US2586662A - Directional drilling apparatus - Google Patents

Description

J. G. JACKSON DIRECTIONAL DRILLING APPARATUS Feb. 19, 1952 2 SHEETS-Sl-{EET 1 Filed Aug. 20, 1948 g gmc/who@ Joker( Gordon dockeorz w man@ Feb. 19, 1952 J. G. JACKSON 2,586,662

DIRECTIONAL DRILLING APPARATUS Filed Aug. 2o, 1948 2 SHEETS- SHEET 2 Johr? Gordon dockorz Patented Feb. 19, 1952 DIEECTIONAL DRILLING APPARATUS John Gordon Jackson, Denver, Colo., assignor to Eastman Oil Well Survey Company, Colo., a'corporation of DelawareV Denver,

Application August 20, 1948, Serial No. 45,309

1 claim. 1

This invention relates to new and useful improvements in directional drilling apparatus.

One object of the invention is to provide animproved apparatus for drilling an inclined or directional well which apparatus combines a core bit with a defiecting tool, such as a whipstock, whereby a core of the formation may be taken simultaneously with the directional drilling operation.

An important obj ect of the invention is to provide an improved directional drilling apparatus wherein a core bit, capable of taking a suitable core during the drilling operation, is guided by=a whipstock or deflecting tool so that the core is obtained at the same time that the directional or deected bore is drilled; the cutting of the core I l disconnected from the whipstock and showing it `not only providing an axial guide for the bit but f ing, a suflcient core is retained by said bit to provide accurate information with respect to the formation last drilled by said bit.

Still another object of the invention is to provide an improved directional drilling apparatus wherein the bit which is combined with 'the' whipstock or deiiecting tool retains a core of the formation last drilled by the bit just prior to removal of said bit, whereby examination of the core will indicate the success of the directional drilling operation by providing information aS to the formation cut by said bit.

The construction designed to carry out the. invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, wherein an example of the invention is shown, and wherein:

Figure l is a View partly in elevation and partly in section of an improved directional drilling apparatus, constructed in accordance with the invention and showing the bit in position connected with the whipstock,

Figure 2 is a similar View illustrating the b it in position while drilling and inclined or deected bore,

Figure 3 is an enlarged, transverse, vertical, sectional view of the core bit,

Figure 4 is a horizonal, cross-sectional view taken on the line 4-4 of Figure 3, and

Figure 5 is a horizontal, cross-sectional view taken on the line 5-5 of Figure 3.

In the drawings, the numeral I0 designates a deecting tool which is illustrated as a whipstock. The whipstock includes a body portion A which is generally wedge-shaped and which is provided with an inclined guide face II extending longitudinally thereof. The upper end of the body portion A merges into a relatively straight section B which is formed integral therewith and which has itsl upper end connected with a collar C. It is desirable that the collar C, straight sectionB and body Abe formed of one piece. The collar is provided with an axial bore I2 which is formed with an annular shoulder I3 at its lower end.

The usual drill pipe I4 is arranged to have its lower end connected to the upper end of a core bit assembly I5, which assembly is adapted to be detachably connected with the whipstock collar C by means of a frangible shear pin I6. The core bit assembly I5 is clearly shown in Figures 3 to 5 and includes a tubular body I'I having a bore Ila and the upper end of the body is provided with screw threads, whereby the drill pipe I4 may connect therewith. The tubular body I1 forms a coring drill collar and has its lower end internally threaded to receive the upstanding pin I8 of a core bit I9. The core bit is illustrated as a modiiied rock bit including a plurality of cutters 20 and is formed with an laxial opening 2| which communicates with the axial bore 22 of the bit shank.

An elongate core receiving tube 23 has its lower end extending through the opening 2| with the remainder thereof projecting axially upwardly within the bore 22 of the bit shank and the bore I'la of the coring collar or body I1. Suitable radially projecting pins 24 extend radially from the tube 23 and locate the tube axially within the bore of the assembly.Y The upper end of the core tube is secured in a transversely extending supporting plate 25 and said plate is disposed at the lower portion of an outlet opening upwardly through the core tube outwardly through the core tube outwardly through the opening E6.

In the operation of the apparatus, the core bit assembly I5 is connected to the lower end of the drill pipe I4 and the tubular body or coring collar Il' extends through the collar C of the Whipstook. The shear pin I6 mounted radially in the collar C has its inner end threaded into a recess 28 formed in the wall of the body or collar I1 so as to detachably connect the assembly l5 to the whipstock. Thus, the whipstock may be. lowered and oriented into position within the Well bore W by means of the drill pipe I4.

