US2643087A - Self-powered rotary drilling apparatus - Google Patents

Description

June 23, 1953 H. J. oGoRzALY ETAL 2,643,087

SELF-POWERED ROTARY DRILLING APPARATUS Filed Dec. 22, 1950 3 Sheets-Sheet. l

i5 I A@ 45 ii s Il# ii 6 I fh* io 2 uzmwmmmmw l A H m QI. o z L 5 nxsfl y @Mmmm E-I-Gi Clbborner June 23, 1953 H. J. oGoRzALY r-:rAL 2,643,087

SELF-POWERED ROTARY DRILLING APPARATUS Filed D`eC. 22, 1950 3 Sheets-Sheet 2 #ISM-5 Fcvf June 23, 1953 H. J. oGoRzALY ETAL 2,643,087

SELF -POWERED ROTARY DRILLING APPARATUS Filed DBO. 22, 1950 5 Sheets-Sheet, 5

---p m 52A. ,M4 32 VALVE *45 Qbful. cltfuorne Patented June 23, 1953 SELF-POWERED ROTARY DRILLING APPARATUS Henry J. Ogorzaly, Summit, N. J., and Ben W. Sewell, Tulsa, Okla., assignors to Standard Oil Development Company, a. corporation of Dela- Ware Application December 22, 1950, Serial No. 202,173

(Cl. Z55-4.8)

6 Claims.

This invention concerns a novel apparatus for the drilling of bore holes, as conducted forexample, in the drilling of oil wells. This invention provides a drilling apparatus containing a stored supply of energy which is released at the bottom of the bore hole to power conventional drilling bits. The drilling tool or power supply units of the tool may be periodically removed from the hole in order to renew the store of energy. Drill cuttings are removed from the hole by means of bailing equipment. The entire apparatus may be operated in the bore hole without necessity for mechanical connection to any units at the surface of the earth.

At the present time, the majority of drilling operations are conducted by employing rotary drilling equipment. In conventional rotary drilling, a hollow jointed steel shaft called the drill stem is rotated from the surface of the earth. This shaft, extending downwardly into the earth to any desired depth, rotates a drill bit. For a number of purposes, a weighted fluid called drilling mud is circulated in one direction through the drill stem and in the opposite direction through the annulus between the drill stem and the bore hole. This general drilling technique is an extremely expensive operation. For example, a large capital investment is required to provide the high-power generating and transmitting capacity necessitated; to provide the necessary equipment to assemble, support, and turn the drill stem in the bore hole; and to provide the necessary apparatus for circulating the drilling mud. As a consequence of these and other factors, there is a demand for altera- I tions in drilling technique and apparatus of a nature to materially reduce the cost of drilling wells and to overcome many of the disadvantages of the rotary drilling method.

In accordance with this invention, these general objectives are satisfied by the provision of a novel drilling apparatus. As will be seen, the invention eliminates the necessity for employing the thousands of feet of drill stem hereto,- fore required, thus eliminating the necessity for the equipment heretofore required to support, turn, and to assemble or disassemble the drill stem. Again, this invention eliminates the necessity for providing the high capacity, high power pumping apparatus heretofore required for maintaining the circulation of drilling mud throughout the entire bore hole. Y

These objectives are achieved by a drilling apparatus which may operate as an integral, selfpowered unit in a bore ,hole without necessity for support or physical connection to any apparatus at the surface of the earth. Thus, the apparatus includes a stored power source, preferably a battery, operative to drive a motor. The motor performs a dual function; operating a pump positioned in the apparatus so as to secure a desired circulation of drilling mud in the vicinity of the bottom of the bore hole, and operating a conventional drilling bit. Operation is conducted by dropping the apparatus to the bottom of the bore hole and periodically removing at least a portion of the batteries for replacement by fresh units. Bailing is periodically or continuously carried out during drilling to remove drill cuttings preferentially accumulated adjacent the top of the drilling apparatus by virtue of the mud circulation provided.

