US1493112A - Rotary core drill - Google Patents

Description

Patentes May e, 1924.

JOHN' E. ELLIOTT, 0F L OS ANGELES,

QALIFORNIA.

ROTARY com; DRILL.

appncanon mea my 1s, 1922. semina. 560,760.

To all 'whom t may concer/n.'

Be it known that I, JOHN E. Enuo'rr, a citizen of the United States` residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and usefulv Rotary Core Drill, of which the following is a specification.

This invention relates to -an improved rotary core drill, particularly of the type by which a sample core is formed and extracted to determine the character of formation encountered.

An object of the invention is to provide a core drill in whichn the core is protected against flushing action of the circulating water and the cuttings of the core bit are directed into the path of the circulating Water;

Another object is to provide a core drill in which thecore will not become jammed or froze 'in the core barrel, and in which the core is subjected to a minimum amount of friction so as to prevent a burning of the core. y

A. further object is to provide a core drill bits, and in which the cuttings of the core bit are directed in the path of the outer boring bits and the outer borin bits formed to urge the cuttings towards t eouter pei ri her of the drill.

arlous other objectsand advanta es will be more fully aplparent from the foI lowing description of t e accompanying drawings which form a part of this disclosure, and which illustrate a preferred form of embodiment of the invention.

' Of the drawings:

Figure 1 is a vertical section through my improved core drill. l

Fig. 2 is a bottom plan view of the cutter head removed from the body.

Fig. 3 is an elevation thereof.

Fig 4 is a detail view illustrating the manner in which the cuttings are removed.

Fi 5 is a detail view showing a modified orm of cutter head.

In drilling wells, particularly oil wells, it is often desirable to obtain sa les of the formation through which the drllling tool A is passing for the purpose of determining the presence or absence of oil or other minerals and for obtaining a record of the various strata encountered, and in providing a core drill for this purpose which will successfully function in the various types of having a central core bit and outer boring up of several sections formation certain requirements must be rigidly adhered' to. As a drill of this charf acter is ordinarily operated in the presence of circulating flushing water which carries the cuttings to the surface, it will be understood that the core, especially when o erat lng 1n soft or sand formations, must e ef` `fectively protected against the {iushing action of the water. This protection is best afforded by providing a central tubular core bit which extends beyond the outer boring bits and by so extending said core bit is becomes necessary to provide'for an effective means for freely disposing of the cuttings of the core bit so its cutting action will not be hampered.

A. further important requirement in a core drill resides in'providing relief for the core immediately after it' is formed or as soon two reasons for this requirement; one of Vwhich is based upon the fact that in deep considerable load pressure, a ccore as soon as formed has a tendency to expand rather y 1,493,112 PATENT l oFFlcE..

475 after it is formed as is practical. There are i -than shrink .with the result that the-core has I a snug fit in the core bit and in the core receiving barrel -wheresuch .barrel is of the same' internal diameter as the core bit. This, during the continued rotation 'of the drill relative to the stationary core will create sufficient friction to cause a burning of the core and destroy its usefulness 'as an l accurate sample' of the formation and its contents. In addition to this, such frictional heat will expandl the core and cause it .to clo or become froze in the bafrrel. nother reason for providing such relief is for the urpose of retaining the core within the dri l, it being evident that after expanding in not again pass downwardly through the smaller core bit.

an enlarged core barrel it can- The core'drill of the `present invention fulfils each of the above 'requirements in the ellicient and. ractical manner explalned in connection with the following detailed description of the preferred form of embodiment illustrated 1n the drawings.

With particular reference to Fig.. 1, the

drill comprises a body 1 screw threaded .on the lower end of a tubular shank 2, which may be of any desired length and following the usual practice may be considered as made of drill pipe,

joint 3 being joined to the top of the shank a tooll i roughened surface,

of a plurality of upwardly directedteeth 2 for connection with a string of drill tubin in the usual manner.'

he body 1 has a central core receiving bore 4 and joined to the body' in alignment -with the bore 4 is a core barrel 5 extending upwardly into and spaced from the walls of' the tubularshank 2. A check valve 6 carried by the upper end of the core barrel 5 permits water 'in said barrel to be expelled into the shank as the. core moves into the lbarrel but prevents the flushing water /entering the upper end of the barrel.

