Rotary air drilling head

3,285,352

J. M. HUNTER

ROTARY AIR DRILLING HEAD

Nov. 15, 1966

Filed Dec. 3, 1964

Sheets-Sheet 1

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Nov. 15, 1966

3,285,352

J. M. HUNTER

ROTARY AIR DRILLING HEAD

<img file="US3285352A_D0002.tif" />

3,285,352

Patented Nov. 15, 1966

United States Patent Office

3,285,352

ROTARY AIR DRILLING HEAD Joseph M. Hunter, 1505 Indian Springs Road,

JmJjjjna Pa*

Filed Dec. 3,1964, Ser. No. 415,604

Claims. (Cl. 175—214)

This invention comprises a novel and useful rotary air drilling head and more particularly pertains to a drilling head for rotary drilling apparatus adapted to be detachably mounted in a well casing head for packing and wiping the kelly bar of a rotary drill string and for deflecting. solid particles ascending the well casing with the drilling air or drilling fluid into the drilling fluid outlet of the casing head.

In rotary drilling rigs the kelly bar which is attached to, supports and serves to impart rotary motion to the drill string is connected to its source of power, as by a rotary table, on the drilling platform of the well casing head. As the drilling operation progresses, the drill string is rotated by the power source and is progressively lowered into the well bore. At the uppermost portion of the drill string there is secured a kelly bar which serves the plural functions of supporting the drilling string during raising or lowering of the latter, transmitting power from the power source to the drilling string for rotating the latter and for supplying the drilling fluid to the interior of the drilling string. The kelly bar is required during its operation to rotate in and slide axially through a drilling head or packing member which serves to guide the kelly bar, pack and seal the latter against the escape of oil or drilling fluid through the well casing head about the kelly bar.

It is the primary purpose of this invention to provide a drilling head having a greatly improved coaction with the kelly bar or drill string and also with the well casing head.

A further important purpose of the invention is to provide a drilling head in accordance with the preceding object which shall enable and permit a slight lateral shifting of the drilling head with respect to the axis of the well casing in order to allow the drill string to accommodate slightly off-center positions which it may assume during the drilling operation.

Another object of the invention is to provide a drill head in accordance with the foregoing objects which shall be specifically adapted for use with rotary drilling of the air drilling type in that it will provide for protecting the drill head and the packing elements thereof from damage by solid pieces of the formation penetrated by the drill bit or other particles and which are conveyed upwardly through the well casing by the air drilling fluid, and will deflect said solid particles through the drilling fluid outlet opening of the casing head.

A further and more specific object of the invention is to provide a drilling head construction in conformity with the foregoing objects which shall include a hollow outer body having means for removably seating and sealingly engaging this body in a casing head while permitting lateral shifting of the body upon a seat in the casing head, together with means for rotatably journaling in the body a hollow guide body through which the kelly bar of the drill string is axially slidable but nonrotatably received and which shall include an improved bearing and sealing engagement of the hollow body with the kelly bar..

A still further object of the invention is to provide a drill head assembly in accordance with the preceding objects which shall include means for firmly securing the guide body within the outer body of the drilling head in a manner to permit lateral shifting movement but preclude axial movement therein and which shall include a means for effecting the efficient lubrication of the rotatable guide body within the outer body of the assembly.

Yet another object of the invention is to provide a drilling head assembly in accordance with the preceding objects which shall include as a removable lower component thereof a combined particle deflecting means and a wiper for the kelly bar.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation las more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective view of the drilling head in accordance with this invention;

FIGURE 2 is a view in vertical longitudinal section taken upon an enlarged scale through the drilling head of FIGURE 1 and substantially upon the plane indicated by section line 2—2. thereof, the position of the kelly bar with respect to the drilling head being shown in ph antom therein;

FIGURE 3 is a fragmentary view in horizontal section taken upon an enlarged scale substantially upon the plane indicated by section line 3—3 of FIGURE ’2 and showing further details of the lubricating system of the guide body and of the mounting means for securing the drill head in a well casing head;

FIGURE 4 is a fragmentary detail view taken in horizontal section upon an enlarged scale substantially upon the plane indicated by section line 4—4 of FIGURE 2 and showing in particular a lubricant impelling construction forming apart of the invention;

FIGURE 5 is a view in vertical longitudinal section through a portion of the well casing head and showing the mounting of the drilling head therein with the latter being shown in elevation; and

FIGURE 6 is a further detailed view taken upon an enlarged scale of a portion of the internal packing construction in accordance with this invention.

