Drilling head

Aug. 8, 1961

W. C. GIBSON ET AL

2,995,196

DRILLING HEAD

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United States Patent Office

2,995,196

Patented Aug. 8, 1961

2,995,196 DRILLING HEAD

Wilfred C. Gibson, Fullerton, and Arthur E. Wilde, Big Bear Lake, Calif., assignors to Shaffer Tool Works, Brea, Calif., a corporation of California

Filed July 8, 1957, Ser. No. 670,428

Claims. (Cl. 175—7)

This invention relates generally to drilling equipment, and relates more particularly to rotary drilling equipment for drilling wells in underwater formations.

While the present invention has particular utility in the underwater drilling of wells for the recovery of oil and gas, and is shown and described in such connection, it is to be understood, of course, that its utility is not confined thereto.

There are many problems involved in underwater drilling operations. For example, contamination of the drilling mud must be prevented as well as the escape into the water of undesirable fluids from the well.

It is, therefore, an object of the present invention to provide a submarine drilling head that will prevent such contamination of the drilling mud and the release into the water of undesirable well fluids.

Another object of the invention is to provide a drilling head of this character that will provide an effective seal about the drilling string.

Still another object of the invention is to provide a drilling head of this character so constructed and arranged as to reduce to a minimum wear on the seal for the drill string.

A further object of the invention is to provide a device of this character having effective bushing means for the rotatable sleeve of said device.

A still further object of the invention is to provide a device of this character having novel means for adjusting the bushings.

Another object of the invention is to provide a device of this character having means for guiding the lower end of the drill string, which carries the drill, into the head.

Still another object of the invention is to provide a device of this character that is relatively simple in construction and that is reliable in operation.

A still further object of the invention is to provide a device of this character that may be readily serviced at relatively low cost.

The characteristics and advantages of the invention are further sufficiently referred to in connection with the following detailed description of the accompanying drawings with respect to one arrangement. After considering this example, skilled persons will understand that variations may be made without departing from the principles disclosed, and any structures, arrangements or modes of operation that are properly within the scope of the appended claims are contemplated.

Referring to the drawings:

FIG. 1 is a side elevation of a submarine drilling head embodying the present invention with portions broken away to show the interior construction thereof;

FIG. 2 is a fragmentary top view of one of the bushing or bearing elements; and

FIG. 3 is a fragmentary side view showing the tapped openings for fluid pressure connections to the passages for actuating the locking pins.

Referring more particularly to the drawings, the submarine drilling head comprises a hollow body 10 from which depends a reduced diameter portion 11 terminating at its lower free end in an attaching flange 12 having the usual bolt receiving holes 13 whereby said head may be attached to other apparatus below same.

The portion 11 has an internal bore 14 in which is received a sleeve 15 having a radially extending annu2 lar flange 16 at its outer or lower end, said flange 16 being received in an enlarged annular counterbore 17 at the outer end of said bore 16. Screws 18, received in openings provided therefor in the flange 16 and 5 aligned tapped bores in said flange 12, secure the sleeve 15 within said reduced diameter portion 14.

The interior of the body 10 comprises a cylindrical chamber 19 extending longitudinally of said body and at the bottom of said chamber there is a reduced di10 ameter portion 20 defined by an enlargement or thickened wall portion 21. Within the chamber 20 there is disposed an annular thrust bearing race 22 having an annular flange 23 extending radially inwardly at the lower end of said member.

Within the chamber 19 there is disposed an annular bushing adjusting collar 24 which is wedge shaped in longitudinal section, the base or thickest end portion being disposed at the bottom and adapted to seat on the upper surface 25 of the wall portion 21, said surface 20 25 being normal to the axis of the body. It is to be noted that the collar 24 does not extend to the top of the body 10 and there are elongated slots 26 annularly spaced apart in said collar intermediate the ends thereof.

The interior of the collar 24 flares outwardly from 25 the lower end to the upper end and within said collar are a plurality of bearing or bushing elements 28, 29 and 30, said elements being annular and formed of fibre or other suitable material. Element 28 is at the bottom with the element 29 at the upper end thereof and the 30 element 30 at the upper end of said element 29, the upper surface of the element 30 being in substantially the same plane as the upper end of the housing 10. The outer peripheral surfaces of the bushing elements 28, 29 and 30 have substantially the same taper as the 35 taper of the inside of the collar 24 and the peripheral surfaces of said elements seat on the internal surface of said collar. Bushing retaining screws 32 are provided and are received in openings 33 provided therefor in the cylindrical wall of the body 10, said open40 ings 33 being aligned with the respective slots 26 and tapped openings adapted to receive externally threaded reduced diameter end portions 34 of said screws 32, the body portions 35 of said screws 32 being normally disposed in the upper end portions of the slots 26.

The intermediate bearing or bushing element 29 is in ⁴⁵ the shape of a T in cross section with the T on its side and with the crossed portion at the interior of said bushing so as to provide upwardly and downwardly extending annular flanges 37 and 38. The lower bushing element 28 has a notch in the upper interior corner portion thereof for reception of the flange 38, and the upper bushing 30 is provided with a notch in the lower interior edge for reception of the flange 37.

