US2562346A - Drilling tool - Google Patents

Description

July 31, 1951 c. E. WHITTAKER DRILLING TOOL Filed Oct. 19, 1945 .INVENTOR. CHARLES E Mam/m? ATTOPA/f) Patented July 31, 1951 DRILLING TOOL Charles E. Whittaker, Los Angeles County, Calif., assignor to Globe Oil Tools Company, Los Nietos, Calif., a corporation of California Application October 19, 194.5,Serial No. 623,237

7 Claims.

1 This invention has to do with a drilling tool and is primarily concerned with a tool operable to aid or supplement the action of a drilling bit, and it is a general object of the invention to provide a simple, practical, efiective tool acting to stabilize a bit and to assure a full sized well bore.

In drilling wells with the rotary method it is common to provide a drilling bit on the lower end of a drill string, usually on the end of a drill collar applied to a drill string, and as the bit is operated by rotating the drill string it is advanced into the formation and forms a well bore.

With the usual equipment, difiiculty is frequently experienced in gaining a straight full sized bore and, as a result, many operators resort to complicated and expensive devices such as wall scrapers, reamers, stabilizers, and like devices, in order to straighten the Well bores and to assure the proper size of bore. Reamers are used above the bit when difficulties are encountered in keeping the hole out to gage and also as an aid in stabilizing the bit and drill collar. When it is desired to stabilize only, the cutters of the reamer are replaced by rollers. In either case, it is not possible in practice to get the cutters or rollers closer to the bit than about four to five times the diameter of the hole being drilled.

It is a general object of my present invention to provide a drilling tool to be used in conjunction with an ordinary drilling bit, say for instance, a roller bit, and which is operable to stabilize the drilling bit and also to cut the well bore, if necessary, to bring it to the desired size. The tool of the present invention is preferably proportioned to be slightly smaller in diameter than the well bit, and it is not located at a point remote from the bit but is very close above the bit so that it serves to stabilize close to thebit and also to assure a full sized bore to a point close to the bit. The hole engaging parts that I provide may be within two-thirds to three-quarters of the hole diameter from the bottom of the hole.

Another object of the present invention is to provide a tool in the nature of an insert or attachment applicable between a bit and a drilling string or a drill collar that does not require any change or modification of the standard drilling equipment and which can be inserted or removed easily and quickly, as circumstances may require.

Another object of the present invention is to provide a tool of the general character referred to in which the parts subject to wear are simple and inexpensive and are readily replaceable,

.making it simple and inexpensive to maintain the .weli p r W k sem m. Teei e e the present invention involves a simple ring carrying cutting teeth, which ring can be replaced as a unit by simply unthreading it from the main body, and in general this removable or replaceable part is very simple and inexpensive as compared with the p'arts ordinaril required in well reaming devices which in and of themselves are usually complicated mechanisms.

Another object of my inventionis to provide a tool of the character described having numerous closely spaced teeth which serve as eiiective stabilizers whereas the'usual reamer, or like tool, has only three parts to engage the wall of the bore.

The various objects and features of my invention will be fully understood from the followin detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. l is a side elevation of the lower end portion of a well drilling string showing the lower end of a drill collar and a typical well drilling bit with the tool provided by this invention inserted between the collar and bit. Fig. 2 is an enlarged View of the tool of the present invention, showing it removed from the drill collar and showin 'the bit in place and the lower end portion of the tool broken away to show its construction and the manner in which the bit connects to it and Fig. 3 is a sectional view of a part of the tool taken substantially as indicated by line 3-3 on Fig. 2.

The tool provided by this invention is useful, generally, in connection with the usual rotary drilling equipment and is particularly useful in connection with the ordinary drilling bit, such as is operated by the usual well drilling string. In the drawings I have illustrated a typical form of the present invention and have there shown a typical drilling bit A involving roller cutters and have shown the lower end portion of a drill collar B to which the bit is usually directly applied. In Fig. 1 of the drawings I have shown the structure that I have provided inserted between the drill collar B and the bit A. In .fact, in Fig. 1 I have shown two units of the present invention connected together or end to end, and inserted between the bit and drill collar, it being understoodthat one or more units or tools such as I have provided may be used, as circumstances may require. In thefo'llowing description I will set forth the details of one typical unit of the present invention,fit.ibeingunderstood that such description will equally apply to the various units that may be used.

The bit A disclosed in the drawings is intended to illustrate merely a typical or conventional well drilling bit and I have. for example, illustrated a bit of the roller type wherein there is a body ID with a plurality of depending legs I I carrying suitable roller cutters I2. A tapered threaded pin l3 projects upwardly from the upper end of the body and is designed to fit into a threaded socket in the lower end of a drill collar, or the like.

