I4 and its lower end has communication with the interior of the shell I3. A longitudinal fluid passage I 9 extends through the connecting member I5 to the lower end of its pin I'I.

The drill collar or body IIJ further includes weight elements or weight blocks 20. The blocks 20 are arranged in superimposed relation Within the shell I3. In the preferred construction the blocks 20 yare annular or tubular and have heavy walls. A thin-walled circulation pipe 2l extends longitudinally through the stack of tubular blocks 20 and its lower end is threaded in a collar 22. The collar 22 has a downwardly and inwardly tapered lower end tting a correspondingly shaped socket 23 in the upperrendof the connect- The sub I5 extends` downwardly' ing member I5. The multiplicity of blocks 20 is supported on the collar 22. In practice a washer 24EL may be interposed between the lowermost block 2D and the upper end of the collar 22. The wash pipe or circulation pipe 2l and the collar 22 facilitate the assembly of the blocks 2i! in the shell I3. The lower end of the pipe 2l has communication with the upperend of the passage I9. The pipe 2l extends upwardly through the stack of blocks 2G to project above the uppermost block so that its upper end has communication with the passage I8.

The blocks 23 constitute the weight elements of the device and in accordance with the invention are formedl of a material having a high specic gravity., In practice the blocks 2Q are formed of lead or the like. It will be apparent how the elongate shell I3 .and the multiplicity of blocks 20 within the shell constituting the body III have a very great aggregate weight. The number of blocks 23y of course determines the weight of the bodyl I0 and any desired number of blocks may be employed. In practice the shellI I3 may be substantially lled with the blocks 20 so that the uppermost block is adjacent the lower end of the connecting member I4.A The blocks 20 may be fitted in the shell I3 around the pipe 2l to have little or noI movement or play in the body. The pipe2 Iy serves to conduct the circulation fluid downwardly through .the body Ilso that the blocks 23 are not eroded by the fluid. The tapered collar 22 fitting the socket 23 centralizes the pipe 2| and dependably seals off the lower end of the shell I3 sothat there can be no circulation of fluid past or around the blocks' 20.

The knuckle joint or universal joint I I connects the upper' end of the drill collar 4or body I0 withl the drilling strings to rotate with the string and yet assume any .angular position relative to the string at will. The joint II is such that the weight of' the body IIJ or vthe gravitational force acting on the body may at all times urgeit in the direction indicated by the arrow in Fig. 1 to maintain the active parts of the bit I2 in contact with the side wall of the well bore in a manner to straighten the bore. In accordance with the broader principles of the inventionthe joint' II may be varied considerably` in type and construction. `The particular joint II illustrated in the drawings includes an upper member 213 and a lower member 25.v yThe upper member 24 may be secured to the' lower end of the string S by a suitable sub 2B. A connecting member or sub 2l' connects the lower joint member 25 with the member III of the body I0. The upper member 24 is'providedin its lower end with a spherically concaved seat 28. A vspherically convexed head 29 is provided on the upper end of the member 25 and cooperateswith the seat 28. A sleeve 3U is threadedr or otherwise rigidly secured to the member 24 and extends downwardly beyond `its lower end. The sleeve 3i] has an internal spherically concaved surface 3| which cooperates with the head 29 to prevent longitudinal separation of the members 2li and 25. The cooperation of the .head 29 with the seats 23 and 3I permits' relative angular movement or universal movement between the members 24 and 25.

Means is provided for transmitting rotation and torque between the joint members 24 and 25. Longitudinal or circumferential grooves 32 are provided in the head 29 and blocks 33 shiftably cooperate with the grooves 32. Trunnions or pins-34 proiect'inwardly from the s1eeve3' and pivotally cooperate with openings 35 in the blocks .33. The pins34. cooperating with the blocks 33 in the gr0oves32 transmit rotation and torque between the members 24 and 25. A longitudinal uid passage 36 is provided inthe member Y2t. and has its lower end in communication with a similar passage 31 in the member 25. A'

sealing ring 38 may be providedon the head 2Q to cooperate with the seat 28 and seal about the communicating ends of the passages 36 and'3'i.