In the accompanying drawings, attention is directed first to FIGURE 5 wherein the drilling head forming the subject matter of this invention is indicated generally by the numeral 10 and is shown mounted in the casing head 12 at the upper end of a well casing 14, this casing head having a retaining means 16 for its open upper end and by means of which the drilling head 10 is removably secured to a seat 18 within the casing head. The well casing head is further provided with a drilling fluid outlet port 20 by means of which the drilling fluid, carrying with it formation particles and other solid particles is discharged from the well casing. Also indicated by the numeral 22 is an air nozzle connected as by a conduit 24 to any suitable source of air under pressure and by means of which a jet or stream of air is directed into the discharge or outlet to facilitate the flow of drilling fluid and particles carried thereby from the casing head.

The drilling head of this invention cooperates with a drilling string, not shown, but which includes at its upper end the usual kelly bar indicated in phantom in FIGURE 2 by the numeral 30. As is well understood in the art, the kelly bar and through it the drill string is supported and raised or lowered in the well bore in accordance with the drilling operation, and is rotated by a source of power applied through the kelly bar, while drilling fluid either liquid or air is supplied through the interior of the hollow kelly bar and thence through the drill string to the bottom of the well bore, from any suitable and conventional source of the drilling fluid, not shown, and during its ascension of the annulus between the drill string and the well casing carries with it formation particles cut by the drill bit and any other solid particles where they

3,285,352 ³ are subsequently discharged from the well casing through the outlet 20. Inasmuch as the general organization and arrangement of this portion of a drilling apparatus is well known to those skilled in the art, and since the present invention resides within the actual structure, operation and association of the drilling head 10 with the well casing head and the kelly bar, a further description thereof is deemed to be unnecessary.

Referring particularly to FIGURES 1, and 2 and 5, it will be observed that the drilling head 10 comprises a hollow outer body 32 having a central opening or bore 34 extending axially therethrough. The exterior of the outer body 32 adjacent its upper end is provided with sets of laterally outwardly projecting lugs 36 which are adapted to rest upon and seat in correspondingly shaped recesses or sockets in the open upper end of the casing head 12, to thereby removably seat and support the drilling head in the upper end of the well casing head. It should be observed that it is within the purview of this invention to establish sufficient lateral clearance between the outer ends of the lugs 36 and the corresponding surfaces of the sockets forming the seat 18 to allow the drilling head to shift slightly laterally in the casing head if desired. In other instances, however, a snug fit may be provided which will prevent any lateral shifting of the drilling head upon its seat in the casing head 12.

The previously mentioned retaining means 16 is adapted to engage the top surface of the lugs 36 and thereby clamp and retain the drilling head against its seat 18 in a removable manner.

Upon the lower portion of its external surface, the drilling head body 32 is provided with external packing or sealing means 40 which slidably and sealingly engage the internal surface of the casing head 12 to prevent escapement of fluid therebetween.

As previously mentioned, the outer body 32 is provided with a central opening or bore 34 therethrough. This bore receives and rotatably journals therein an inner or hollow guide body 42, having, as shown best in FIGURE 3, an axial guide bore 44 therethrough which is non-circular in cross-section to correspond to the cross-sectional configuration of the kelly bar 30, so that the latter is non-rotatably but axially slidably received in the inner or guide body 42.

