US2355342A - Drilling apparatus - Google Patents

Description

Aug.8,1 `944. QWVAN WORMER V2,355,342

DRILLING APPARATUS Aug- 8, 1944. c. w. vVAN woRMr-:R Y 2,355,342 I DRILLING APPARATUS Filed June l5, 1942 3 Sheets sheet 2 44 {v f' 45 "4a '@Y t 5 3 45 4g l: E .6 F l5 .8

e. w. VAN woRME-R 2,355,342

\ DRILLING APPARATUS A Filed June 15,1942 3 Sheewsheeft 3 l A P IEJO 44 am nf. mv www@ l I NVENTOR. I

` .'/QrrogP/V drive shaft.

It has been proposed to operate a rotary drillA Patented Aug. 8, 1944 UNITED STATES PATENT OFFICE This invention relates to drilling equipment for drilling wells and the like and has for its general object the provision of a drilling equipment constituting an improvement over the presently known rotary equipment for drilling wells.

In the most widely used rotary drilling equipment, power is transmitted through a rotating drill stem, or long pipe from the surface of the earth, and the cuttings from the drill are washed out of the hole by slush circulated through and around the drill stem. Manydiliculties and objections arise in connection with such equipment, due principally to the use of such a long bit by means of a motor located in the well adi jacent the bit, but previous attempts to do this have not resulted in wide spread use because of such diiculties as getting a. motor of sufficient power and proper operating characteristics in the limited space available, supplying power thereto, dlssipating heat therefrom in the presence of high temperaturesin the surrounding earth, providing proper lubrication and arranging ior proper bearings in the limited space.

It is a more specic object of this invention to provide a drilling apparatus of the type last mentioned, in which the v.defects and difficulties referred to will not be present. l

It is a further object to provide such an apparatus which will be lighter, less expensi e, more easily portable, more durable and troub e free, and require less amount of critical materials than drilling equipment of similar capacity heretofore produced.

A further object is to rprovide an apparatus which will make 'it possible to drill wells deeper, more accurately, and with greater safety.

Other objects and advantages of this invention will became apparent form the following description taken in connection with the accompanying drawings wherein is illustrated by way of example one embodiment of the invention.

In the drawings:

Fig. 1 is a longitudinal cross section through the upper end portion loi' a drilling mechanism constructed in accordance with this invention.

Fig. 2 shows a continuation of the lower por-.D

tion of Fig. 1.

Fig. 3 shows a continuation of the lower portion of Fig. 2. l

Fig. 4 is a horizontal cross section taken alon the line I-I of Fig. 1.

Fig. 5 is a horizontal cross section taken along the line 5-5 of Fig. 1.

- Fig. 6 is a horizontal cross section' taken along the line S-B-of Fig. 1.

Fig. 7 is a horizontal cross section taken along the line 1 1 of Fig. 2.

Fig. 8 is a horizontal cross section taken along the line 8-8 of Fig. 2.

Fig. 9 is a horizontal cross section taken along the line 9-9 of Fig. 3'.

Fig. 10` shows a longitudinal cross section through a well bore being drilled by a mechanism constructed in accordance with this invention, such mechanism in this instance being illustrated on a reduced scale and shown in side elevation.

Referring now more in detail to the drawings,

-it will be seen that the major portion of the device is enclosed within an outer housing I having an outer head 2 welded or otherwise secured to its upper end. Within this outer housing and arranged in concentric spaced relation with respect thereto is the inner housing 3. Secured in a manner hereinafter to be described to the lower ends of the outerand inner housings I and 3 isa lower bearing housing 4 which extends downwardly a considerable distance below the inner and outer housings I and 3. The outer head 2 also has a part extending over the upper end of and down within the inner housing 3 as clearly illustrated in Fig. 1.

Disposed 'within the-outer head 2 and extending downwardly Within the inner housing 3 is the-v4 inner head 5, 'the upper end of which projectsA upwardly beyond the outer head 2 and is threaded to receive the lug couplings. The lug coupling 6 is secured to `the outer head 2 by means oli cap screws 'I which extend through a flange in the lug coupling 6 and are threaded into the outer head 2. The lug coupling 6 on its upper end is threaded `to receive the lower" end of a section of drill pipe 8.