The passage 3S receives the circulation uid to the string so that the bit l2 may bear or acton the side wall of the well bore W under the heavy gravitational force exerted by the body when the welll bore is inclinedfr u The cutting unit or bit I2 is provided to cutI away and erode theearth formation at the side wall or" the well bore W to make the bore straight or Vertical. The bit l2 includes a carrier or manf drel 6). The mandrel 46 may be a simple, inte.-

ral member having a threaded socket 4l in its upper end for receiving the pin il of the connecting member l5. The major lower portion of the-y mandrel 48 may be enlarged in diameter. Suit- `able cutting teeth 42 may be provided on the lower end of the mandrel iii to act downwardly in the event the tool encountersV an obstruction in the well being straightened or the Atool is op `erated at the bottom of the bore. Cutting parts are provided on the mandrel 40 to act on the formation at the side wall of the well bore` W. These cutting parts may vary somewhat in character and may be secured yto `the mandrel 40 in various manners. In the preferred construction illustrated the major enlarged portion of the mandrel is provided vwith a plurality of longitudinal grooves 43. The grooves 43 may be equally spaced apart and extend downwardly'from the upper end of the enlarged portion of the -mandrel to a plane above the lower end of the mandrel. The side walls of the groovesv 4l? are outwardly convergent. serted in the grooves 43 from their upper ends and are adapted to bear on the bottom walls of the grooves. The opposite sides of the bars 44 are outwardly convergent and cooperate with the side walls or" the grooves to hold the bars against outward displacement. A nut t5 may be thread-v ed on the reduced upper portion of the mandrel 40 to cooperate with the upper ends of the bars 44. ment of the bars from the grooves 43.

Vertically spaced cutting teeth 4S are provided on the bars 4.4. The teeth 46 project radially or outwardly from the mandrel 4B to act on the earth formation at the side of the wall bore W. The teeth 4B are pointed, having flat or lwash away the formation.l

Blades or bars M are in- The nut 45 prevents longitudinal displace- As the teeth 45 wear the metal 8 pro-` when the toolis rotated or moved longitudinally in the well.

`The bit I2 is provided with means for discharging jets of .fluid under pressure against.

the side wall of the well bore to erode the formation and aid the cutting teeth. A longitudinal passage lll extends through the mandrel '4B' from its socket 4l where it has communication with The passage the lower. end of the passage I9. il terminates above'the lower end of the mandrel 4e. Lateral or radial ports 48 vare provided in the mandrel 4l! and extend outwardly from the passage lll to the periphery of the mandrel. 'Ihe ports 4S may be relatively small in diameter to discharge jets offluid under high velocity. The ports 43 may bein different horizontal planes and if desired may be arranged in a spiralled' series, as illustrated. The ports i8 discharge at' points between adjacent toothed 'bars 44.

In operation the tool illustrated in Figs. 1 to 5,l inclusive, of the drawings may be connected with a rotary drilling string S, as illustrated in the drawings?, and lowered through the well to the portion of the well to be'straightened. When the tool is in the desired .position vin the well water or circulation fluid under pressure is pumped downwardly through the. string S to discharge from the ports d8. .The string S is rotated in the kusual manner to rotate 4the tool inthe well. As

the tool rotates the :teeth 46 engage and `cut away the formation at the side wall of the well bore and the jets of fluid from the ports 48 erode Gravitational force acting upon the heavy tiltably suspended body l0 constantly urges the body to a vertical position and, therefore, constantly feeds the unit l2 laterally against the wall of the well bore W.

