US3203713A - Auxiliary drill collar connection - Google Patents

Description

1965 J. H. PANGBURN ETAL 3,203,713

AUXILIARY DRILL COLLAR CONNECTION Filed May 3. 1962 JAMES H. PANGBURN CLAY TRIGG INVENTORS AGENT FIG.|

United States Patent Office 3293,2 13 Patented Aug. 31, 1965 3 203,713 AUXILIARY Dani COLLAR CONNECTION James H. Pangburn and Clay Trigg, both of R0. Box 4364, Oklahoma City 9, Okla. Filed May 3, 1962, Ser. No. 192,103 1 Claim. (Cl. 285-18) The present invention relates to Well drilling and more particularly to drill collars.

In drilling oil wells it is conventional to use a plurality of relatively heavy tubular sections, commonly referred to as drill collars, on the depending end portion of a rotary drilling string to provide sufficient mass or weight for forcing the drill bit into the formation being drilled. Since the drilling operation is formed by rotation of the drill string and a certain amount of lateral bending forces are applied to the drill string, the drill collars have a tendency to crystallize and break off the pin or box end portion. This usually results in an expensive and timeconsuming fishing job.

It is, therefore, the principal object of the instant invention to provide an auxiliary means for connecting adjacent ends of drill collars so that they may be pulled from the drilled hole in the event of a pin or box break.

Another object is to provide a device of this class which does not hamper the circulation of drilling fluid through the drill collars.

An additional object is to provide a device of this class which may be disconnected from the next lower drill collar when a pin or box has broken while the drill string is in the hole.

Still another object is to provide a slip joint type connection for drill collars which is fluidtight.

The present invention accomplishes these and other objects by connecting a tubular member to the wall forming the bore in the depending end of one drill collar and slidably connecting the other end of the tubular member to the wall forming the bore of the upper end portion of the next lower drill collar.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

FIGURE 1 is a fragmentary vertical cross-sectional view of the device connected with the adjacent ends of driil collars and illustrating, by dotted lines, the relative position of the components during normal operation; and

FIGURE 2 is a fragmentary elevational view of the depending end portion of the device.

Like characters of reference designate like parts in those fi 'ures of the drawings in which they occur.

In the drawings:

The reference numeral indicates the device, as a whole, connected with a pair of drill collars 12 and 14. The drill collars are conventional having an externally threaded pin 16 formed on the depending end of the upper drill collar 12 and a cooperating internally threaded box end 18 on the lower drill collar 14.

In carrying out the invention, the bore 20 of the drill collar 12 is enlarged or counterbored a selected diameter and depth from the pin end, as at 22. The inward end of the wall, forming the counterbore 22, threadedly engages the upper end portion of an elongated tubular member ormandrel 24 freely received within the counterbore 22 and having a bore 26 diametrically equal with respect to the bore 29 of the drill collar 12.

The upper or box end portion of the drill collar 14 is similarly counterbored, inwardly of the threads 18, as at 28, a selected depth for slidably receiving a circumferentially enlarged flange portion 30 of the depending end portion of the tubular member 24. The length of the connector or tube 24 is determined by the spacing desired be tween the pin and box ends before connecting the latter to facilitate the use of wrenches in assembly and removal of the unit it). The depth of the counterbore 28 is such that the depending end surface of the tube 24 remains in spaced relation with respect to the inward end of the counterbore 28, not shown, when the pin and box are connected. The drill collar 14 is further counterbored a selected depth, adjacent the inward end of the thread-s 18, as at 32, forming an annular shoulder 34. The counterbore 28 is internally left-hand threaded adjacent the shoulder 34 for threadedly receiving a sleeve 36 having a bore 38 slidably receiving the periphery of the tubular member 24 above the flange 30. The sleeve 36 is provided with an outstanding annular flange 4t], closely received by the counterbore 32 and which seats against the shoulder 34. The inner wall of the sleeve 36 is provided with a plurality of packing or O-rings 42 to seal fluidtight with the periphery of the tube 24. The upper edge surface of the tube flanged portion 30 is beveled inwardly for cooperative engagement with a similar bevel formed on the depending edge surface of the sleeve 36, as at 44. The upper edge surface of the flange 30 and depending edge surface of the sleeve 36 are further formed by inclined surfaces 46 and perpendicular surfaces 48 to define a circumferential series of cooperating ratchet teeth for the purposes more fully explained hereinbelow.

Operation In operation, the device is assembled as described hereinabove. In the event the pin or the box of a drill collar breaks, the upper portion of the string may be lifted thus engaging the flange 30 with the depending end of the sleeve 36 to lift the entire string from the well. If, however, the drill bit is stuck or it is desired to part the string at a drill broken collar for washing over the portion of the string remaining in the hole, the ratchet teeth on the flange 30 is engaged with the ratchet teeth on the depending end of the sleeve 36 and the drill string is rotated in the conventional clockwise direction wherein the respective ratchet teeth act to unscrew the sleeve 36 from the drill collar 14.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and we therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than we are limited by the scope of the appended claim.

We claim:

An auxiliary drill collar connector for connecting the adjacent ends of an upper drill collar to a lower drill collar, said drill collars having cooperatingly threaded box and pin ends and having connterbores extending coaxially inward beyond the threads of their threadedly connected ends, comprising: an elongated tubular member threadedly connected coaxially at one end to the wall forming the inward end portion of the counterbore in said upper drill collar, the depending end portion of said tubular member having an annular outstanding flange slidably received coaxially by the counterbore in said loWer drill collar; means sealing the depending end portion of said tubular member fiuidtight within the lowermost drill collar, said means comprising a relatively short sleeve of a size complementary slidably surrounding said tubular member and threadedly connected to the Wall forming the counterbore in said lower drill collar inward- 1y of the threads of the latter and above the flanged end on said tubular member, said sleeve having at least one annular packing ring groove formed in its inner periphery, and a packing ring within the groove of said sleeve; and cooperating ratchet teeth formed on the upper edge surface of the flanged end of said tubular member and the depending end surface of said sleeve, said ratchet teeth being engaged with each other by an expanded telescoped position of said tubular member with respect to 4 said sleeve, whereby reverse rotation of said upper drill collar unscreWs said tubular member from said upper drill collar.

References Cited by the Examiner UNITED STATES PATENTS 338,783 3/86 Ritchie 285-302 X 1,796,611 3/31 Montgomery 285-655 2,180,795 11/39 Christensen 285-4102 X 2,481,404 9/49 Donner 285-356 2,851,252 9/58 Le Bus 285-302 FOREIGN PATENTS 10,570 1903 Great Britain. 867,989 5/61 Great Britain.

CARL W. TOMLIN, Primary Examiner.

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