An` offset electrical conduit pipe section 9 of substantially S-shape extends through an opening provided therefor in one side of the lug coupling 6 and is welded to the lug coupling 6 about said opening so as to provide a seal with respectthereto. At its lower end this pipe section 9 is provided with a coupling I0 for a purpose presently to be stated. pipe is for the purpose of passing an electrical conduit or cable II from the exterior of the lug coupling 6 to the interior thereof. YA seal between the cable and the outer end of the pipe is provided by means of a conduit coupling l2 threaded on to the outer en d of the pipe and serving to bind the pipe tightly around the electrical cable.

'Iihe lower end of the electrical cable is separated into the various wires which extend therethrough and these wires as individual conductors I3 are spread apart and caused to extend through circumferentially spaced openings in the electrical distribution housing I4. The lower portion of the electrical cable Il below the pipe section 9 extends through a lower electrical conthe pipe 9 by means ofthe coupling In. This conduit section I5 extends from the plpe 9 sub- Y stantially to the lower end of the cable as a unit.

Threaded to the lower end of the electrical distribution housing I4 is a circulator housing I6 having grooves formed in its outer surfaces which are of a size to receive the vVarious electrical conductors I3. These grooves extend longitudinally of the outer surface of the circulatorhousing I6 and serve to-carry these electrical conductors I3 downwardly toward the motor in a manner which will be presently described more in detail.

Threaded into vthe lower end of the circulator housing I6 is the upper ven d of the upper bearing housing I1. IThe lowe'r end of this bearing i formed with a square or other non-circular cross section adapted to t into a socket of corresponding shape in the lower end of the upper bearing n f housing is adapted to be closed by means of anrannular plug I8 whichin turn is held in lplace lines 32 of which there are two as will be clearly illustrated in Fig. 6. These oil return lines likewise extend upwardly through the space between the outer and inner housings I and 2 and conduct the oil from the bearings back into the oil reservoir 29.

Mounted within the lower end of the circulator housing I6 is the'air circulator 33. This circulator 33 is carried on the air circulator shaft 34, the upper end of which is provided with a coupling 35 by means of which this air circulator shaft 34 is joined to the oil circulator shaft 38 that extends upwardly to operate the oil circulator. 'I'his shaft extends upwardly through the tubularV conduit 31 which is disposed centrally within the oil reservoir 29, making the oil reservoir of annular cross section. This tubular member 31 is preferably welded or otherwise seshaft 22. This upper bearing shaft as compared with the' motor shaft; 2| is of relatively larger diameter so that it will accommodate adequate curely sealed at'its lower end tothe oil plug of disk 38 which closes thelower end of the oil reservoir. The outer' edges of this disk or plug 38 are sealed with respect to the inside of the circulator housing I6 so as to provide a closed oil reservoir 29.

The air circulator 33 is adapted to take air in through the air intake pipes 39 and to discharge it through air discharge pipes 40 which extend radially from the air circulator out through the circulator housing I8 and the inner housing 3 Vinto the annular space between the outer and inner housings I and 3. The pipes 49 then extend Y* downwardly through this annular space to a bearings. vThe lower end of the motor shaft 2| f 'is likewise formed with a square or other noncircular cross section for the purpose oflttingv l within a socket in the Vupper end of the lower bearing shaft 23. The lower ybearing shaft l231 like the upper bearing shaft 22 is of relatively larger diameter than themotor shaft y2| in order that adequate bearings may be providedfor the support of these three shafts. These bearings are indicated generally by means of the numeral .24 and may substantially all be formed as conical roller bearings. In addition to these bearings there is also shown at the upper end of the shaft 22 a ball thrust bearing 25, the upward thrust from the shaft 22 being conducted to the bearing 25 through a nut 26 which provides a shoulder on which the lower bearing race may rest.

