US1660988A - Drilling tool - Google Patents

Description

Feb. 28, 1192s. 1,660,988

C. A. BUTLER DRILLING TOOL Filed June 21 1925 Patented Feb. 28, 1928.

1,660,988 PATENT OFFICE.

CHARLES A. BUTLER, 0F OKMULGEE, OKLAHOMA.

DRILLING TOOL.

Application filed June 21, 1923. Serial No; 646,896.

This invention relates to well drilling tools, and more particularly to a novel stem and bit adapted for drilling well holes of a relatively'large diameter, for instance, in excess of ten inches, and more specifically, nearer to twenty-four inches.

In drilling deep wells as they are now drilled with cable tools, it is necessary to begin with a very large hole, sometimes twenty-four inches in diameter. After drilling three hundred feet or more of this large sized hole, a string of easing with an outside diameter of about one-half inch less than the diameter of the bore of the well is inserted to shut off water and cavings. After the insertion of this firstcasing, the drilling is continued and a hole the size of the inside of the casing is made until water anda cave-in is again encountered, at which point another still smaller string of casing is put in and drilling continued in the smaller hole. This method is followed until the required depth is reached. At this point, the hole has generally been reduced from twenty-four to five inches.

The large strings of easing are very stiff, and the bore of the well must be straight, or the casing will not go through it. In drilling these large holes, slanting formations are sometimes encountered which cause the bit to glance oil to some extent, digging into the wall of the bore opposite the obstruction and there making a crook in the bore through which the casing cannot follow. This is not so liable to happen in drilling the smaller sized holes, as the drill stem fills the small bore so full that it acts as a guide .to the bit holding it in alinement with the bore" and preventing it from glancing off any obstruction that it may encounter.

Heretofore, it has been considered impracticable to make a drill stem large enough to act as a guide to the bit in drilling the relatively larger sized holes on account of the added weight. Wing construction has been attempted to some extent, but has failed for the reason that a stem with wings wide enough to reach the walls of a twenty-four inch hole would either have to be too short, to keep down the weight, or so heavy that it would be impracticable. Wing construction involving light wings arranged to be attached to the central stem have also been tried, but have not provensuccessful because they constantly got loose and got detached in the bottom of the hole.

The main object of this invention is to provide a drill stem and bit in Which the stem has the advantage oflength together with lightness, while at the same time, is large enough to fill the relatively large hole and act as a guide for the bit. Another object resides in the novel construction whereby it is easy to fish out of the wellshould it break across the stem or become detached.

These and other objects will be apparent from a perusal of the following specification when taken in connection with the accompanying drawing, whereinb Figure 1 is a side view of the stem and Fig. 2 is a view of the detached bit lying in the bottom of the hole;

Fig; 3 is a View of the cutting end of the bit, and u 1 F Fig. 4 is a section on the line 44 of In the construction illustrated, the stem and bit are of sufiicient size to drill a relatively large hole, that is, of a diameter in excess of ten inches. In the present case, the drilling tool is adapted to drill a. hole twenty-four inches in diameter. Accordingly, the stem 1 is constructed as a steel casting formed with a central round core 2 and four integrally cast wings or extensions 3,

each provided with a series of openings 4 of any desired shape formed by coring out the same in the mold. By means of this construction, the stem is provided with wings which are wide enough to reach the walls of the larger sized holesl that are now being drilled throughout the oil country without increasing the Weight of the stem to any great extent. These wings act as guides for the bit in drilling slanting and broken formations, and insure a straight hole. struction is light enough to allow of sufiicient length to make it practical for this use, as the wings are made larger and larger to accommodate holes of increasing diameter the openings are made correspondingly larger, so that the total weight is not greatly increased.

These holes or openings 4 have an addltional function in that they provide means for fishing the tools out should the stem break across the wings. Without these holes, if such an accident occurred, it would be ractical'ly impossible. to recover the stem iiecause the width of the wings would prevent passing a socket over them, but with The conv I these openings it is a simple matter to run a hook down and catch into one of the openings and pull the broken part out.

The lower portion of the stem 2 is provided with the usual socket 5 to screw onto the corresponding threadedcoupling 6 on the upper portion of the bit 7 which is a tool steel forging, provided with openings 8 cut through the wings 9 thereof under the hammer. The cutting edges of the bit extend across the end of the wings 9 at the lower end of the bit. lhe bit has four such wings with cutting edges 11 the full diameter of the bore of the well.

Very frequently the bit unscrews from the stem at the coupling 5, 6, or the pin on the bit breaks oif. In either case, the bit is lost in the bottom of the well. If the bit should be left in an erect position, the driller could run a slip socket down and take hold of the neck of the bit and pull it out, but if as illustrated in Fig. 2, as is often the case, the bit should lean over in a caved out place, the drillers slip socket Would be of no use as the neck of the bit would be out of the hole and the socket would go past the neck instead of over it. Accordingly, the bit is provided with the openings 8 to permit it to be hooked out as in the case of the stem. In

addition to these functions, the apertures 4: and 8 in the stem and bit assist greatly in mixing the sediment as the drilling proceeds.

It is obvious that minor changes in the details of construction and arrangement of the parts may be made without departing from'the spirit of the invention as set forth in the appended claim.

Having thus described the invention, what I claim as new and desire to secure by Letters-Patent, is-- A device of the class described comprising a central portion provided With a plurality of radial guide Wings of substantially uniform radial extension from the axis of the device and extending substantially the length of the central portion, and located CHARLES A. BUTLER.

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