The roller cutters I2, in accordance with conventional construction, are pitched, arranged and related to cut a hole or to form a bore of the desired diameter, and they include cutting parts to act on the bottom of the bore, as well as parts to act on the side of the bore sufiicient to bring the bore to the desired diameter. In practice the parts of the cutters provided to define the diameter of the bore project radially somewhat beyond the legs I I and, in practice, these parts often wear down after a short period of use with the result that the bit does not form a bore or full diameter. In practice where a bore is under size and requires reaming or if a new hit is introduced, the parts provided to maintain the diameter of the bore have to ream as the bit is advanced through the previously established bore, and before it reaches bottom, all with the result that in many cases the bit may be somewhat under size even before it advances the hole.

The drill collar B illustrated in Fig. 1 may be the usual heavy tubular body commonly provided on the lower end of a drilling string and having a tapered threaded socket in its lower end to rereceive the pin of a bit or the like.

The tool provided by my invention is in the nature of an insert to be arranged between a bit A and a drill collar B, or the like, and it involves, generally, a body C, a sleeve D detachable from the body, and cutters or teeth E carried by the sleeve.

The body is an elongate tubular element made sufficiently long to carry the sleeve D in the manner hereinafter described and to present a surface that can be effectively engaged by suitable tools to facilitate its application to and removal from a position between the bit and collar. Since the body C is inserted between the bit and collar it is preferably formed at its ends to facilitate direct connection with the bit and collar and in an ordinary situation the body is provided in its lower end with a threaded tapered socket l5 shaped and proportioned to receive the pin !3 of a bit A and it is provided at its upper end with a tapered threaded pin H; to be received in the socket I! provided in the lower end of the drill collar B. It is to be understood that the means I have described for connecting the body to other elements may be varied and that I contemplate that such means may include intervening parts such as subs, or the like. The lower end I8 is preferably fiat and normal to the axis of the body so that the shoulder l9 formed at the upper end of the bit body In can be seated against it. The upper end 20 of the body C is preferably made flat and normal to the longitudinal axis of the body so that it can be seated against the lower end 2| of the collar B or the lower end of another body C as the case may be.

The body C of the tool that I have provided is formed with an enlarged portion 22 intermediate its ends which enlarged portion is shaped to present a downwardly facing shoulder 23 and. a threaded portion 24 below the shoulder.

The threads of portion 24 are preferably coarse and 4 tapered and the shoulder 23 is preferably flat and normal to the longitudinal axis of the body. The lower end portion 25 of the body C which continues for some distance below the threaded portion 24 is somewhat smaller in diameter than the small lower end of the threaded portion 24 so that the lower end portion of the body C is, in effect, somewhat reduced in diameter. The upper end portion 26 of the body C above the portion 22 may be a straight turned part sufliciently long to accommodate tongs or other suitable tools and provided with suitable grooves or wickers 21 to accommodate fishing equipment.

The body C has a circulation opening extending longitudinally through it so that it is, in effect, tubular and in the preferred form of the invention the circulation opening 30 formed through the body C is enlarged at 3| intermediate its ends forming a chamber in the body. A plurality of circulation distributing ports 32 extend from the chamber formed by the enlarged part 3| down and out through the body to discharge where the lower end of the threaded portion 24 joins the reduced lower end portion 25 of the body. Through this construction or formation of ports the major portion of the circulating fluid passes to the bit A to act in the conventional manner, whereas the remainder or a part of the circulation fluid passes through the ports 32 to be discharged downwardly at the lower end portion of the body 0.

The sleeve D that I have provided is preferably a plain or simple sleeve having an upper end portion 40 internally threaded at 4| to receive the threaded portion 24 of the body C. The upper end 42 of the sleeve is preferably flat and forms a shoulder to engage or seat against the shoulder 23 of the body C. The lower end portion 45 of the sleeve D continues downward from the threaded parts 24 and 4| to form a depending skirt which surrounds the lower end portion 25 of the body C with clearance so that there is an annular port or duct 50 between the body and sleeve receiving circulating fluid from the ports 32 and discharging downwardly at a point close to the lower end of the body C. The lower end portion 45 of the sleeve D continues downward to a point close to the lower end of the body C.

The cutting teeth E may, in practice, vary in size, number and character depending upon the service to be performed. However, in the preferred construction I provide a multiplicity of teeth E substantially as shown in the drawings and each tooth has a bottom end portion 60 somewhat below the lower end of the body C and a vertical side part 6| extending upwardly from the bottom 60 a substantial distance and to a point somewhat above the lower end 62 of the sleeve. The lower inner portions 64 of the teeth may be bevelled off substantially as shown in the drawings to provide clearance for the upper end portion of the bit body Hi.