Referring now again to the circulator housing oil reservoir 29. This oil pump or circulator 21 is adapted to draw oil from the reservoir 29 through the oil suction pipe 30 and to discharge the same through the oil discharge lines 3| which extend through the housing I6 and the housing 3 in a radial direction into the annular space between the outer and inner housings I and 3 and thence downwardly through this space. As will be seen clearly in Fig. 6, there are two such down- Wardly extending discharge lines from the oil. circulator 21, one of these extending downwardly and emptying into the upper end portion of the upper bearing housing I1 andthe other-extending downwardlyA and emptying into the upper end portion of the housing for the lower bearings 24;V Leading upwardly from the lower ends of each of such bearing housings are oil return point Vadjacent the lower end of the motor where `the air is discharged' into the motor housing and passes upwardly through the motor to the upper end of the motor housing where it enters the inv shaft 23 and Vthreadedly secured thereto is the drill bit coupling 4|. This drill bit coupling is provided with an annular slush groove 42 which is open upwardly and which communicates with downwardly and inwardly extending slush passageways 43. 'I'he drill bit coupling 4| is provided with a. threaded socket at its lower end adapted to receivevthe pin on a drilling bit 44 which may be of any desirable type.

The inner and outer housings 3 and I are held in accurately spaced relation by means of spacer rings or flanges 45 placed therebetween at spaced intervals along the length of the device. These rings 45 may be welded or otherwise secured to the inner housing 3 if desired. They are illustrated as being secured to the outer housing I by means of the spacer ange screws 46. The space thus provided by these spacer rings provides a water jacket 41 between the outer and inner housslush nipples 49 which conduct the slush froml the interior of the inner head 5 in a radially outward direction into the interior of the water or slush jacket 41.

The lower end of the lower bearing housing is closed against the leakage of lubricant therefrom by means of the oil seal rings 50 and the composition packing rings which are disposed within the housing 4 and about the lower end of the shaft 23.

The housing 4 has longitudinal passageways through its wall asshown at 48 which correspond to the openings 48 in the spacer anges 45. These passageways conduct the slush downwardly from the slush jacket 41 to the lower end of the housing 4. This lower end of the housing 4 is slightly reduced in its radial cross section so as to fit within the annular groove 42 in the upper end of the drill bit coupling 4|. The drill bit coupling 4| is intended to rotate with respect to the body 4 but the leakage of slush from the joint between these two parts is prevented by means of theinner and outer sealing rings 52 which may be of rubber, or some suitable composition and which are illustrated as being located in grooves provided for the purpose in the opposite walls of the annular slush passage 42. Thus it' will be seen that even while the drilling bit collar 4| is being rotated during the process of drilling, slush may be in the openings through the inner housing by pumped downwardly through the slush jacket 41, through the openings 48 and into the annular slush passage 42 in the drill collar and thence into the drilling bit, without being permitted to leak out between the body 4 and the drilling collar 4|.

Hooked over the lower end of the inner housing 3 and having a part disposed within the lower end of this inner housing and the inner upper end of the housing 4 is an inverted cup shaped lubricant retainer 53. This retainer has in its upper end an oil seal ring similar to those heretofore mentioned which provides a seal aboutfthe lower portion of the motor shaft 2| to prevent the leakage of lubricant upwardly along this shaft.

Against the lower end of this lubricant retainer there is disposed va thrust bearing sleeve 54 having an 4inwardly extending ilange at its upper end adapted to receive the upper bearing race of the maior thrust rollerbearing. This bearing like the thrust bearing heretofore referred to has its lower race carried on a nut 26 on the shaft 23 so that a thrust load is transmitted from the shaft 23 through the nut 26 to the lower bearing race and thence through the rollers to the upper bearing race and to the thrust bearing sleeve flange 54. I

The packing rings 50 and 5| adjacent the lower end of the body 4 are held in place therein by means of an' annular packing retaining plug 55 threaded into the body 4. This plug is in turn locked in its threaded engagement with respect to the body 4 by means of set screws 56.

The inner housing 3 is anchored to the body 4 by means of one of the spacer flanges 45 which is welded to the body 3 adjacent its lower end and which has openings therein for the purpose of receiving the studs 51 having nuts 58 on their upper end. These studs 51 are in threaded engagement with the upper end of the body 4 so that when the nuts 58 are tightened the inner housing 3 will be tightened against the upper end of the body 4.