'46 may act upon a substantial portionv or length of the inclined wall of the bore. The circulation of fluid, the rotation of the string S and the reciprocation of the string S may be continued until the cutting parts or teeth 46, acting in lconjunction with the jets of fluid discharged from the ports 48 cut the well bore to avertical or substantially vertical line, as indicated bythe dotand dash line in Fig. 1. Throughout the entire operation the tendency of the extremely heavy body l0, connected with the string S by the flexible joint il to return to a vertical posi-` tion eiectively feeds the bit I2 into cutting and eroding engagement with the side wall of` the well in a direction necessary to make the bore vertical. The above described operation may continue until the `selected inclined portion of *thek well bore is vertical whereupon the tool may described above.

facing shoulder 50 is provided on the mandrel a short distance above its lower end. Clutch parts or lugs 5I project upwardly from the shoulder 50. The bit I2a includes a sleeve 52 passed f downwardly over the mandrel 40u to rest on the shoulder 5i). Notches 53 are provided in the lower end of the sleeve 52 to receive the lugs 5I whereby the sleeve 52 is rotated with the mandrel. A nut 55 may be threaded on the mandrel 45a `to engage the upper end of the sleeve 52 and hold the sleeve in proper engagement with the shoulder 50. Vertical series or rows of outwardly projecting cutting teeth 56 are provided on the sleeve 52. The teeth 55 may be similar to the abovedescribed teeth 46. The teeth 555 may have shanks 5l set in openings in the sleeve 52 and may be welded to the sleeves as illustrated. Openings 9a extend through the teeth 56 and contain hard cutting materialv 8a whereby the teeth are self sharpening through use. The teeth 58in the adjacent rows may be staggered or vertically offset. Cutting teeth 58 may be provided on the lower end of the mandrel 45a to act on the bottom wall of the bore and to cut through i any obstruction that may be encountered in the Well bore being straightened. The unit illustrated in Figs. 8 and 9 operates in the same manner as the unit I2. The sleeve 52 may be readily removed from the mandrel llll1 when it is desired or necessary to replace the cutting teeth 56.

Figs. 8 and 9 of the drawings illustrate another form of the invention. In the structure illustrated in Figs. 8 and 9 of the drawings the body Ill and the bit I2 may be substantially the same as If desired the body I5 may be somewhat shorter than the body in the tool disclosed in Figs. 1 to 5, inclusive. In the apparatus illustrated in Figs. 8 and 9 the upper end of the bodyv I0 is connected with the string S by `a pipe P. The pipe P is of less diameter than the pipe in the string S whereby it may' more freely flex and has substantial clearance in the Well. The pipe is suiiiciently long to have the required flexibility whereby the body IE! may return to a vertical position under the gravitational influence. A cutting unit or bit I2b is connected between the lower end of the pipe P and the upper end of the body I5 whereby the tool includes the vertically spaced bits I2 and I2b. The bit I2b may resemble the bit I2 including a mandrel 55 and toothed bars 6I set in grooves 62 in the mandrel. The mandrel 60 is provided with connecting means at its opposite ends. The upper end of the mandrel 69 may be connected with the lower end of thepipe P through the medium of a suitable sub B3. A pin 64 may be provided on the lower end of the mandrel 60 to cooperate with a socket 55 in the upper end of a sub 66. The sub 66 is in turn threaded in the upper end of the body shell I3. The bars 6l are provided with series of vertically spaced self-sharpening cutting teeth 6l and are locked in the grooves 62 by a nut 68 threaded on the mandrel to bear against their' upper ends. In practice the toothed bars BI may be identical with the above described bars 44. A central longitudinal fluid passage 'IIJ extends through the mandrel 5i) to conduct the circulation fluid from the pipe P to the pipe 2l of the` body I9. If desired or believed necessary radial or lateral ports 7l may be provided n the mandrel 60 to communicate with the passage lll. The ports 'H may discharge jets of circulation fluid under pressure outwardly from the mandrel B0 to erode the yformation at the side wall of the well bore. A pilot bit of reduced diameter extends from the lower end of the bit I2. The pilotbit 80 is operable to drill through any obstructions that may be encounteredk and is intended primarily to start the bore in a vertical direction after the previously drilled portion of the bore has been straightened. Theoperation of the tool illustrated in Figs. 8 and 9 of the drawings is substantially the same as that of the previously described form of the invention. In operation the tool is rotated in the well and may be moved up or down from time to time. The gravitational force acting upon the heavy body I constantly urges the body toward a vertical position and, therefore, it urges the cutting parts of the bits I2 and I2b against the wall of the well bore so that they rapidly cut the bore to have a vertical axis. The pipe P freely fexes allowing the body I0 to return to the vertical position, as described. The tool illustrated in Figs. 8 and 9 is particularly rapid in operation as it involves the vertically spaced cutting bits I2 and I2". The bits I2 and I2b acting on the formation at vertically spaced points may assist in stabilizing the tool to more rapidly straighten the well bore.