In order to fully disclose the concepts of this invention, the accompanying drawings illustrating a preferred embodiment of the apparatus of this invention will be described. In these drawings:

Figure 1 diagrammatically illustrates in elevation, partly in section, the upper portion of the drilling equipment of this invention;

Figure 2 is a continuation of Figure 1 showing the lower portion of the apparatus, so that together, Figures 1 and 2 depict the integral apparatus;

Figure 3 is a section of Figure 1 along the lines III-III showing the nature of the friction dogs provided to prevent rotation of any portion of the apparatus except the drill bit;

Figure 4 is a cross section through the gear reduction system along the line IV-IV of Figure 2;

Figure 5 is a section of Figure 2 along the line V-V, illustrating the mud pump which may be employed; Y

Figures 6 and 7 show in elevation and in elevational cross section, respectively, a suitable type of bailing apparatus for use in removing the drill cuttings produced by the apparatus, and finally;

Figure 8 is an elevational view, partly in section, of a preferred arrangement for connecting the batteries of the apparatus.

Referring now to Figures 1 and 2 of the drawings, the general nature of the drilling apparatus may be understood. As illustrated, the entire integral apparatus is to be operated in a bore hole l in the earth. It is to be understood that, depending upon the progression of the drilling apparatus into the earth, bore hole I may be of any desired depth. As will be explained, the bore amaca? hole is maintained completely filled with a substantially static head of drilling mud. The actual drilling apparatus may be considered to consist of three assembled units. The lowermost unit may be identified as a motor section, above which is positioned a stored power source or a battery section and above which is an uppermost section operative to separate drill cuttings from drilling mud and to permit recirculation of the drilling.

mud to the bottom of the apparatus adjacentthc drill bit.

The motor section contains an electric motor 2 which is coupled to a mud pump 3 andto adrill bit 4 through a reduction gear'y systeme; ltfisA` contemplated that the electric' motorv may' be* directly coupled to the mud pump 3 while it is generally preferred that reducing gears'ibe em-l ployed so as to permit operation of the drill bit l at a speed less than the rotational speedof the motor. As will be understood, a passageway (5 extends completely through the apparatusxfrorn an upper portion thereof-to' a, point adjacent the drillibit l` at the lower portion of theaapparatus. Thus, drilling mud may be pulled downwardly through passagewayfito be Vdriven bythe. mud .3,

pump '3' towardl the drill bit l andv thence upwardly through'the bore hole. The top of the motor 'section is surmountedby a number of friction dogsfd whichtare .urged outwardly by springs so`asto'xthisportion ofthe apparatus in the bled' asxparallel annular-discs permittingl placement ofthe mud'conduit 6- through thecentral portion of the battery. Electrical connections to the. plates ofithe battery may be made in any desired manneras for example, by passage of electrical conductors through a clearance space provided at the outer terminations of theplates of the battery. It is convenient, for example, to assemble the` battery sections in units about l0 feet long. Connectors are providedateach endlof a given battery unit sothat additional units maybe connected and so that any desired number of units may be connected to the` motor section of the apparatus;V Variousprovisionsmay be made to permit a: portion but notxall' of the batteries to be removed. For example, as illustrated, the top of ka battery section may bef/pro vided with a spear head 3B, fitting within a hollow cavity ofthe next higher battery section. This permits removal of the upper battery` section while permitting retrievingof the lower. battery section' whenl desired. Byproviding, an. elastic sealing disc 3 I- at the top of the. cavity, the upper battery section may seatl on: spear` head, Sii'to connect conduit of adjacent battery sections.

For'v simplicity, the electrical connectionsbetween battery sections have not been4 illustrated in Figure l, although it `isapparent that the connectionsmay be made in anumber of ways.y A preferred manner of connecting the batteries will be described in connection with Figure 8. As battery packs of thisl general nature are well known, no further description will be offered as to this element ofthe apparatus. It may, however, be noted that the power capacity required is not unreasonable. The power requirements imposed on the battery consistA of the rotation areaof the-remainder of the equipment.

of the drill bit and the circulation of drilling mud through the apparatus and along the lower portion of the bore hole. However, these power reduirements are relatively low as compared to the power required in circulating drilling mud through the entire borehole and in rotating the tons of drill stem in thebore hole, as required in conventional rotary drilling operations.