After the whipstock has been properly positioned within the well bore, as for example, upon a cement plug D, the weight of the drill pipe is imposed upon the pin l5 to shear or fracture the same, after which the coring bit assembly I5 and the drill pipe may move downwardly through the whipstock collar C. As is illustrated in Figure 2, the bit I9 is guided downwardly along the inclined face l l of the whipstock and upon rotation of the bit, an oifset or inclined well bore I is drilled. During the drilling operation, the Dit le functions to out a core which moves upwardly into and through the elongate core tube 23. As the drilling continues and the core completely nils the core tube 23, the upper end of the core so taken moves into contact with the curved ole dec-tor or hood 21' which functions to break off the upper end of the core and deflect the broken pieces outwardly through the side opening 25. It will be evident that drilling may continue for any desired time and the core tube 23 will remain lled with a core of the last formation drilled by the bit. The taking of the core which is disposed axially of the core bit assembly functions somewhat as an axial guide for the bit i9 so as to maintain or guide the bit along the inclined path which has been initiated by guiding ofthe bit along the inclined face of the whipstook. This is particularly true in the harder formations and thus, even after the bit has passed the lower end of the whipstock, the axial core functions to maintain the bit in the offset or inclined path.

After the bit has formed the inclined bore I of suiiicient depth, the apparatus is removed and as the drill pipe and core bit assembly are moved upwardly, the bit engages the shoulder I3 at the lower end of the whipstock, whereby subsequent lifting removes the whipstock with the drill pipe.

It will be evident that the construction of the core bit assembly is such that a section of the last formation which has been drilled is retained by the bit, and an examination of this section will provide information as to such formation. In side tracking operations where an inclined bore is drilled with respect to a main bore, wherein the latter has been closed by a cement plug, it sometimes occurs that the bit, after passing the lower end of the whipstock will drift back into the main well bore and in such instance will drill through the cement plug. Obviously, if this has occurred, the section of core which is retained in the core tube will indicate upon inspection at the surface that the bit has entered the cement plug and the operator is advised that the oifset bore has drifted back into the main bore. In any event the ability to examine the final formation through which the drill bit has passed is a distinct advantage and is helpful to. subsequent drilling operations.

As above described, the deflecting tool is coinbined with a particular type of core bit assembly which isV capable of retaining a section of the formation last drilled by the bit; however, the advantages could be obtained by the use of other core bits of different construction since the advantage lies in obtaining a section of the final formation drilled by the bit just prior to removal thereof from the well bore.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claim, without departing from the spirit of the invention.

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

In directional drilling apparatus, the combination with a drill pipe, of a coring colla-r connected to the lower end of the drill pipe and having a side opening above its lower end, a core receiving tube, means including lonigtudinally spaced support members between the tube and collar for mounting the tube in the collar in spaced relation to the inner wall thereof and permitting fluid flow through the space, means at the upper end of the tube connecting it with the side opening in the collar whereby core material at the upper end of a cut core can be discharged into the well bore, a core bit carried by the lower end of the core collar to accomplish the core cutting, a deecting tool having an inclined guide face portion and a collar at its upper end, said guide face portion and collar of the tool being rigidly associated with each other and the collar being oi a size to slidably receive the core collar but of small internal diameter than the overall diameter of the core bit, and frangible means for connecting the collar of the defiecting tool to the core collar in a position where the core bit will be below the tool collar but above the inclined guide surface, said side opening in the collar being such a distance above the core bit as to constitute a large fraction of the length of the guide face of the deecting tool and said defined directional drilling apparatus permitting continuous drilling of the deiieoted bore in the identicaldirection of the guide surface of the deflection surface and to a considerable distance beyond the end of the deflecting tool because of the con-r tinued guiding action of a drilled core in the core receiving tube resulting from the ability of the upper end of the core to be discharged to the side of the collar.

JOI-1N GORDON JACKSON.

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

UNITED STATES PATENTS Number Name Date 1,301,541 Cameron Apr. 22, 1919 1,785,405 Candee et al Dec. 16, 1930 1,834,320 Suman Dec. l, 1931 1,867,024 Oliver July 12, 1932 1,970,761 McVicar Aug. 21, 1934 2,093,607 Howard et al Sept. 2l, 1937 2,171,020 Ackley Aug. 29, 1939 2,401,893 Williams June 11, 1946 2,445,100 Wright July 13, 1948 2,510,386 Denning et al June 6, 1950 2,514,586 Natland et al. July 11, 1950 2,520,517 rlaylor Aug. 29, 1950

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