The bushings 28, 29 and 30 are provided with radial slots 40 annularly spaced apart thereabout and extend⁵⁵ ing from the top to the bottom thereof. The purpose of this arrangement will be described hereinafter.

On top of the body 10 there is disposed a cage 45 and above said cage there is a bit guide, indicated generally at 46, having an annular flange 47 from which ⁶⁰ extends an upwardly and outwardly flaring part 48. Suitable aligned bolt holes are provided in the flange 47, cage 45 and the upper end of the body 10 for reception of bolts 49 whereby the body 10, cage 45, and guide 46 are secured together.

Within the bearings 28, 29 and 30, there is disposed a rotatable sleeve 50 having an inwardly and downwardly inclined portion 51 at the lower end thereof, and at the lower end of the inclined portion 51, there is a depending part 52, the lower end portion of which is operably received within the wear sleeve 15, there being a plurality of O-rings 53 disposed in grooves pro2,995,196 vided therefor in the portion 52 to provide a seal between said portion 52 and sleeve 15. On the flange 23 of the thrust bearing race 22 are stacked a plurality of annular thrust bearings 54 and on the upper end of said thrust bearings is disposed a thrust bearing spacer 56 which is annular and is triangular in cross sectional shape and has an inclined face engageable with the lower inclined side of the part 51 of the rotatable sleeve 50. Below the thrust bearings 54 is an annular chamber 55 from which a drain hole 55α extends to the exterior of the body 10.

Within the sleeve 50 there is an annular stripper rubber 60 having a plurality of plates 61 disposed adjacent the upper end thereof and spaced apart about said rubber. The upper ends of said plates are provided with openings for reception of a wire retainer 63 extending annularly within the stripper rubber 60 adjacent the upper end thereof. There is a mounting ring 64 having a plurality of depending fingers 65 which curve outwardly and slightly upwardly and support the wire 63. The fingers 65 are spaced apart and the mounting plates 61 are operably received in the respective spaces 65α between said fingers 65.

The mounting ring 64 is secured to an outwardly extending flange portion 66 at the bottom of a rotatable sleeve 67 by means of screws 68. The mounting ring 64 and the flange 66 are externally threaded for screwing into the internally threaded upper end portion of sleeve 50, there being a shoulder 70α on said flange to limit inward screwing of said ring and flange into said sleeve 50.

Disposed on the upper surface of the flange 66 is an annular, upper thrust bearing protector plate 69 on which is disposed an annular upper thrust bearing 70 secured in position by a locking ring 72 which in turn is secured against upward displacement by a snap ring 73 received in a groove provided therefor in the sleeve 67 and extending outwardly of said sleeve so as to engage a shoulder 75 at the inner side of the locking ring 72. The locking ring 72 has an external annular groove 76 thereabout for reception of the inner ends of locking pins 78 slidable in radial bores provided therefor in the cage 45. At the outer ends of each of said bores there is an axially aligned cylinder 79 of greater diameter than said bore, in which is slidably received a piston 80 formed integrally on the pin 78. A cap 81 is provided for each of the locking pins 78 and each cap is axially aligned with a respective locking pin and is provided with an outwardly or radially extending flange 82 at the inner end thereof which seats against a shoulder 83 at the outer end of the cylinder 79 and is secured in position by a snap ring 84 provided for this purpose and received in an annular groove provided therefor. There are a pair of passages, 86 and 87, adapted to be connected to pressure fluid lines. The passage 86 communicates with one end of the cylinder 79 so that pressure therefrom will urge the piston 80 and the pin 78 outwardly. The pressure line 87 is connected to the opposite end of the cylinder 79 and pressure therefrom urges the piston 80 and pin 78 inwardly into locking position. The cap 81 is provided with an internal flange 88 which limits outward movement of the pin 78 and also serves as a seat against which the inner end of a spring 89 abuts, said spring being disposed on a reduced diameter portion 90 of the pin 78. At the outer end of said reduced diameter portion 90 there is a washer 91 disposed on a further reduced diameter portion, not shown, of the pin 78, said further reduced diameter portion being externally threaded for reception of a nut 92 which holds the washer 91 on the pin. The spring 89 urges the pin 78 to· the released position, said pin being held in the locking position by the fluid pressure transmitted to the right hand side or outer side of the piston 79.

Means for adjusting the bearings or bushings of the device comprises a bearing adjusting nut 160 received in a recess 161 in the part 21 of the body 10, said nut being held against rotation in said recess. The nut 160 is provided with a tapped bore 162 aligned with bores 163 and 164 in the part 21 below and above the recess 161. An adjusting screw 165 is threaded into the tapped bore 162 and extends through the bores 163 and 164 so that the upper end of said screw engages the lower end of the bearing compression ring 24. Screwing the bolt 165 upwardly will cause said bearing compression ring to be forced upwardly to thereby compress the bearings 28, 29 and 30 against the sleeve 50, which action is aided by the slots 40 in said bearings. Bolt 165 is provided with a lock nut 166. The adjusting nut 160 may also have a horizontal, tapped bore extending inwardly from the outer surface for reception of a set screw 167, the inner end of which is screwed against the side of the bolt 165.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it is thought that it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the invention without departing from the spirit and scope thereof or sacrificing all of its material advantages, the arrangement hereinbefore described being merely for illustrative purposes.