Finally, in the apparatus of Figure l, a cutting separator section is employed as indicated by the numeral I0. The cutting separator section is simply an upwardly extending portion of the apparatusfhavinga"materially reduced cross sectional areaasl compared to the cross sectional As a result, drilling mudforced upwardly in the annular space between the motor or battery section and the bore hole, on entering the enlarged annularspace at the separator section will have a greatly reduced rate of flow. This will cause cuttingsv forced upwardly by theswiftly flowingdrilling' mudto preferentially. accumulate at the up'- per. section .of the apparatus. Thisreduced diameter section of the `apparatus thus essentially provides a settlingregion, from the upperrporition-of which drilling mud may be removed substantially free` of drill cuttings.' Consequently; by'placing, orices II at theuppermost portion of theapparatus. relatively clear drilling mud. may be pulled downwardly throughV channel 6 andi through thelmud pump for recirculation to the drillrbit il. As will be described, theV drill cuttings accumulating in the` separator section are periodically' or continuously removed from thissection by, forexample, a bailing technique.

It is preferred that centering springs.' I2 be positioned near the top of the apparatus. soy as to'maintain the apparatus in true alignment'with the bore hole. The springs may be leaf springs xed to collars sliding on shaft I0 to permitexpansion or contraction without buckling. Finally, a spear head I3 of the conventional type is provided at the top of the drillingapparatusso thata suitableretrieving-tool may be dropped downwardly into the bore hole tol permit pulling the-upperbattery section to the surface of the earth when desired forrenewalor replacement of the battery section.

`Inorder tofully disclose an operable'embodi'- ment l`-of thisV invention, the remaining figures of the drawings are concerned with essential. rnechanical details. Thus, Figure 3 illustrates 1a suitable arrangement ofl friction dogs to prevent rotation of any` portion of the apparatus other thanthe drill bit. As illustrated in Figure 3, a number of friction dogs- I may be arranged around a'central tubular supporting member I5. Itwill' be recalled that the central opening' of member I5 providesthe'necessary drilling mud conduit through this portion ofthe apparatus. Springs I6 are pla-ced between each of the'fric'- tion dogs "I and the support I5 so las toV urgethe friction dogs outwardlyv against the bore hole I. Thesefriction dogs are preferably designed so asftoihave vertical serrations Il of a nature' t'o permit thefapparatus to' pass upwardlyordownwardlyV in the bore holeI butto prevent rotation of the apparatus'. Alternatively, or as a modication, latching mechanisms may be provided to vnormally hold'the friction dogs in non-engaging position but to permit release of the friction dogs when the apparatus-*contacts the bottom of the bore hole.

Referring now to Figure 4, a section ofthe gear reducing system" for' coupling of the. motor valve.

to the drill bit is illustrated. Thus, a motor shaft 20, directly coupled to the motor drive is connected to the planetary gear system illustrated. As a result, the shaft 2| driven by the planetary gear system will turn at a reduced rotational speed. As planetary gear reducers of this nature are well known, no further description of this element of the invention is considered necessary.

Referring to Figure 5, a section of the mud pump is diagrammatically illustrated. The shaft of the pump 20 is directly coupled to the motor and is provided with 1a central passageway 6 through which drilling mud may flow into the pump. The impeller 42 connected to shaft 20 may be of the configuration shown in Figure 5, causing mud to be forced from the periphery of the pump, through lower channel 6a downwardly 'toward the drill bit.

Figures 6 and 7 illustrate a suitable form of bailing apparatus to be used in removing the drill cuttings from the cuttings separator portion of the apparatus heretofore described. As shown in Figure 7, the bailer comprises an upper evacuated chamber 48 joined to or integral with a downwardly extending hollow portion 4I suitable for passing over the spear head I3 and separator section I0. Fluid passageway to chamber 40 is provided through suitable conduits and valve mechanism 32. A suitable valve assembly may consist of a slide valve 33 normally closing conduit 34 by virtue of spring 35 maintaining valve 33 in its downward or closed position. Port 43 in valve 33 is provided to equalize the pressure across the As a result of this assembly, when the integral bailing apparatus is lowered downwardly in the bore hole over the spear head and over the centering springs of the drilling apparatus, the spear head will cause operation of slide Valve 33 to permit fluid adjacent the spear head to flow upwardly through conduit 34 into chamber 40. This flow occurs since chamber 4G may either be evacuated or simply lled with air at atmospheric pressure so the drilling fluid will be forced into the chamber under the high pressures existing at the bottom of the bore hole. The preferential concentration of drill cuttings beneath spear head I3 as formerly described permits the bailer to directly remove the greater part of the drill cuttings from the bore hole. bailer is repeatedly lowered to the bottom of the bore hole to remove these cuttings at whatever rate is required.