A toolhead 7 is secured to the bottom end of the body 1. by bolts 8 or by any other suitable means and in general terms said tool head comprises a central tubular' toothed core bit 9 havingits bore aligned with and of a lesser. diameter than the bore 4 of the body, and a plurality of outer cutters 10 surrounding the core bit 9.

rlhe upper portion of the bore of the core bit 9 tapers to the larger diameter of the \bore 4 and is provided with a serrated or preferably in the form or toothed tapered sur- 11, such roughened means of retaining the faces serving as a core within the tool. v

As shown in the drawings, the teeth 12 of the core bit 9 extend beyond the cutters 10 and the bit between adjacent teeth 'is chamfered upwardly 13 to provide a means for directing the cuttings from the teeth 12 upwardly and outwardly into the path of the outer cutters 10.

The cutters 10 have their cutting edges 14 Y angled outwardly and backwardly relative to the direction of rotation of the drill so as to urge the cuttings towards the outer periphery of the drill, 'each cutter and each of the teeth 12 of the core bit 9 being provided with proper relief rearwardly of their cutting edges to produce an eiicient cutting action. i v

The body 1 and tool head 7 are providedI with aligned ports 15-16, which communi` cate with 'the space between the core barrel '5 and the ltubular shank 2 and direct the flushing water to the cuttinv edges of the outer cutterslO where it wil pick up and carry the cuttings in suspension upwardly between the tool and the wall of the well In Fig. 4, I have illustrated in a diagrammatic way, the operation of my improved core drill, and in such figure arrows 17 indicate the path' of the cuttings from the core cutting teeth 12 as they are forced upwardly and outwardly into the path of the outer cutters 10, and arrows 18 indicate lthe path of the fiushingwater andthe cuttings carriedy upwardly thereby, it being noted that the ports do not' direct the water directl against, the core bit 9 in a manner whic might and outwardly as at with circular teeth aect the core, but the water is' accanita While the form ot drill herein illustrated an(l"clesc1il)ed is well adapted to fulfill the objects primarily stated, it is to be understood that the invention is not to be limited in this regard, tor it is susceptible ot' ombodiment in various other forms all coming within the scope of the following claims:

1. In a core drill, a body having a tubular shank and a core receiving bore, a core barrel aligned with said boreand extending upwardly from the body within the shank, a central tubular core bit aligned with and of lesser internal diameter than the bore, the upper portion of the inner wall of the bit being beveled from its smaller diameter to the larger diameter of the bore and roughened to frictionally grip a core, and a plulIality of outer cutters surrounding the core shank and a core receiving bore, a core barrel aligned with said bore and extending upwardly from the body within the shank, a central tubular core bit aligned with and of lesser internal diameter than the bore, the upper portion of the inner wall being beveled from its smaller diameter to the larger diameter of the bore and provided l for retaining a core, and a plurality of outer cutters surrounding the core bit.

3. In a core drill, a body having a tubular shank and a core receiving bore, a core barrel ali ed with said bore and extending .upwar ly from the body within the shank, a plurality of outer cutters carried" by the body, and a central tubular core with the bore and -provided with cutting teeth extended below the outer cutters, the corebitbeing chamfered upwardly and outwardl between the cutting teeth with said cham ers extending above the lower edge of bit aligned 2. In a core drill, a body having a tubular l of the bit Wardly from the body Within the shank` a plurality of'. outer cutters carried by the body, and a central tubular core bit aligned with the bore and provided with cuttin teeth extended vbelow the buter cutters and chamfered to directcuttings upwardly and outwardly into the ath of the outer cutters. 5. A cutter hea Afor rotary coredrills, comprising a plurality of circula-rly disposed u outer cutters, and a central tubular core bit provided with cuttingJ teeth at yits lower end, the teeth projecting elow the outer cutters and the bit between the teeth being chamfered outwardly and upwardly beyond the lower edges of the outer cutters to direct cuttings into the path of the outer cutters.

6. In a core drill adaptedy for use on the lower end of aA rotating shaft, tubular mem- `bers providing a core receiving chamber having the lower end thereof of reduced diameter for a relatively short distance, and

flared upwardly and outwardly to substan- 7. In a core drill adapted for use on the lower end of a rotating shaft, tubular members providing a core receiving chamber having the lower end thereof of lreduced diameter vfor `a relatively short distance and 20 flared upwardly and outwardly to substantially the diameter above said reduced portion, the flared portion of-said core receiving chamber being equipped with circular teeth to form a gripping means to prevent the dropping of a core from said chamber, and cutters for forming a core.

Signed at Los Angeles, Calif., this 1st day of May, 1922.

, JOHN E. ELLIOTT.l

Witnesses:

CLARENCE B. FOSTER, L. BELLE WEAVER.

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