It will be noted that the set screws 59 are employed within the inner head 5 for thepurpose of retaining the slush nipples 49 in place therein. It will further be seen that set screws 60 are extended through the wall I6 to secure the air circulator 33 in place therein.

The oil discharge lines and oil return lines 3| andn32 respectively are passed through the inner housing 3 and a seal is formed about them withmeans of bushings and nuts 6|.

Carried within the inner housing 3 below the circulator housing and below the upper bearing housing |1 is the motor stator frame 62. This motor stator frame 62 as illustrated more in detail in Fig. 7 is provided with slots along its inner surface thereby forming tongues on which the stator winding 63 is carried. A

Carried on the motor shaft 2| within the stator winding is the rotor frame orfvspider 64. This spider has circulation holes 65 extending longitudinally therethrough so as to permit the circulation of air or other inert gas for a purpose pres-V ently to be set forth. Surrounding the spider 64 is the armature core 66 in which are formed grooves 61, the armature bars 68 being laid in these grooves. The amiature frame or spider is preferably keyed to the shaft 2| by means of a key 69.'

It will be understood that while reference is being made to armature parts, this term is to beunderstood as covering any type of rotor for an electric motor depending on which type of electric motor is to be employed. It is not intended that this invention shallbe limited to any one particular type of electric motor although one type is hereinafter mentioned as preferable.

On the lower end of the rotor is a so-called end frame 10' held in place on the end of the rotor by means of bolts 1|, these bolts extending through certain of the holes 64 in the armature frame. On the end frame 10 are radially extending rotor Yvanes 12..

The stator is held nonrotatably within. the inner hohsing by means of keys 13 inserted between the stator frame land the inner housing 3.

It will be appreciated that' the armature end plates 14 which are located above the end frames l 10 on which the rotor vanes 12 are carried, serve*l any resistance desired may be connected between the conductors I3 leading from the brushes 16, and this resistance may be provided at the sur- `i'aceof the ground where it will not tend to heat up the mechanism actuallysupplying the power to the drilling bit.

More specically, ifl it be considered that the motor is of a three phase induction type, then the electrical cable should be providedwith six conductors therein. Three of these conductors would, of course, be connected`to suitable portions of the stator windings and the other three to the brushes 16 which engage the collector rings 15.

The power supply would be connected to the three conductors of the electrical cable which are connected to the stator. Those three conductors which lead from the brushes 16 would be connected to suitable variable resistances so that by variation of the resistances located at the surface of the ground, the of the rotor of this motor could be changed thereby changing its torque characteristics.

resistance factor The brushes it will be noted are mounted on the y brush holding frame 18,. y

It is thought that the operation `of the device herein described will be clear from the foregoing description, but by way of further explanation of the operation thereof it mit!!v be 'stated that the mechanism described is lowered into the earth as the drillingcontinues, being suspended by means of the drill pipe 8 or other suitable tubular member. During this time the motor is operated to rotate the drill bit 44 but the drill pipe or tubular member 8 is not rotated and merely serves to take the reaction torque from the drilling operation. During the drilling operation the circulator 2lv serves to cause a lubricant flow from the reservoir 2S through the conduits 3| to the bearings 24 and to flow back to the reservoir 29 through the conduits 32. At the same time the circulator 33 will cause a flow of air or some inert gas through not'be capable of supporting the weight but which 'would bevcapable of taking the reaction torque from the drilling equipment, then a cable or the like may be secured to one or more of the lugs 11 provided for that purpose on the lug coupling 6 at the upper end of the device. It will be appreciated that inasmuch as the reaction torque necessary to be taken by the tubing on which the device is carried is relatively very small compared to that which would be necessary to take on a drill stem of an ordinary drilling rig, this tubing may be made very much lighter than the usual drill stem, and the necessary support for the apparatus could be provided by a relatively light and easily handled cable secured to one of the lugs 11. In this manner a great deal of the necessary weight of the drilling equipment could be dispensed with with the consequent possibility ,of drilling a hole very1rnuch deeper than has the conduitsI 39 to the upper end of the motor housing, through the motor itself and especially through the openings in the armature thereof and upwardly through the conduits 40 back to the circulator. During this time slush will be pumped downwardly through the drilll stem and will pass down through the jacket 41 in which the conduits 3|, 32 and 40 are located. The lubricant and the gas just referred 'to' will serve to remove excess heat from the bearings and the motor and in passing upwardly through the jacket in which the slush from the surface of the ground is flowing toward the surface of the bit. these fluids will give up their heat thusacquired to the slush. The slush in turn will carry the heat away as it flows but through the drill bit and will retain the heat as it ows back to the surface of the ground around the outside of the drill pipe 8. The slush will thus serve the double purpose of cooling the motor and bearingsv therefor and of washing the cuttings from the drill bit to the surface of the ground. In addition, it will also serve all the other functions that slush is called upon to perform in ordinary rotary drilling.