Referring now to Figure 8 of the drawings, a preferred manner of connecting the individual battery units and the motor section of the apparatus is illustrated. It may be noted that in Figure 8 the portion of the apparatus shown is intermediate battery unit 8 and the motor section surmounted by the friction dogs l. Essentially then the drawing illustrates the manner of connecting a battery unit 8 to the lower motor section although it is to be understood that the same configuration may be employed between individual battery units as well. The battery unit 8 is terminated at its lower portion in a downwardly extending tubular member 6i). This provides a hollow cavity within which an upwardly extending plug 5I from the next lower battery unit or from the motor section may enter. Plug 6| is preferably formed in stepwise sections of smaller crosssectional diameter. A cylindrical electrical contact 62 is positioned around a portion of plug 6| having an intermediate cross-sectional area. Insulating material 'l2 serves to electrically insu- In operation, the

late the metallic contactor 6I from the remaining portion of the apparatus. An electrical lead 63 extends from contact 6|, through a passage provided, downwardly to the motor section of the apparatus or, if desired, to a lower battery section. A spring contact 64 carried within the hollow'cavity provided by tubular member 60 of the battery unit 8 is positioned to make contact with the contact 6I, and a conductor 65 from the spring contact 64 extends upwardly to the upper battery section. As described, electrical contact from an upper battery section 18 to the lower motor section may be made through conductor 65, leaf contact 64, cylindrical contact 62, and conductor 63. The remaining electrical connection required may be provided by grounding the battery and motor of the apparatus to the metallic shells in which they are contained. A ground contact 66 may then be positioned within tubular member 60 so as to make contact with the plug 6I so as to complete the electrical circuit. The tubular termination of the battery section 8 is preferably provided with lugs or shoulders 6l. The shoulders 6l are intended to contact pins or collars 68 xed to or positioned on plug 6|. By this provision, when the entire apparatus'is supported from above, the battery unit 8 will carry the motor section by contact of the shoulder 61 with the collar 68. In this condition contact 64 will not make contact with contact 6| However, when the apparatus has been lowered to the bottom of the bore hole, the weight of batteryl unit 8 and the upper portion of the apparatus willcause the battery unit to slide downwardly to the position illustrated. This will complete the electrical circuit as formerly described.

This arrangement to permit the sliding of battery 8 downward into electrical contact with the motor section causes the motor to begin operation when the apparatus has reached the bottom of the bore hole;

In order to permit certain of the battery units t0 be Withdrawn for replacement at the surface of the earth without interrupting the operation of the drill bit, it is particularly contemplated that at least one battery unit above the lowermost battery unit be built without the pin or collar 68. As a result, if a retrieving tool is dropped down the bore hole to engage the spearhead at the uppermost portion of the apparatus, the upper battery units may be pulled from the bore hole while leaving one or more of the lower battery units at the bottom of the bore hole. These units will serve to power the drill bit during the period of time required to introduce fresh or recharged units by dropping them downwardly into the bore hole.

When drilling operations are completed, and it is desired to pull the entire apparatus from the bore hole, it will then be necessary to first retrieve the replaceable battery units and to then recover the lowermost section of the apparatus by engaging the Spearhead 69.