Having described only typical preferred forms and applications of my invention I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

l. A tool for straightening crooked well bores comprising, a body, a weight element of a higher specic gravity than ferrous material carried by the body to turn therewith, a flexible connection for connecting the body with a drilling string whereby gravity may urge the body laterally toward a vertical position when in an inclined bore, and vertically spaced cutting means on the body for acting laterally against the earth formation at the side wall of the well under said gravitational urge.

2. In combination, a rotary well drilling string, an elongate body` having a higher specific gravity than ferrous material, a flexible connection between the body and the string, and vertically spaced bits carried bythe body for acting on the earth formation each including laterally projecting cutting parts and laterally directed fluid discharge means.

3. Well straightening` apparatus including, a rotary drilling string, a drill collar having an aggregate specific gravity greater than ferrous material, pipe of less diameter than the string rigidly connected with the drill collar and the lower end of the string and forming a limber connection between the string and the drill collar, and laterally projecting cutting elements on the drill collar urged laterally against the side wall of the well by gravitational force tending to return the drill collar to a vertical position.

4;. A drill collar for use in a rotary well drilling string comprising, a tubular member of sufcient strength to transmit the torque and longitudinal forces to which the string is subjected, coupling means on the upper end of the member for connecting it with the drilling string whereby the member is rotated by the string, and a weight element of a higher specic gravity than ferrous materials within and supported by the member.

5. A drill collar for use in a. rotary well drilling string comprising, a tubular member of sufficient strength to transmit the torque and longitudinal forces to which the string is subjected, coupling means on the upper end of the member for connecting it with the drilling string whereby the member is rotated by the string, and a plurality of blocks in and supported by the inember of a higher specific gravity than ferrous metals.

6. A drill collar for use in a rotary well drilling string comprising, a tubular member of sufcient strength to transmit the torque and 1ongitudinal forces to which the string is subjected, means for connecting the member with the string to be rotated thereby, `a fluid circulation tube extending longitudinally through the member, and a weight element in the member having a higher specic gravity than ferrous materials.

7. A drill collar for use in a rotary well drilling string comprising, a tubular member of sufcient strength to transmit the torque and longitudinal forces to which the string is subjected, means connecting the upper end of the member with the drilling string whereby the member is rotated by the string, a fluid circulation tube extending longitudinally through the member, and a stack of tubular weight blocks in the member around the tube.

8. A drill collar for use in a rotary well drilling string comprising, a tubular member of sufficient strength to transmit the torque and longitudinal forces to which the string is subjected, means connecting the upper end of the member with the drilling string whereby the member is rotated by the string, and a plurality of tubular weight elements in the member dening a 1onbody material having a higher specic gravity than ferrous metals carried by the body, a flexible connection between the body and the string, and a cutting unit carried by the body and including horizontally projecting teeth spaced vertically of the unit, the outer active ends of the teeth being substantially the same distance from the vertical axis of the body.

l0. Apparatus of the character described for use on a rotary well drilling string including, a

body carrying material having a higher specific gravity than ferrous metals, a ilexible connection between the body and the string, anda cutting unit carried by the body and including cir- -cumferentially spaced rows of vertically spaced teeth projecting laterally from the unit to act on the side wall of the bore, the outer ends of the several teeth being substantially the same distance from the vertical axis of `the unit.

l1. Apparatus of the character described for use on a rotary well drilling string including, a drill collar body carrying material having a higher specific gravity than ferrous metals, a iiexible connection between the upper end of the body and the string, and cutting units on the upper and lower end portions of the body, the cutting units having laterally projecting cutting parts.

l2. Apparatus of the character described for use on a rotary well drilling string including, a

.downwardly from the member.

.JESSE CQWRIG'HT,

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