US1848128A - Drill collar - Google Patents

Description

'March 8, 19322.v F. J. -uNDRLlTl-:R

DRILL COLLAR Filed Dec. 26 1929 warum A TTORNE y 'y Patented l Mar. 8, 1932 UNITED STATES "PATENT OFFICE y 'FRANK J'. HINDERLITEB, 0F TULSA., OKLAHOMA, ASSIGNOB TO HINDERLITE TOOL (30H1` PANY, F TULSA, OKLAHOMA, A, CORPORATION 0F OKLAHOMA mum. oLLAn Application led December 26, 1929. Serial 11e-416,467.

M y'invention relates to rotary well drilling apparatus, and more particularly to the'drill -.collar which isinterposed between the drill pipe and bit of a tool string.

In drilling wells with rotary. tools, the working tool or bit is carried at the lower end of a drill pipe and cuttings removed by the bit are flushed from the well with mud-laden fluid circulated through the tool string andI well.- .As greatest torsional strain on the string occurs just above the bit, collars of greater strength and consequently of greater diameter than the drill pipe are interposed at this point for absorbing the exceptionaltorsional or twisting strain incident to the'drilling operation. y

The mud-laden fluid passed through the pipe and collar is ordinarily delivered from the bit with sufficient force to scour the bit and lift its cuttings through the well hole about the collar and pipe, but should flow of the fluid be interrupted, mud precipitating from the fluid will settle on the annular shoulder at the top of the collar and form an obstruction known as a mud ring of sufficient volume and density to interfere-with removal of thel tools.

It is the object of my invention to provide a. drill collar whereby formation of such obstruction may be avoided withoutsacrifice of freedom of circulation of fluid or impairment of strength of the bit coupling, and whereby any formation occurring above'the -collar during the drilling operatlon may be removed to permit'withdrawal of the tools.

In accomplishing this object, I have pro'- vided improved details of structure, the vpreferred form of which is illustrated 1n the accompanying drawings,wherein:

Fig.'A 1 is a perspective view of the lower end of a tool string including a drill collar constructed according to my invention, illustrating operation of the tool in a well hole, shown in vertical section.

Fig. 2 is'an enlarged detail perspective vie of the collar, partly broken away for better illustration. f

Fi ..3 is a similar viewof a slightly modified ormof collar. l

Referring in detail to the drawings:

ed externally and internally, respectively, for

attachment to the ste-m' coupling' 4 and bit shank 5,' 'and an enlarged body portion 10 having longitudinal grooves llrectangular in-cross section, formed between spaced ribs 12 extending from end to end of the body,

and forming Waterl courses for free flow of the circulating fluid therethrough, the upper end of the body portion l10 being reduced to facilitate lift of the collar through the well,

and theupper ends ofthe ribs 12 being tapered toward their forward edges to form cutting tips .13 for cutting a path Vthrough any deposit of mud that may have accumulated in the well above the collar when the tools are being removed from the well hole. The side edges of the' ribs are preferably sharp to effect a reaming action on the wall of the well, and the lower ends of the ribs are also preferably tapered toward their forward edges and extended beyond the lower end of the body to form cutting tips 14 for cutting irregular projections'from the wall of thewell while the drilling is in progress.

In 'the preferred form of structuren the grooves forming the water courses extend in straight lines through the body of the collar, but they may be curved, as shown at 15 in Fig. 3, if desired, to impart an auger action when the tools are in operation.

A tool string equipped with a collar con'- structed according to my invention, may be operated in the usual manner except that circulating fluid delivered from the bit and mixed with cuttings instead of passing up- '-1 wardly around the collar is ejected through the Water courses 1n the collar with sufficient force to prevent' formation of a mud ring over the collar while the drilling is n progress. The cuttin'g tips at the lower ends of theribs remove irregular projections left by the bit on the wa'll of the hole which might tend to deliect the collar, and the large body of the collar holds the tools straight and insures a straight hole. Should a ring form or c'avings accumulate over the collar to an extent which would ordinarily' obstruct removal of the tools, fluid circulated through the water courses during removal of thetools will be ejected from the water courses with sufficient force to cut a way for the collar and avoid the sticking which would otherwise occur.

While 'clearance of the well hole above the collar is the principal advantage desired from y use of a collar of my improved construction,

the other advantages heretofore noted as incident to this principal feature of improvel ment add their measure of utility to the tool.

What I claim and desire to secure by Letters Patent is:

' 1. A drill collar including a body portion having spaced integral ribs rectangular :in` cross section on its outer face formingV grooves rectangular in cross section for forming wa- -ter courses, and having cutting'edges llongitudinally of said ribs for reaming the wall of -lha well hole within which the collar is` employed, said ribs having tapered ends forming transverse cutting edges on said ribs.

2. A drill collar including a body portion having spaced longitudinal ribs on its outer face forming water courses therebetween,

Vedges of said grooves,

said ribs having forwardly tapering tips at their upper and lower ends provided with transverse cutting edges,v the length of said cutting edges being equal to the depth of the water courses, and an upper shank of less diameter than the body portion including a. tapered shoulder joining said shank and the collar.

3. A drill collar comprising a body portion having a tapered and a blunt end and having longitudinally extending parallel grooves in lits outer face so as to form cutting edges along one longitudinal edge and both adjacent end an internally screw threadedshank of less diameter than and integral with the blunt end of said body portion, a reduced shank integral with the taf pered portion of said body portion, and a coupling member carried by the free end of said last mentioned shank.

4. A drill collar comprising a cylindrical body portion having a central bore therethrough and a flat end and a tapered end, longitudinally extending' parallel, spaced apart, radially projecting ribs formed integral with the body portion and forming'water courses therebetween, cutting edges formed on one of the longitudinal edges and both ends of said ribs, a centrally located internally screw threaded shank of less diame-

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