In order to control the torque characteristics of between the conductors from the brushes 16, such resistance, however, being located above the surface of the ground so that it can dissipate its the motor, a suitable resistance will be placed t heat to the atmosphere and so that it can be varied readily by the operator.

During the operation of the device the radial and thrust load from the drill bit will be taken by the relatively large and rugged bearings 2l located on the large drive shaft 23. end of the motor shaft 2| -will 4be supported by the upper relatively large shaft 22 carried by the upper set of bearings 2l. The motor shaft will thus be called upon to withstand only the torque stresses resulting from the operation of the motor and will be supported at both ends by the relatively large shafts 22 and 23 and the bearings in which these shafts operate. This makes for conservation of weight in the motor shaft and makes it possible for the motor shaft to be small enough in diameter so that an adequate motor structuremay bemounted thereon. At the same time itdoes not limit the bearing support for the driving shaft.

In the event a wellis to be drilled with the device just described which well is to be of exceedingly great depth such that the drill pipe l would be insuillcient to support the weight, or if it be desired to use a lighter pipe which would heretofore been possible.v Furthermore, it will be appreciated that inasmuch as itv is not necessary to transmit me` device has been described as being suspendedl upon a drill pipe or tubing, it might be carried upon any suitable form of tubular member or pipe or even upon a. substantially solid'rod, the only requirement being that4 the element -upon which it is carried be capable of taking the reaction torque from the drilling equipment and of supplying drilling fluid thereto.

It will further be appreciated that while the electrical conduit Il has been described as extending up the outside of the drill pipe or tubing, it may extend up the inside or certain suitable conductors may be incorporated within the tubing or pipe itself. Also, this conductor need not necessarily be all in one long piece but may be provided with`detachable connectors for connecting together a number of individual pieces.

By the use of the invention as hereinbefore described, it is possible to drill a well using much higher .drilling speeds because of the smaller amount of weight that is actually being rotated,

The upper and this higher drilling speed makes it possible (to use less weight on the drill bit without reducing the rate of penetration of tlie formation. This reduction of the weight on the drill bit not only reduces the wear and tear .on the bit itself but tends to produce a straighter hole with less variation from the vertical. Furthermore, in th event a cave-in should occur at some point above the drill bit, a twist-off would not be caused because the drill stem itself would not be rotating and hence if the application of power was not immediately stopped, there would be no danger of twisting off the drill stem.

A much lighter drilling equipment has been provided which makes for a tremendous Vsaving in'y the amount of steel and other critical materials that are ordinarily necessary to form a complete drilling outiit. It is estimated that for equipment for drillingl a Well of between nine thousand and twelve thousand feet deep, a drilling device constructed in accordance with the present invention would weigh somewhat less than half of the usual rotary drilling device withits necessary equipment.

It will further be appreciated that-while this invention has been described asl involving the use of a drilling device carried on the lower end of a drill pipe or tubing, it could be carried on the. lower end of any type of pipe located in the weil and might be secured to that pipe in any desired manner; Therefore. it is not intended that this invention shall be limited to the use of a drilling ydevice ofthe type set forth on any particular type of pipe.

From the foregoing descriptionit is furthermore apparent that a means has been providedl whereby power may be supplied to a drill bit at a point adjacent the bit itself without the necessity for transmittingrmechanical power from the top ofthe well to the bottomthereof, and that such a means as has beenl provided will not become' excessively heated both because of the factthat no excess heat is vgenerated and because of the fact that such heat as is necessarily generated will be carried off by the drilling iluid. In this connection it willbe seen that novel and highly satisfactory means for carrying away this heat both from the motorv and from the bearings therefor has been provided, while at the same time means has been provided for conducting drilling fluid from the surface of the well to the drilling bit so that it might pick up cuttings therefrom and convey them back to the surface of the ground.