As described, the apparatus is of a nature to permit mud circulation from the uppermost part thereof downwardly through the entire apparatus to a point adjacent the drill bit. To follow the passage of mud through the apparatus it will be noted that the drilling mud enters the apparatus through the ports I at the upper portion of the cuttings separator section. The drilling mud is passed downwardly through channel 6 through the battery sections of the apparatus. Beneath the battery sections channel 6 enters the cavity 46, adjacent the shaft of m-otor 2.

asados? Packingglandswd, sealing off cavity 46 Vcause the drilling mud to pass into the shaft 20 of motor 2. The drilling mud then passes into pumpVv 3 through the ports 4'! arranged on the impeller of the pump and opening into the channel 5 -of the motor shaft 2Q. The drilling mud isl-forccd by the pump into the lowermost channel 6a which may be arranged adjacent the outer -portion'of the apparatus housing to permit the mud t bypass the gear reduction system .5. The drilling mud is then brought into a lower cavity 49 surrounding the shaft 2l of the drill bit 4. Again. packing glands 50 are employed above and below cavity 't9 to contain the drilling mud in the cavity adjacent drill bit shaft 2|. The lower portionY of shaft 2| is hollow and is provided with ports l so that the drilling mud from cavity 49 may pass t0 the inside of shaft 2l through ports5l. The drilling mud may then be expelled through the lower termination of the channel in the drill bit shaft 2l.

It will be noted that the motor shaft is directly coupled to both the mud pump 3 and to -the gear reduction system 5. In the manner illustrated and described, this permits the motor vto power both the drill bit and the mud pump.

It is apparent that in place of the batteries described, other stored power sources may be employed together with suitable motors to be driven thereby. For example, a compressed gas system, or a chemical .power system may be employed.

.What is claimed is:

1., A self-powered apparatus for drilling a vborehole comprising an elongated body, a drill bit rotatably supported on the lower end of said body, a motor in said body driving said drill bit, ajpump in said body driven by said motor, bore- ;hole engaging means carried by said body to prevent rotation of said body in the borehole, at least one stored power section connected to the top .of said body, means for furnishing power from ysaidlpower section to said motor, a fluid .passageway extending through said body from -a-port adjacent said drill bit to a port at the top of said body, and a fluid passageway extending Avertically through said store'dpower section and communicating with said passageway -in said body whereby fluid circulation through apath `within the Yentire length of the apparatus in the borehole and a path through the entire length of lthe'annulus between the apparatus and the bore .hole maybe established.

2. Apparatus as dei-ined by claim 1 in which at least one of said stored power sections is releasably connected to vsaid body whereby said section may be removed from the borehole byfretrieving means lowered into the borehole.

'3. Apparatus as deiined lby vclaim `1 in 4which atleast the uppermost stored power section terminates at its upper end in a portion of reduced rcross sectional area, thereby defining with the borehole an enlarged annulus of larger `cross sectional area than the annulus surrounding the body, said passageway through said storedpower section terminating in ports above the lower end of said reduced portion, whereby cuttings will tend tov settle in said enlarged annulus below `the point Aof entry of fluid into said passageway.

4. Apparatus asdened byvclaim lin which said stored power sections are electric battery sections, said motor is an electric motor and said means for furnishing power to said motor is an electrical circuit.

5. Apparatus as dened by claim 4 wherein the battery section immediately adjacent the body is mounted in slidable relation to the body for limited movement between a rst position and a second position, said electrical circuit including contacts in said battery section andl in'said body whereby the battery is connected to said motor in only one of said positions.

6. A self-powered apparatus for drilling a borehole comprising an elongated body adapted to pass through the borehole, a drill bit rotatably supported on the lower end of said body, a pump in said body, a motor in said body driving said drill bit and said pump, borehole engaging means carried by said body to prevent rotation of said body in the borehole, a rst battery section connected to the top of said body, a second battery section releasably connected to said first battery section whereby said second battery section may be removed from the borehole by retrieving means, a iluid passageway `extending through said body from a port adjacent said drill bit to a port at the top of said body, fluid passageways extending vertically through each of said battery sections and communicating with said passageway in said body, and an electrical circuit connecting each of said battery sections -to said motor.

HENRY J. OGORZALY. BEN W. SEWELL.

References Cited in theiile of this .patent UNITED STATES PATENTS Number Name Date 1,350,059 Blackwell Aug. 17, 1920 1,477,563 Hirschfeld et al. Dec. 18, 1923

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