In accordance with my invention I preferably provide hard facing on the bottom portions 60 and the vertical side portions 6| of the teeth and I shape and dress the teeth to effectively cut as the tool is rotated with the bit. It will be understood that suitable cutting edges and the necessary clearance may be provided by shaping and dressing the teeth. In practice the lower or bottom end portions 60 of the teeth can be of limited radial extent. However, I prefer to make the side portions 6| of considerable length so that they are effective in cutting the side of the well bore in order to have a reaming action in the crates and the bit A gets under size the cutters E act to ream the bore established by the bit A.

By providing effective long cutting parts on the teeth E. the tool that I have provided will serve to effectively ream immediately above the bit so that for all practical purposes the well bore is maintained full diameter to its bottom. It is to be observed that the presence of the tool that I have provided immediately above the bit not only causes the reaming action that I have described but further acts in the bore to effectively stabilize the bit and thus facilitates the drilling of a straight hole. As the drilling operation progresses the drilling fluid discharged by the ports 32 passes down through the annular chamber 5!! to discharge out at or between the teeth E and thus serves to keep the teeth clean and to prevent balling up such as might otherwise occur. It is to be noted in particular that through the construction that I have provided the depending skirt portion 45 of the ring D with the teeth E on its lower end portion establishes teeth at or around the upper end of the bit body 10. In fact, it is preferred that the teeth be extended so that their lower ends 60 are actually below the upper end of the bit body, thus bringing the reaming and stabilizing parts that I have provided to a point very close to the cutting parts of the bit A. It is to be noted that the lower ends of the teeth are not only below the shouldered connection between the bit and body but that the distance from the bottom of the teeth to the bottom of the bit is less than the diameter of the bit and consequently less than the diameter of the well bore.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that mayappear to those skilled in the art and fall within the scope of the following. claims.

Having described my invention, I claim:

1. A tool for insertion between a bit and a drilling string including, an elongate tubular body having means at its upper end making connection with the drilling string, threads in the lower end portion of the body receiving and holding the bit, threads on the exterior of the body at the lower end portion thereof, a sleeve surrounding the lower end portion of the body and held thereon by the last-mentioned threads,

an annular series of teeth on the sleeve projecting downwardly and radially outwardly therefrom and surrounding a portion of the bit to cut at the lower end of the body and having an outside diameter greater than that of the body.

2. A tool for insertion between a bit and a drilling string including, an elongate tubular body having means at its upper end making connection with the drilling string, threads in the lower end portion of the body receiving and holding the bit, threads on the exterior of the body at the lower end portion thereof, a sleeve surrounding the lower end portion of the body and depending therefrom, the sleeve being held on the body by the last-mentioned threads, an

annular series of teeth depending from the sleeve and surrounding the bit adjacent thelower end of the body and projecting radially outward from the sleeve to cut a bore larger than the body.

3. A tool for insertion betweena bit and a drilling string including, an elongate tubular body having means at its upper end making connection with the drilling string, threads in the lower end portion of the body receiving and holding the bit, threads on the exterior of the body at the lower end portion thereof, a downwardly facing shoulder on the body immediately above the last-mentioned threads, a sleeve surrounding the lower end portion of the body and held thereon by the last-mentioned threads with the upper end of the sleeve bearing against said shoulder, an annular series of teeth on the sleeve projecting downwardly and radially outwardly therefrom and surrounding a portion of the bit to cut at the lower end of the body and having an'outside diameter greater than that of the body.

4. A tool for insertion between a bit and drilling string including, a tubular body having means at one end for connecting it to the string and means at the other end for connecting it to the bit, there being a downwardly facing shoulder on the body intermediate its ends, a sleeve threaded on the body at the exterior thereof and bearing against the shoulder and having a depending skirt portion projecting below the end of the body to which the bit is attached and cooperating with the body to define an annular space, and teeth on the skirt projecting downwardly therefrom and also. radially outward therefrom to cut a bore larger than the body and to overlie the bit adjacentthe body, the body having a circulation opening communicating with said annular space.

5. A tool for insertion between a bit and drilling string including, a tubular body having means at its upper end for connecting it to the string, means at its lower end for connecting it to the bit and an enlarged part intermediate its ends with a downwardly facing shoulder, a sleeve on the exterior of the body bearing up against the shoulder and having a lower end portion spaced from the body forming a chamber, the body having a circulation port communicating with said chamber, and teeth on said lower end portion of the sleeve projecting radially outward and also axially beyond the lower end of the body. 1

CHARLES E. WHITTAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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