In its upper portion, the central opening 34 is diametrically enlarged to provide a cylindrical bearing recess 46 in which is secured in any suitable manner an anti-friction bearing member 48 which rotatably journals the guide body 42. Opening downwardly from its top surface, the outer body 32 is provided with a plurality of vertically disposed and circumferentially spaced lubricating bores or passages 50 whose upper ends open into an annular lubricant reservoir 52 which may be supplied with lubricant from time to time as necessary through the lubricant inlet passage 54 closed by a plug 56. In this manner, lubricant is continuously supplied to the bushing or bearing member 48 to thereby reduce the wear between this member and the diametrically enlarged bore 46 and/or the surface of the inner guide body 42.

Adjacent its upper end, the inner guide body 42 is provided with a diametrically enlarged laterally projecting flange or rib 58 having a bottom flat planar surface 60 which rests upon the top of a thrust ring 62 which in turn seats upon a shoulder of the further counterbored portion of the guide bore 46 which constitutes a part of he lubricant reservoir or channel 52, and which also serves to bear against and retain the bushing 48 against the shouldered seat 64 at the junction of the counterbore 46 with the bore 34. A retainer in the form of a ring or .flange 66 is detachably secured as by fasteners 68 to the upper portion of the annular rib or ring 58 and overiji·» a further ring 70 received in the counterbore 72 at i Jke Uppermost portion of the bore 34.

Μΐΐβ** lower portion pf the bore 34 is diametrically en4 larged or counterbored as at 74 and receives in the upper portion thereof a series of internal packing members in the form of chevrons 76 which rest upon an annular ring 78. Below this annular ring is a mass of compressible 5 packing or sealing material 80 of any desired character such as asbestos or the like, and which is compressively retained as by a lower packing ring 82 urged upwardly as by springs 84. A removable cover plate 86 is detachably secured to the lower end of the body 32 as by means 10 of fasteners 88, and at its upper surface abuts against both the springs 84 and against the lowermost of the external packing members 40 to retain both packings in place.

It will be noted that the bottom surface of the member 15 86 is provided with a pair of circumferentially extending inner and outer sealing channels 90 and 92 into which are engaged the upwardly directed inner and outer sealing rings 94 and 96 respectively of a bottom plate 98. The latter has a laterally inwardly extending flange 100 20 which underlies the inner guide body 42 and is secured to the latter as by fasteners 102.

Detachably secured to the retainer plate 98 as by fasteners 104 is a laterally projecting flange 106 of a combined deflector and oil wiper or stripper 108 of rubber or 25 other suitable material. It will be noted that the upper portion of the member 108 is provided with a cavity 110 therein which is of a conical, downwardly converging nature to facilitate passage of the kelly bar therethrough. The member 108 is provided with an axial bore 112 in 30 its lower portion which resiliently grips and engages the kelly bar to permit sliding movement of the kelly bar therethrough but to wipe oil from the kelly bar and to prevent the escape of drilling fluid or oil upwardly therethrough.

The exterior surface of the member 108 is downwardly convergent or generally conoidal in configuration, having externally circumferentially spaced and longitudinally extending radially outwardly projecting ribs 114.

As will be noted from FIGURE 5, the drill head is so 40 positioned in the casing well head that the deflector 108 is disposed adjacent and extends above the drilling fluid outlet 20 in such a manner as to deflect the upwardly ascending drilling fluid for the air or liquid and the solid particles carried thereby in through the outlet 20 where 45 the injected stream of air from the nozzle 22 will facilitate their removal from the well casing.

It will thus be apparent that this device provides an externally and internally packed and sealed drilling head having means to prevent the escape of fluid between the 5° kelly bar and the drilling head and between the latter and the well casing head. In addition, an improved lubricating means is provided for the inner guide body and the exterior body of the drilling head.

Referring specifically to FIGURE 4, it will be noted that planar, annular bottom surface 60 of the flange 58 is provided with a spiral groove 120 extending thereabout. This groove cooperates with the top surface of the member 62 so that upon rotation of the inner body, the groove serves as a spiral groove pump which feeds oil θθ from the lubricant reservoir 52 across the top of the bushing 48 and between the latter and the inner body for effecting a positive lubrication between these elements.

The branch conduits 51 connect the axial bores 50 with the other side of the bushing 48.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and de70 scribed, and accordingly all suitable modifications and equivalents may be resorted to falling within the scope of the invention as claimed.