All of the other objects and advantages of this invention will be found toA be `attained by the structure which has been described. It will be understood, however, that the structure described is by way of illustration and example only and is not intended to be by way of limitation of this invention. `This invention is to be limited only by the prior art and by the terms of the appended claims. l

Having described my invention, I claim:

1. In a drilling mechanism adapted to bese-` cured to the lower end of a nonrotating drill string, a body, means for securing the upper end of said -body to a drill string, a motor carried by said body and having a drive shaft extending downwardly therefrom and having its lower end adapted to receive a drill bit, a cooling fluid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive a drillingyiluid therefrom and the lower end in communication withthe interior of a drill bit secured to said shaft to deliver drilling fluid thereto.

2. In a drilling mechanism adapted to be secured tothe lower end of a nonrotating drill string, a body,means for securing the upper end of said body to a drill string, a motor carried by said body and having a drive shaft extending downwardly therefrom, a head on the lower end of said drive shaft adapted to receive a drill bit,

a cooling fluid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive a drilling uid therefrom, the head on said shaft having a passageway therethrough for conducting drilling fluid from said jacket to a drill bit secured to said head, and

to said body'whileluid is simultaneously flowing from said jacket intovsaidhead.

3. In a drilling mechanism 'adapted to be secured to the lower end of a nonrotatingdrill string, abody, means for securing the upper end of said body to a drill string, a motor carried by said-body and having a drive shaft extending downwardly therefrom andhaving its lower end adapted to receive a drill bit. a cooling fluid jacket around said motor within said body, means to supply fluid to said lacketand means on said shaft adapted to receive a drillingabit and to take fluid from saidl jacket and conduct it into said bit.

`4'. In a drilling mechanism adapted to be secured to the lower end of a nonrotating drill string, a body, means for securing the upper end' of said body to a drill stringa motor carj ried by said body and having a drive shaft ex- Icured to the lower end ofI a nonrotating drill having its passageways in communication with the lower en d of said jacket, and means forming a rotating seal between said head and said body both interiorly and exteriorly of said jacket whereby said head may be rotated with respect string, a body, means for securing therupper end tending downwardly therefrom and' having its lower end adapted to receive a drill bit, bearing means' for said shaft for rotatably mounting it within said body, said bearing means including an anti-friction thrust bearing adapted to transmit upward thrust from said shaft to said body, said thrust bearing kbeing located below said motor, a cooling fluid Jacket around said motor within said body, the upper end of said jacket being in communication with the interior` of said drill string to receive drilling fluid therefrom and the lower end in communication with the interior of a drill bit secured to said shaft to deliver drilling fluid thereto.

5. In a drilling mechanism adapted to be secured to the lower end of a nonrotating drill stringia body, means for securing the upper end of said body t'o a drill string, a motor carried by said body and having a. drive shaft extending downwardly therefrom and having its lower end adapted to receive a drill bit, bearings for mounting said shaft for rotation within said body, a cooling uid jacket around said motor within said body, the upper end ,of said jacket being in communication with the' interior of said drill string to receive drilling fluid therefrom and the lower end in communication with the interior of a drill bit secured to said shaft to deliver drilling fluid thereto, and means for circulating'a lubricant and a cooling fluid through said bearings.

6. In a drilling mechanism adapted to be sestring, a body, means for securing the upper end of said body to a drill string, a motor carried by said body and having a drive shaft extending downwardly therefrom and having its lower end adapted to receive a drill bit, bearing means for rotatably supporting said shaft within said body. a cooling fluid jacket around said motor within said body, the upper end of said Jacket being in communication with the interior of said drill string to receive drillingfluid therefrom and the lower end in communication with the interior of the drill bit secured to said shaft to deliver drilling fluid thereto, and means for circulating a lubricant through said bearing means to lubricate and ycool the same, said last mentioned means having a portion of its circuit extending through said cooling fluid jacket to coolthe fluid circulated through said bearings.

'7. In a drilling mechanism adapted to be secured to the lower end of a nonrotating drill of said body to a drill string, a motor carried by said body and having a drive shaft extendingv downwardly therefrom and having its lower end adapted to receive a drill bit, a cooling fluid jacket around said motor within said body, the

string, a body, means for securing thel upper end y I of said body to a drill string, a motor carried by said body and having a' drive shaft extending downwardly therefrom and having its lower end adaptedY to receive a drill bit, a cooling uid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive a drilling fluid therefrom and the lower end in communication with the interior of a drill bit secured to said shaft to deliver drilling uid thereto, means for circulating an .inert Ygas through saidwmotor during its operation, and means for circulating said gas through conductors located insaid cooling fluid jacket, whereby heat generated in-said motor will 'be dissipated y into the cooling uid passing through said jacket.

9. In a drilling mechanism adapted to'I be secured to the lower end of a nonrotating drill string. a body, means for securing the upper end of said body to a drill string, a, motor carried by said body and having a drive shaft extending downwardly therefrom and having its lower end adapted to receive a' drill bit, a. cooling fluid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive a drilling fluid therefrom and the lower end in communication with the interior of a drill bit secured to said shaft to 4deliver drilling uid thereto, bearing means for rotatably mounting said shaft within said body, means for circulating a lubricating and coclingl'fiuid through, said bearing means during operation of the device, means for circulating an inert gas through said motor during the operation thereof, and means .for causing both said lubricating and cooling V.fluid and said inert gas to be b'rought into intimate contact with the drilling uid circulating through said jacket,'whereby heat generated'in said mofor circulating a lubricating and cooling medium through said sealed enclosure about the bearing means during the operation of the device, whereby the bearing means may be lubricated and kept from overheating. 11. 4In a drilling mechanism adapted to be s ecured to. thelower end of a nonrotating drill string, a body, means for securing the upper end of said body to a drill string, a motor carried by said body and having a drive shaft extending downwardly therefrom and having its lower end adapted to receive a drill bitya cooling fluid-- jacket around said motor within said body, the upper end of ,said jacket being in communication with the interior of said drill string to receive drilling fluid therefrom andthe lower end in communication with the interior of a drill bit secured to said shaft to deliver drilling uid thereto, means forming a seal within said body above eration thereof to prevent said motor from overheating. 12. In a drilling mechanism adapted to be se- I cured to the lower end of a nonrotating drill string, a body, means for securing the upperl end of said body to a drill string,a motor carried by said body and having a drivev shaft extending downwardly therefrom, a head on said drive shaft having its lower end adapted to receive a drill bit, a cooling iluid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive drilling fluid therefrom, the lower end of said body and the upper portion of said head having telescoping relatively rotatable annular parts in engagement with each other, the annular part on the body having an opening therethrough communicating with said jacket, andthe part on said head having an opening therethrough adapted to communicate with a bit carried thereby, whereby drilling fluid will be Y said body and having a drive shaft extending downwardly therefrom, a head on said drive shaft of said body to a drill string, a motor carried by Isaid body and having a, drive shaft extending downwardly therefrom and having'its'lower end adapted to receive a drill bit, a cooling fluid jacket around said motor within said body, the upper end of said jacket being in communication with ling said shaft within said body, means forming a seal within said body above and below said bearing means and about said shaft to form a sealed enclosure about said bearing means, and means having a part adapted to receive a dri11 bit, a cooling fluid jacket around said motor within said body, the upper end of said jacket being in communication with the interior of said drill string to receive drilling fluid therefrom, said body and said head having telescoping relatively rotatable annular parts in engagement with each other, the part on said body having an opening therethrough in communication with said jacket and the part on said head having an opening therethrough in communication with a drill bit adapted to be secured thereto, and sealing rings of annular formation between said parts exteriorly of and interiorly of said openings respectively whereby fluid may pass from said jacket into said head during rotation of said headwithout iiowing out through the joint between said body and said head, and whereby said drilling fluid may then be conducted to said drill bit.

CARL W. VAN WORMER.

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